Showing posts with label gadget. Show all posts
Showing posts with label gadget. Show all posts

Wednesday, November 23, 2022

How to check--get the Raspberry Pi CPU temperature simplest way. Use command in terminal.

Type in the terminal:

vcgencmd measure_temp

and you will get result like below:

screenshot - Raspberry Pi - terminal command for get CPU temperature


Or type in the terminal:

cat /sys/class/thermal/thermal_zone0/temp

and you will get result like below:

screenshot - Raspberry Pi - get CPU temperature in terminal command


This is based on the Raspbian or Raspberry Pi OS from Raspberry Pi foundation. So I am not sure about other distro OS.




You can find so many articles out there but I wrote this probably for me. I just don't want to go through all the article for that three letters. It is really simple command.

I'm not native speaker so I might used wrong google search keyword though.


Friday, June 28, 2019

Huawei doing just fine with so much pressure from the USA.

I wrote about this in another blog which I can't put link here because that's totally different blog.
But at least, I will summarize it.


Huawei leading the 5G markets.

Here is the news about Huawei leading the 5G markets:




the Chinese telecom equipment supplier managed to secure 50 commercial contracts worldwide making it the biggest 5G equipment supplier in the world.
....
Nokia and Ericsson take the second and third place with 30 and 18 contracts, respectively.
Huawei is dominating the market due to its 2160 5G SEP patents whereas Nokia holds 1516.
It appears that despite the US ban on Huawei's 5G equipment, the company managed to maintain its leadership worldwide.
quoted from GSMArena.com news - Despite issues, Huawei leads the 5G market with 50 commercial contracts @ June 25, 2019


Huawei CEO Ren Zhengfei recently said that company's expected revenue will decrease about $30 billions. You can read news like this - Huawei says U.S. ban hurting more than expected, to wipe $30 billion off revenue - Reuters @ June 17, 2019
So if there has no 'Huawei ban', they probably had more 5G contracts. Worst situation but Huawei is doing just fine.



Huawei P30 series reaches 10 millions sales.

Many people and medias were saying that smartphone sales will be brutal because U.S. chip makers and OS(Operating System) software company can't sell their products to the Huawei.
I surely agree with that.

But some media reported completely wrong information like this - Huawei price shock? Where can I buy that $130 P30 Pro you mentioned? @ May 27, 2019
I agree that secondhand price will be go down because of Huawei ban. But who want to sell their 1,000 dollars smartphone for 130 dollars?

They think Trump is the God that Huawei ban can destroy a company--easily destroy sold products...or something. Or they think Chinese products are all rubbish that they can get it for free.. Or something.



Huawei shipped over 10 million units of P30 series in 85 days - #MWC19

this smartphone series has now exceeded global shipment of 10 million units in just 85 days.
quoted(include photo) from Huawei Central - Huawei shipped over 10 million units of P30 series in 85 days @ June 27, 2019 by Deng Li



This is news from GSMArena.
....in just 85 days - that's two full months faster than the P20 phones. Also, it's a new 3-month sales record for Huawei phones.

And that's not all -
the Huawei P30 Pro received the "Best Smartphone" award from the European Hardware Awards. The SuperSpectrum and SuperZoom camera technologies were touted as major innovations by over 100 tech editors.

One more thing about smartwatch:
The company shipped 5 million units in the first three months of this year - according to an IDC report that's a growth of 282% year over year. Huawei is now a Top 3 smartwatch maker.
quoted from GSMArena.com news - Huawei P30 series reaches 10 million sales in 85 days @ June 27, 2019


That SuperSpectrum is what I previously wrote about--the 'dark sight' - Huawei P30 Pro has not only super zoom. Dark sight, too. @ June 6, 2019
Huawei P30 Pro can take photo in the dark area so it probably far better than any other better low light camera like P20 series, Mate 20 series and Google Pixel 3 series.

Wednesday, June 12, 2019

Biggest mobile news in Korea is Xiaomi Mi 9 will launch in Korea very soon.


Xiaomi Mi 9 will launch in Korea very soon.

photos from Xiaomi Korea - facebook page
photo source: Xiaomi Korea - facebook page https://www.facebook.com/Xiaomikorea/posts/2466980393536012


I think this is the first photo that appear in online from Lotte Himart facebook page:
photos from lotte himart - facebook page
photo source: Hi-mart - facebook page https://www.facebook.com/himart/photos/a.497185556997055/2265694890146104/



Competition makes better for all of us.....

This is actually great news because Korea smartphone market became terrible for customers--because Samsung dominated market too long.--One of most expensive Samsung smartphone in the world.
No competition is terrible for consumer which led to slow innovation because company just charge more without any improvement.

That's why Huawei ban is terrible for whole world--see this Huawei P30 Pro has not only super zoom. Dark sight, too. @ June 6, 2019
You can see how much Huawei improved P30 Pro from previous P20 Pro.


I tweeted this before because people don't realise how important for having a competition.


If you read  Huawei P30 Pro has not only super zoom. Dark sight, too. @ June 6, 2019, you realise that Huawei already leading the new smartphone camera technology--innovation--but people still believe iPhone or Galaxy was the best smartphone camera in the world.
In truth, even Xiaomi Mi 9--which is one of cheapest smartphone in the world, already taking better photos than Apple iPhone.


You can see the review from DxOMark: Xiaomi Mi 9 camera review - DxOMark @ February 20, 2019.
And you can read this: DxOMark: Xiaomi Mi 9 camera better than every iPhone @ February 20, 2019.


If you read about camera review of Huawei P20, P20 Pro, Mate 20 and Mate 20 Pro and recent P30 and P30 Pro, you can find that video wasn't that great than iPhone or Samsung Galaxy S series.
But Xiaomi Mi 9 is not only good at photos and video footage, too.

