A20 extras, is it possible?

[zejulios]

Hello,

I need some things on my Android project, I've just ordered an A20 to evaluate, but I don't know if all that I need is possible.
I need an android 4.2 system, that should be able to:

- Have my logo, and only run the applications that I choose, and block all other, is it possible?

- Communicate with SPI or UART, I believe that this is straight forward with A20.

- Have GPS, so I can use TomTom or other turn-by-turn style software, how to do this?
- Should this work (https://www.olimex.com/Products/Modules/GPS/MOD-GPS/) like plug and play? Is there a cheaper device?

- Have 3G support to send/receive data from internet, if I plug a 3G pen it should work?

- I might need bluetooth, is it possible?

- The system should always be running, even in background with the display off, and should turn on by a touch on the screen, is is possible?

- How can I connect a compositive video camera to the system?
- What the alternatives should I have? Wifi camera?

Thanks,
ZJS

[dave-at-axon]

Hi there,

I've found the A20 to be a nice board but to get all the things you need working, you'll need to create your own image by building the source. Not too difficult now that I worked it out You can follow my blog if you want to see this.

http://axonjakarta.wordpress.com

OK, as to the rest.

You can change the boot logo and the boot animation. You can also programme the default background used.

UART is easy but you need to enable some in the script if you need more than whats on the UEXT connectors.

SPI is not enabled by default so you have to add this in the kernel and setup the pins in the script. I use I2C myself and have enabled SPI for a new project so I will have a working image with that soon.

For UART, I2C and SPI you need to write a JNI for Android to access this. There is already a very nice and easy SerialPort API so do a search on this. It works great and you simply get back a file descriptor. Easier to use in Android after this.

3G works out of the box with certain dongles. I have used a Huawei E1550 but so far can't get SMS receive to work. This is a work in progress.

USB Bluetooth should work but need to check the kernel is enabled for it. I don't use this myself.

GPS will work over a UART interface if you enable this in the script and then in the Android configuration. No idea of USB but you can try it.

Always on is easy. You just need to configure it and it will stay on. The screen will dim to off and pressing the screen brings it back on. I've also done work on the boot on power up and this works but not in the Olimex supplied image. You need a custom image to enable this in the script but it does work.

Blocking apps should be possible but you need to run a service to do this. There is an app in the play store that requires a passcode to install and use apps so it can be done. Also remember that you have access to the complete source here so you can make any customisations you want.

Good luck with your project. This is a nice board once you have the ability to build your own images!

[zejulios]

Hello!

Many thanks for your guides, I'll look at your blog to get further information.
To start I'll install Ubuntu on my virtual machine, then follow your steps.
I have to be careful cause buying this board, and adding some stuff will rise a lot the final cost.
The Olimex GPS is almost half the cost of the board...

Regarding the UART I think the ones available on UEXT will be OK.

I'll study your blog, thanks for your help, and blog! .

[zejulios]

I have just received the board, and I'm just doing some "hands-on", and I must confess I was not quite impressed...
I bought this with 10" TS LCD.
First the board was not flashed with 10" LCD ROM, so I have to do it myself, so far so good, since its quite easy to flash with new ROM.
The boot is not very fast, but that's not a issue to me.
The touch screen is not "glued" to LCD, so it might need some calibration, mine was flipped left to right, I had to figure out some touch's before I can reach the calibration, that I thought it wold not be needed, like my tablet...
Then on Apps menu the App name only shows half, its cutted, the image quality is not very good, the speed is not so good, and the touch is not precise and I if I'm too fast it does not detect the touch...

I must confess that I'm quite disappointed at this time with A20 board and Display, but I still believe that I