It should also be noted that the Mi 9 scored the highest ever in DxOMark’s video tests. With a score of 99, the Mi 9 is the best smartphone you can buy for video footage, according to DxOMark.
quoted from DxOMark: Xiaomi Mi 9 camera better than every iPhone @ February 20, 2019

Now Galaxy S10 5G got one more point--100 than Mi 9 though.


Even if you don't put much stock into DxOMark scores for various reasons, it can't be denied that Xiaomi is offering the full package with the Mi 9. With a top-of-the-line camera, a state-of-the-art processor, an in-display fingerprint sensor, and many other high-end features, a Mi 9 gives you most everything you could want for hundreds less than the competition.
quoted from DxOMark: Xiaomi Mi 9 camera better than every iPhone @ February 20, 2019


Xiaomi Mi 9 will costs around USD $450 which is 6GB + 128GB version.

The Xiaomi Mi 9 in its base, 6GB/128GB tier will cost 2,999 yuan, just about $445. The 8GB/128GB and 12GB/256GB tiers cost 3,299 yuan and 3,999 yuan respectively.
quoted from Xiaomi Mi 9: Official specs, pricing, release date w/ Snapdragon 855, triple-camera, 20W wireless charging, $445 - 9to5Google @ February 20, 2019



Smartphone markets need more competitive price.

It can be much cheaper because there has 6GB + 64GB version.
Someone asked about price in Korea--in Xiaomi Korea's facebook page. Mi 9 wasn't released yet in Korea so I'm just guessing--I wrote it like this:
I think it probably cost around USD $420-ish. Or 420,000 won ~ 549,000 won for 6G 64G version--I'm just guessing.
If it's expensive than that, you can always buy from Aliexpress which you can buy it for USD $385-ish--without tax though.


In Korea, Samsung Galaxy S10 costs about USD $890. And Galaxy S10 plus costs about USD $976. You can compare this price with Amazon--I just saw about $680 for Galaxy S10 and $780 for S10 plus. Why do you think Samsung can charge this much--one of most expensive smartphone in world. Because there is no competition in Korea--that's why I said 'competition is better for all of us.'

In Korea, you can buy much cheaper price but that means you have to pay more for mobile carrier's plan. If you spend so much money to the mobile carrier's plan, you will get discount price for the phone. So it's not really the discount.

So Mi 9 costs less than half price of Samsung's.
So it will be good for the customer and good for the market, too. Because they cannot charge more for the brand-name.

Thursday, June 6, 2019

Huawei P30 Pro has not only super zoom. Dark sight, too.

I heard about Huawei P30 Pro's super zoom capabilities. Because P30 Pro has periscope lens which can optically zoom in for 5x.
It isn't end there because it can do 50x zoom which isn't optical zoom though.

You can easily find article like this:

or you can see super zoom in action from youtube video:



And then suddenly the US president Trump and his administration added Huawei to the entity list which means any U.S company is not allow to do business with Huawei. More simple term is "Huawei ban".

So I didn't have time to know more about Huawei P30 and P30 Pro.


And I just found this youtube video:

The Huawei P30 Pro Is The Low Light Camera King And It's Not Close by ben's gadget reviews.



P30 Pro can take photo in the pitch black--dark sight.

I took screenshot from the video:
Screenshot of youtuber ben's gadget reviews' P30 Pro pitch black dark shot.
As you can see, it was very dark alley. And P30 Pro can take a photo like that.

Screenshot of youtuber ben's gadget reviews' P30 Pro pitch black dark shot.

Here is the comparison shot--P30 Pro vs iPhone XS vs Galaxy S10 vs V40.

Screenshot of youtuber ben's gadget reviews' P30 Pro pitch black dark shot.
Same comparison shot but different location-indoor pitch black shot.

As you can see, P30 Pro made whole new concept of nighttime photography--with just smartphone.
I would say P30 Pro blows competition--Google's night sight, out of the water.
And I'd like to name the P30 Pro's night mode as 'dark sight'.


Here is interesting comments that I'd like to share:
Screenshot of youtuber ben's gadget reviews' P30 Pro pitch black dark shot video's comments.
jim kuan commented:
If Apple were to do this, they will make a huge deal out of it.  They will have convention style announcement and give it names like "Quantum Retina Night" technology of the future.  And Huawei just puts it in their phones and says, "oh, by the way, we got a camera that can shoot in dark." 


Anyway, when I saw that video, I tweeted about it like this:



You probably need more evidence. So I will put some more articles.
Huawei's P30 Pro has the best low-light camera, better even than Google’s Pixel Night Sight, and it sets a new benchmark for night photography.
quoted from Huawei's P30 Pro raises the bar for low-light photography @ April 1, 2019 by Vlad Savov


Very low light: No contest

The P30 Pros ability to shoot in the dark is downright amazing. In fact, the darker it gets, the more stunning the results compared to any other smartphone out there.
quoted from Huawei P30 Pro vs Pixel 3 XL: The ultimate low-light camera comparison @ April 2, 2019


Below one is the good example. Author tried to do the blind test but he couldn't...
Huawei ruined our comparison

The initial idea behind this article was to take the best smartphones available on the market in terms of photographic capabilities, take pictures in dimly lit environments or at night, and then have you vote to choose the best shot. However, Huawei managed to ruin the comparison: P30 Pro in most scenes is unbeatable and too easily recognizable.
quoted from Huawei P30 Pro ruined our night camera blind test @ April 24, 2019 by Luca Zaninello



Huawei sets new standards in mobile photography with P20 Pro--and P30 Pro, too.

Many people think that Google Pixel 3 XL's night sight is game changer. But Huawei P20 Pro and Mate 20 Pro actually beat the Pixel 3 XL include night sight--which not many people know.


Here is the some of things you probably didn't know because people in your country don't use Chinese smartphone.

Marvelous! Huawei sets new standards in mobile photography with the Leica Triple Camera, and....

Overall, the P20 Pro offers the most comprehensive and flexible package, with the best image quality in terms of our comparison devices.....

The big advantage for the P20 Pro is its Leica Triple Camera, which blows the Mate 10 Pro and the competition out of the water.....

Huawei has set new standards for mobile photography with its Leica Triple Camera. The P20 Pro is the device against which all other smartphone cameras will now be compared.
quoted from NotebookCheck.net Reviews - Huawei P20 Pro Smartphone Review @ April 20, 2018 by Daniel Schmidt


I don't really bother to checking out DXOmark score because DSLR cameras and lenses weren't that reliable source to get to know the DSLR camera and lens.
But smartphone was quite simpler than DSLR or mirrorless camera. Because photographer's diversity of photographing chances and styles with variety combination of DSLR camera and lenses makes hard to justify the DXOmark score.


When the Huawei P20 Pro was reviewed, there has no match to any other smartphone.
You can read more details in the review.

Conclusion: Game changer

We are used to every new smartphone camera generation being slightly better than the previous one, but looking at the images and test results from the P20 Pro, it seems Huawei has skipped one or two generations. The results are simply that good. The P20 Pro’s triple camera setup is the biggest innovation we have seen in mobile imaging for quite some time and is a real game changer.
quoted from Huawei P20 Pro camera review: Innovative technologies, outstanding results @ March 27, 2018 by Lars Rehm


You can find similar talking like this about people in your country don't use Huawei smartphone:
A majorly disappointing aspect of this entire test is just how unlikely it is for the US is ever to see a Huawei-made handset.
quoted from Pixel 3 Night Sight vs Mate 20 Pro Night Mode - 9to5Google @ December 3, 2018 by Damien Wilde
I will just quote some:
There isn't tons of detail but from what we had to work with initially, I think that Huawei seems to handle lighting a little better than the Pixel in my experience with both smartphones.....

Instantly with the Pixel and Night Sight, we see a greater level of detail, but it feels a little whitewashed overall.

As you can read this 'a little whitewashed overall', right?


The Pixel's eagerness to whiten up images in Night Sight is....

The Pixel tends to whiten up warmly lit scenes, which we feel does rob them of their ambience....

....it will handle incandescent lights better and preserve the vibe of the scene.
quoted from Night mode ON: Pixel 3 vs. Mate 20 Pro : Night Sight vs. Night mode @ November 23, 2018 by GSMArena team

You can read last part--"preserve the vibe of the scene".

Is this the reason why people trying to take photo of?
If you are familiar with computer, you will know the term wysiwyg--what you see is what you get. Whitening the scene wasn't that great way, right?

I'm not just making this up.
Here is the comment from Pixel 3 Night Sight vs Mate 20 Pro Night Mode - 9to5Google @ December 3, 2018

Screenshot of comments from Pixel 3 Night Sight vs Mate 20 Pro Night Mode - 9to5Google.

Skipper commented:

I use a Pixel 3, but one of its problems is photos look fake. Don't get me wrong, I love tinkering with instagram's filters, but come on, if you compare 3's photos with the 20pro, it's pretty obvious that 20pro is more realistic with 3 physical cameras capturing a "wider" aperture look, while Pixel's digital light enhancement is just that, "digitally enhanced", which mean "fake" look by tuning up highlights and shadows.

SF Media commented:

both are amazing..but the pixel is too bright for a night.



Anyway, Pixel 3's night sight probably improved a lot and Pixel 4 which wasn't come out yet, might be better.

But Huawei P30 Pro again made whole new concept of nighttime photography--with smartphone. And super-zoom, too.

Game changer phones which not many countries were available to buy. Because the U.S president Trump and his administration trying to destroying one private company--Huawei.

Friday, May 31, 2019

$150-ish Xiaomi Redmi Note 7 Global Rom version already support widevine L1.

I don't watch Netflix or Amazon prime so I didn't know what this widevine thing is.
But I could find some question about it in Xiaomi MIUI Official Forum which currently merged with Mi Community.


Xiaomi flagship Mi 8 is still L3.

Mi 8 is Xiaomi flagship smartphone line--Mi series which was released last year and this year, Xiaomi released Mi 9.
So people are saying Mi 8 is Xiaomi's flagship smartphone but why Mi 8 don't support widevine L1 which is important because L1 device only support HD in Netflix and Amazon prime.

Screenshot of Xiaomi Mi 8's DRM Info 1/2

Screenshot of Xiaomi Mi 8's DRM Info 2/2

If you see the first screenshot, you can see the Mi 8's firmware version info. - 10.3.2.0 which is Miui global stable newest version.
And L3 from the second screenshot.


You can read about Widevine from Wikipeida
or I will just quote from important part from Widevine digital rights management explained @ December 11, 2017
Android devices support either L1 or L3 security levels, depending on hardware and software implementations, as does Chrome OS. 
If your device is only L3 compliant, you're capped at sub-HD resolutions. Only L1 secure devices.....play back HD or higher quality content...


Redmi Note 7 launched in Korea and it's widevine L1.

Xiaomi Redmi Note 7 was launched in Korea at April 15, 2019. And this model probably is same model like European version which had global version.
Xiaomi Redmi Note 7 Korean version - Global Version.

After launched in Korea, I heard that Redmi Note 7 support widevine L1 from Xiaomi community in Korea. But I don't have a Redmi Note 7 to screenshot myself.
And I just bought it a few days ago so I did capture the screen.

Screenshot of Xiaomi Redmi Note 7's DRM Info 1/2

Screenshot of Xiaomi Redmi Note 7's DRM Info 2/2

You can see the Redmi Note 7's firmware version info. - 10.2.8.0 which is Miui global stable version.
And L1 from the second screenshot.



HD streaming isn't available yet in Netflix, probably.

I don't subscribe to Netflix so I don't know.
But some people are saying HD streaming wasn't available in Redmi Note 7 which suppose to work because it support widevine L1.
But I heard that you can download HD video files in Redmi Note 7.

I don't know much about this so you should ask about it to Netflix.
And you can check Netflix's help page about the "Using Netflix on your Android phone or tablet".

Saturday, March 16, 2019

Can Raspberry Pi boot from USB flash drive? And about how to do it guide.

Simple answer is 'yes, it can' but read on....
Or skip to the "So I will write summary first:" below.
Or skip to the "Raspberry Pi 3 B+ support USB boot.  How about Pi Zero W? Or other Pi?" below.


Not everyone is beginner, I think.

When people looking for how to guide for installing the OS(operating system), they were probably beginner or very first time trying to use Raspberry Pi. If that's the case, step by step guide might be very good choice.

But even so, it is better to explain general concept, I think.

If someone already knew some computer stuff, he or she probably doesn't need that step by step guide. Because Raspberry Pi is computer that means it is same concept.
For example, someone is Windows user like me and some Windows user knew if computer--motherboard support USB booting, Windows user can simply go to the CMOS setting and do boot from the USB stick.
So I'm thinking Raspberry Pi is computer so it might support USB boot, too.

So I'd like to know whether Raspberry Pi support USB boot or not. Or I might have to do something to get USB boot.
That's what I want to know, right?



So I will write summary first:


BCM2837-based Raspberry Pis which were all the Pi 3 models include compute module 3 and Pi 2 Model B v1.2, support USB host and Ethernet boot.

So if you have any of models with BCM2837, you can follow any general install OS guide (and install to the USB flash memory stick) which you might already knew.

And if you have other models include Pi Zero and Zero W, you need single file on your micro sd card and then it will boot from USB memory stick. So you can boot from USB memory stick and also need micro sd card with single file which I will explain below.



thought about boot from SD and then USB.

I am currently using the multiboot via berryboot.

And sometimes, I felt berryboot wasn't enough what I am trying to do. So I am thinking about like that.
3 or 4 OS on SD card and then 1 or 2 OS from USB flash memory.


So I was googling about it like this:
how do i install raspbian on usb memory


And I clicked below guide:

And read this part:
Important information
This tutorial is out-dated and has been updated here: ....
So I did clicked link which is below guide:

I have a Linux machine but most of my data--Raspberry Pi image file and etc, was on Windows which is my main computer.
So I clicked Windows version tutorial--below link.


I appreciate the detail guides. But when I am trying go through this guide it made me very confusing.
See this "Step 2 – Install Raspbian to the micro sd card"
And then "Note: If you’re using a Raspberry Pi 3+, you don’t need to do step 2. Jump straight to step 3."

"Step 3 – Install Raspbian to the USB Flash Drive"
The process is exactly the same as step 2, but this time we choose the USB flash drive as.....

And here--"If you're using a Raspberry Pi 3 Model B+, you can skip step 4."

"Step 4 – Prepare the Raspberry Pi for boot from USB"

"Step 5 – Boot Raspbian from USB Flash Drive"


Huh?
I realised that it is exactly same step as install Raspbian on micro sd card.

I have Raspberry Pi 3 B+ and Pi Zero W. So I already knew how to installing any OS on micro sd card.


As you can see, it took very long time to figure out.
Unfortunately, I clicked very old guide--May 2013. That probably is the reason though.



Raspberry Pi 3 B+ support USB boot. How about Pi Zero W? Or other Pi?

I am thinking newer Pi can support boot from USB memory stick but how about Raspberry Pi Zero W which I also have.

So I googling about it and found this:


This question already reveal how to do the booting from USB stick.

Quoted from the question.
The older Raspberry Pi's (Pi 1, Pi 2 and Pi Zero) couldn't boot from a USB-device, but the Raspberry Pi 3 has support for it. The Pi and Pi 2 have semi-support for it (using an SD-card with a single bootfile).

So if I wanted to boot from USB stick in Pi 1 and 2, I can place single bootfile--which I don't know it yet.

And other people answered that Pi Zero W use older chip like Pi 1 and 2.

And then I found someone wrote about that single bootfile--bootcode.bin.
And pointed to the source:
Special bootcode.bin-only boot mode section in Raspberry Pi boot modes - raspberrypi/documentation
Quoted from above link:
USB host and Ethernet boot can be performed by BCM2837-based Raspberry Pis (these are all Pi 3 models, and some Pi 2Bs). In addition, all Raspberry Pi models can use a new bootcode.bin-only method to enable USB host and Ethernet booting.

Just format an SD card as FAT32 and copy on the latest bootcode.bin.

This is useful for the Raspberry Pi 1, 2, and Zero models, which are based on the BCM2835 and BCM2836 devices, and in situations where a Pi 3 fails to boot (the latest bootcode.bin includes additional bugfixes for the Pi 3, compared to the boot code burned into the BCM2837).

If you have a problem with a mass storage device still not working even with this bootcode.bin, then please add a new file 'timeout' to the SD card. This should extend the time it waits for the mass storage device to initialise to six seconds.

I'm not 100% for sure yet. But if Raspberry Pi use BCM2837, USB host and Ethernet boot will support.

And I found all the Raspberry Pi specifications from Raspberry Pi - Wikipedia.
Screenshot of Wikipedia's Raspberry Pi Specifications section.
And as you can see, Pi 2 Model B v1.2 uses BCM2837. And all the Pi 3--3 Model A+, 3 Model B, B+ and Compute Model 3, lite, 3+.


So if you have Pi 2 Model B with v1.2, Pi 3 series and Compute Model 3 series, you can just install any OS on USB stick and remove micro SD card.

If you have other version include Pi Zero W, you can format the micro SD card and copy the bootcode.bin file.


Yes, I haven't tried it yet. But I think those are from the Raspberry Pi's official repository.
So I'm sure it will work.



Kali and Raspbian booted from USB flash drive.

I probably have to get more information about it so I just found this:
quoted from above link:
HawaiianPi wrote:
The Pi3 will check for a boot SD card first, before booting from a USB device. If no boot SD card is found in 5 seconds, then it looks for a boot USB device.

I think this is quite similar process as USB boot in PC--desktop and laptop computer.

When I read from above link, someone said some USB disk won't work. And I wasn't sure about it--If it's FAT32, why it shouldn't be.

But first I tried with quite old 8GB USB stick, it didn't work--Pi 3 B+ without micro SD card and Pi Zero W with single file on micro SD card.
So I thought I need to do something.

And I realised this could be compatibility issue. So I put my kind of new memory card read which can read SDXC format card, too.

Tada!


As you can see that micro sd card slot is empty.
Kali lite booted from USB Flash memory stick in Raspberry Pi 3 B+.
That USB memory stick doesn't work with USB boot--I tried like 2+ os and also with Pi Zero W.


This time, I tried same USB memory card reader with Pi Zero W. And it worked well.
And I had to put single file in micro sd card.
Raspbian stretch booted from USB Flash memory stick in Raspberry Pi Zero W.

If you'd like to connect more than two USB stick, portable hard disk or SSD, things became quite complicated. Because Raspberry Pi doesn't know which USB drive to boot from.

So you have to search more about it.


I hope you did learn about the basic concept or process of USB boot in Raspberry Pi.

Friday, March 15, 2019

Adafruit's Portable 5 inch Monitor with HDMI DIY looked interesting. But in reality....


I've seen this video: Portable HDMI Display for Raspberry Pi - YouTube

And I thought it looks very nice and quite useful because it isn't only for the Raspberry Pi--I can use as my DSLR monitor or game console monitor as well--I have a Nintendo NES classic edition which is kind of portable console.
So I'd like to do this....



It's expensive than I expected.

But when I saw inside of it, it shouldn't be easy to do.
Building the portable monitor won't be easy, for sure--I haven't done soldering before. But it requires a lot of parts to buy, too.

And if I do this, I might learn a lot of things about Adafruit, for sure.

So I visited building guide wep page.
Overview | Portable 5in Monitor with HDMI | Adafruit Learning System

And I realised I don't only spend a lot of time, I need a lot of money to building it, too.

  • 5.0" 800x480 TFT Display $29.95
  • TFP401 HDMI Breakout $24.95
  • FPC Extension Board $4.50
  • Powerboost 1000C $19.95
  • 2500mAh Battery $14.95
  • Slide Switch $0.95
  • Tripod Screw Insert $1.50
  • Total: $96.75

I thought this is too expensive for me. I need other things like print 3D case and lots of tools to do this.


So when I go through their guide, I saw that it can powering up the screen through USB.
That means, I can simply use my smartphone powerbank.
So no need to buy Powerboost 1000C and 2500mAh Battery.
And I don't have 3D printer so I don't need slide switch and tripod screw insert, too.

So I need three parts--5 inch display, TFP401 HDMI breakout, FPC extension board.
So total $59.4.



Cheaper or even better alternative--Aliexpress.

That means I don't need to do this.
Because I can simply buy from cheap Chinese store in Aliexpress, like this:
This is screenshot of 5 inch capacitive lcd display from Livetime Store in Aliexpress.
5 inch Raspberry Pi 3 Model B+ Touch Screen 800*480 Capacitive LCD Display + HDMI Cable + USB Cable + CD for Raspberry Pi 3-in Demo Board Accessories on Aliexpress.com

This is 5 inch capacitive touch display. And it costs $38--include free international shipping.
This model was different driver board design than 5 inch resistive display so I couldn't find case for this model.
5 inch resistive display case costs $6 to $10 in Aliexpress.
I can buy 5 inch display with case for about $48.

So it's much cheaper and better(include touch panel) than Adafruit's.
I know this because I just ordered one from there. So I search the a lot of similar--5 inch lcd.


If I wanted to learn about Adafruit, I probably can invest that much time and money.
But now I'd like to more focus on Raspberry Pi--and programming.

So I will buy 5 inch capacitive touch display.


You can also buy other 5 inch screen from Aliexpress like this:

This is the screenshot of '5 inch lcd hdmi' search result in Aliexpress.
Buy 5 inch lcd hdmi and get free shipping on AliExpress.com

This is the screenshot of '5 inch screen' search result in Aliexpress.
Buy 5 inch display and get free shipping on AliExpress.com

When you are searching the lcd screen, it doesn't show up many items. But you can find store that specialize in Raspberry Pi or SBC(single board computer). So you probably have to check Raspberry Pi store one by one.



It looks hard to build but maybe not that much.

At first, I don't think it's easy thing to do. When I saw this link:
On/Off Switch | Portable 5in Monitor with HDMI | Adafruit Learning System
It doesn't seem to easy, does it?
But if you are thinking about portable project, I think it's worth the effort.


I saw the next page. And if I learn about soldering, I think I can do this.
TFP401 Driver | Portable 5in Monitor with HDMI | Adafruit Learning System

And next,
Display | Portable 5in Monitor with HDMI | Adafruit Learning System
This part need just connect and position the cable. After that, screen is working.

Next part is mounting to the case.


Overall, if I learn and practicing soldering, it shouldn't be so hard.

But I still don't have a 3D printer and I don't like spend that much money.
So I will buy from Aliexpress.

Many of web store like adafruit, elements14, sparkfun, pimoroni were probably based on USA or UK so shipping and currency is too expensive to my country--Korea.
And same kind of store in Korea was all imported from those countries so things were much more expensive.

That's why Aliexpress is the best choice--for me. And probably to you, too.

Monday, December 17, 2018

How the sixty dollar console-Nintendo classic mini, costing an arm and a leg?


Summary – Sad story of a sixty dollar console costing an arm and a leg.
quoted from one of Amazon user's Nintendo NES Classic Edition Console review: https://amzn.to/2Gid1mP


I also found similar one from customer Q&A sections @ #Amazon's Super NES Classic item page
Q: Will we ever have a chance to buy this?...
A: ...am willing to pay but when you make it impossible to get except rip-off-bay it makes it meaningless that....


Simply put - Nintendo didn't make enough products and they just kept trying to shutdown the productions because they wanted sell their other main line product like Nintendo Switch.

Here is evidence of what I said was probably true:
Despite the positive reception, journalists were confused about Nintendo's decision to discontinue the unit as announced in April 2017. Nintendo did not say at launch that the system was meant to be only a limited run, and its...
quoted from Reception section of NES Classic Edition - Wikipedia


Their products are selling so well but they were simply stop producing the product. Does it make sense to you?

NES Classic Edition


Nintendo NES Classic immediately sold out

The NES Classic immediately sold out when it was first released in November 2016, with resellers charging hundreds of dollars for the popular product.
quoted from Nintendo's NES Classic and SNES Classic are going out of production - The Verge


more details from Scalping and bootlegs section of NES Classic Edition - Wikipedia
This, coupled with the extremely high demand, prompted internet scalpers to buy as many as they could, so they could resell them with extreme price markups. In the US, prices were commonly set between $200 and $500, compared to its launch price of $59.99.


Sunday, June 17, 2018

answer--not physically destroy hdd, for erase data from a hard disk so no one can ever recover it.


Thinking about selling used hard drives.

Recently I bought external 2.5" hard disk drive because my external 2.5" hard drivers have low on free space. Copied all the data to new hard drive from old hard drives.
Now I have number of hard drivers--external 2.5" 500GB, 750GB and a few desktop PC 3.5" hard disks that no use. So I'm thinking about to sell it.

Before I'm selling, I needed to clean up the hard disk so no one can recover my personal data. I don't much have important data though--I have a lot of piece of writings and ideas. But I don't think people will understand what those a pieces of writing is for.
I know this because some of those ideas, I already wrote in my twitter or blogs but no one seems to understand what I am saying. So I don't much care about those.
But I have been learning photography so I have tons of photos which I'd like to erase it.

So I did googling and came across this--in Quora:
How do I erase data from a hard disk so no one can ever recover it? 


Why would you like to physically destroy hard disk which you spend a lot of money for?

Quite surprise to see so many answered with physically destroy the hard drive.

I thought -
Wow...wows!
Nowadays, everyone is sooo rich that everyone suggest to physically drilling, shredding the hard disk.
I'm not rich so I had to completely erase the data before selling.


I know the simple solution without physically destroying it.

I know how software works--because I was a programmer. So I know very easy and simple way. Download some software--bigger size will be better, useless documents or anything from the internet or your not important things like Netflix movie files. And delete all your data. And then copy the downloaded software, documents and all. And kept copy it(same files over and over--make folder to more easier--Windows will make new name for it like below screenshot) until hard disk became zero-ish byte of free space.
screenshot: overwrite files for make unrecoverable

So when the recovery software or professional try to store data from my hard drive, they will only recover those useless data.
It's THAT simple to permanently erase data.
Yes, it takes time. But it perfectly works.


Yes, someone answered what I suggested--overwrite data to remove personal data.
And someone saying that forensic analyse(or something) still can find a bit of information from there. Sure. That might be true.

That's why my solution makes more sense.

Because my personal data was already replaced by thousands, thousands and thousands of files.
That means forensic analyse take more, more and more time to figure out which bit of information connected to the which part of information. It's like thousands, thousands and thousands of jigsaw puzzles to figure out.
And it will be almost impossible because a lot of pieces were missing.

Loren Forslund answered very interesting one and I think it's very good method, too:
My method is using Ubuntu disks utility to break all partitions down and formatting the drive into one “FAT” partition. Now make 2 equal partitions and format them in EXT4 writing over the drive. Now break these partitions back to one NTFS partition over writing the disk. I’m sure if you had one million dollars worth of DOD equipment and 3 months of time you may get a scrap of something, but I doubt anything useful.


People watched way too much TV shows--CSI kind of TV shows.

Especially this part:
I'm sure if you had one million dollars worth of DOD equipment and 3 months of time you may get a scrap of something, but I doubt anything useful.
 - People were watched way too much TV shows
 - and they were way too much talk about this theoretical ideas.

Let's talk about reality.
I told you that I bought a external 2.5" hard disk which has 4TB space--actual size is 3.63TB.
So I put all my old data to this new hard disk..
screenshot: my external hard disk drive's files and folders

Last time, I had a lot of software and documents from the internet. But when I started taking photos, I had to delete those files because nowadays DSLR or mirrorless camera need bigger space to backup.
And other reason is I can always go online to get those software again.  So I don't need to kept in my hard drive.

So in my case, 50% of files(153,598 / 2 = 76,799 files) were probably personal data. But each photo was like 7 to 24 mega bytes only. I have software, downloaded documents, audiobook from Librivox and games and those were far more bigger size than photos.

So even if I have 50 to 70% of files were personal data(because photos I took), 40 to 80% of space were filled with not personal data. That means 40 to 80% of 0.98 tera byte.

That means if forensic analyse find a bit of information, it will quite likely not my personal data. For example, 70% of space were not personal data means:
other not important things - 1,003.52 giga byte * 70% = 702.464 giga byte
my personal data - 1,003.52 giga byte * 30% = 301.056 giga byte
Because my personal data was only 30% chance to picked up by forensic analyse.


And there has more. I have thousands of photos but do you think all of my photos were all very important photos--which I probably use it in my blog.
Photography is my hobby so technically it wasn't very important data.

Even if so, reality is this:
How many professional photographers really use all of their photos they took, do you think?

And how many people do you think they use their hard drive only for their important data?
Even if that's the case, why do they need 1 to 4 tera bytes of hard disk?

I have important documents but most of my documents(which I kept it in text file format--smaller than Word file format.) takes only a few kilo byte.
So I'm sure that a few giga bytes of hard disk should be enough for their personal--important data.



Reality of un-delete kind of software.

How I know this? Because about 10 or 15 years ago, I tried to recover my important data from un-delete kind of software with no success.
I can see the files with so many other files. But I can't recover it because it was already half destroyed--some new files already overwritten some part of those files.

You've known this, too. Good example is 'corrupted file'. Did you recover that corrupted file?


Reality is this:
Even if that forensic analyse find a bit of byte, what can you do with that part of byte?


It was 10 or 15 years ago experience so I have to check. And found this:
Recovering Deleted Files After Formatting: Is it Possible? | Deleted File RecoveryThere are many debates regarding the possibilities of recovering deleted files among computer scientists. All evidence points to the fact that in order to recover files deleted from recycle bin, or any other part of the operating system, they must not have been written over.

In order to recover a deleted file every sector that included data for that file must be in it’s original condition. Overwriting any part of this file with new data will cause corruption.


As you can see, this professional(??) data recovery company saying things were far different than what many people answered in Quora.
Professional data recovery company saying that they can't recover if it's already written over.
But many people in Quora saying that you can recover it--because you can find a piece of information with forensic analyse(or something). So you must do physically destroy hard drive--drilling, shredding, burning and among other physical way.

See the difference.


Even if you recover the part of file, you probably can't read--because of corrupted. But what many people in Quora saying is it can read--recover it.
* If you seen CSI kind of TV show, they can always recover it, don't they?
Yes, you can recover the random data. But do you think that random data is worth a million dollars with spent a few months or a year of work?



That's why I completely agree with what Loren Forslund said:
I'm sure if you had one million dollars worth of DOD equipment and 3 months of time you may get a scrap of something, but I doubt anything useful.


Reality is extremely different than what people were saying in internet, unfortunately.
This is how people kept getting more wrong ideas.



P.S. I found permanent file delete software:
They also explain same thing--overwrite to make unrecoverable.




Wednesday, March 29, 2017

This is the reality---how Apple fanboy dominated this world. - Reality of web storage service.


I've got photos from friend--

screenshot from Best Of Quora facebook page

I didn't even read whole thing because I know the cost of web storage.

So I wrote in my facebook timeline:
This is the reality---how Apple fanboy dominated this world.
Do you know how much does it cost for 5giga byte storage for internet?
Do you know flickr.com even give you free for about 200 times more size--1 tera byte of hard disk? Of course, they will display the advertisement but it was soo small that you will not even notice it.
Are you living in stone age that you think 5 giga byte of storage were some kind of miracle size?
Go and learn how internet became nowadays.


It wasn't really unlimited storage. And it wasn't started like that.

I was quite strange that Google give unlimited storage because there has limit. What I know is it will reduce the size, that's why I've got only 15 giga byte which isn't free at first, if I'm not mistaken.

Google advertised when you buy the android phone, you will get 15 giga byte of web storage.
I thought that 15 giga byte of web storage was really big about 3 to 5(??) years ago. But actually it wasn't.
Because I'm sharing with all of my google services like email, google docs, drives, photos, videos and even here--my blog service.


See. Actually it wasn't big. Because each product has 3 to 5 giga byte which is almost same as any other service.
For example, wordpress which is same as blogger here, give 3 giga byte of storage. You can read details here-Adding Storage Space — Support — WordPress.com
Other example, dropbox which is same as google drive, give 2 giga byte of storage. You can read details here-How much does Dropbox cost? - Dropbox Help - Dropbox
Onedrive which is same as google drive, give 5 giga byte of storage. You can read details here-Microsoft OneDrive Plans


People--even internet technology news writer, actually don't know why google give 15 giga byte. And they think google gave it for free because it was big.


Some of us know 15 giga byte was actually not big. So does Google.



Unlimited storage but compressed image--that means image quality will loss.

So Google offer the unlimited storage with limited photo size. I probably confused about this but if I'm not mistaken, they reduce the size more than half size if it was even 13 mega pixel. That's why I choose upload photos with original quality. I choose that almost year ago, I think.


Google Photos: Unlimited storage for free, with a few gotchas @ June 1, 2015 By Todd Ogasawara
Google Photo gives you unlimited storage space if you are willing to limit photo resolution to 16 megapixels and video resolution to 1080p. You do have the option to store at higher resolutions, but the storage counts against your Google Drive quota.

But it's not only photo resolution. It will compressed image, too.

Choose the upload size of your photos and videos - Google Photos Help
Photos are compressed to save space. If a photo is larger than 16MP, it will be resized to 16MP.

Or if you can buy a Google Pixel phone, you will get unlimited storage without those limitation. You can read here - Google is giving free, unlimited original-quality photo and video backups with the Pixel phones @ Oct 4, 2016 by Lauren Goode




Wait a sec. So Google only offer that much!?

Facebook, almost everyone using nowadays, right?
I've never seen any limitation of photos. People kept uploading it, don't they?
Yes, reduced photo quality(like Google does or more) and size but they gave almost(??) unlimited size, don't they?

How about Instagram?
Do I heard any limitation about photo uploading?
Yes, reduced photo quality(it wasn't much, I think. More for the size, I guess) and size. But they gave almost(??) unlimited storage, don't they?


How about flickr.com which I mentioned very earlier.
Yes, they offer 1 tera byte of storage.



Do you think do I have to find out all the other websites about the offer? It's enough, right?


See the title of this article. "This is the reality--how Apple fanboy dominated this world."
That's why Quora.com who has best answer. And choose that--Apple fanatic side of story, for the best of quora.



P.S. Slightly different but almost same story - Illogical idea ruled internet--especially social networking sites. @ March 17, 2017 - my other blog.

P.S. (at April 3, 2019): I found this question at quora.com - Why does Google offer unlimited storage for photos via Google Photos app? What's in it for Google?
So many answers include what I mentioned here.
Interesting thing is nobody talked about facebook or instagram. Because I'm sure they know about the websites and very likely using the websites. But they don't even know facebook and instagram gave unlimited photo storage like Google does--I'm sure some of their friends uploaded thousands and thousands of photos.

Wednesday, May 25, 2016

Nexus 7 2013 Marshmallow, won't allow to install app--apk file.

If you are looking for solution in forums, they will probably ask 'why you need install app without Google play store' or 'are you trying to install cracked app--illegally unlocked copyright version app'.

I tell you why I need this.
I bought secondhand Nexus 7 2013 (second generation) tablet for my sister so I don't want to do all the things like google log-in process and wasting my limited internet resources (I don't have unlimited internet access.) for downloading apps and sync the app data,
for just testing the tablet.

I just wanted to install some apps like movie play app, photo viewer app, music player app, camera app and some 3d-ish game app or copy some video file so I can check whether this secondhand tablet will work properly or not.

So I just need to install two to four apps to testing the tablet.


Here is the tablet's version info:
Nexus 7 and Android 6.0.1
Screenshot of Settings -> About tablet in Nexus 7


check 'Unknown Sources' in settings for install apk files

If you searched web for 'how to install app (apk file) in Nexus 7', you will find solution like this
Settings -> Security -> turn on 'Unknown sources'
Screenshot of Settings -> Security in Nexus 7


but this doesn't work. Because tablet still don't allow to installing the app.

Screenshot of Settings -> Storage -> Internal Storage
Screenshot of Settings -> Storage in Nexus 7

'Explore' to install the apk file.
But you will get message like this:
'Cannot open file'.
When you trying to install the apk file, you will get error message like this.



How to transfer apk file in Nexus 7.

Many of Android smartphone and tablet probably will have MicroSD memory card slot so most cases you can copy files easily. And not only that.
They will probably have USB-OTG function which you can simply put the usb memory card to the smartphone or tablet via USB-OTG cable.

But Nexus 7 don't have memory card slot. So what you can do is send file via bluetooth or NFC. Or use internet or connect PC with usb cable.

But it looked like apk file won't allow to do transfer via bluetooth or NFC. So you can do it via internet or connect PC with usb cable.


So I use send-anywhere websites to transfer apk file:
trying to send file via send-anywhere.com

and then use download app to install apk file but I've got same error 'Cannot open file'.
'Downloads' app to install apk file but same error - can't open file

I can transfer to the apk file but can't install it.




Only way to install the app is use android app development tool ADB.

I already install the Android Development Tool on my PC and this article became quite long so I will not explain how to get and use the tool.

You can follow one of these articles:

You don't need install whole Android Development Tool to get ADB file. You can find only ADB file and Android USB Driver for Windows(or possibly your system already have it).


You need to turn on 'USB debugging' option in 'Developer Options'. That means it must turn on 'Developer Options' via clicking 7 times in Settings -> About tablet -> Build Number.
* detail guide is here How to enable developer settings on Android 4.2 | Android Central


Connect tablet to PC and then Window+R to type 'cmd' to enter 'Command Prompt' console mode.
install apk file in Nexus 7 via ADB tools - Windows

Make things easier, copy the apk file in the same directory as ADB file is in, and change apk filename short like this because Windows Command Prompt won't easy to handle long filename.
For example here is 'adb install es.apk'.

Finally, install the apk file via ADB from PC.

So install the File Explorer app like ES File Explorer should be better choice. Because this app will allow to install apk file like this:

install app from ES File Explorer in Nexus 7

install app from ES File Explorer in Nexus 7

installed app from ES File Explorer in Nexus 7


If you need more detail guide about use ADB, you can do similar like this: [GUIDE] How to install APK Files on your Nexus Player | xda-developers forum
This guide is for Nexus Player but most of Android smartphone and tablets were all the same.




P.S. I'm quite confusing because I did this(install apk files) many times with variety of Android smartphone and tablet. Most of times, I just sent apk file via bluetooth and installed easily with turn on 'Unknown sources'.
So this is probably Marshmallow problem. Or Google probably blocked 'Unknown sources' option.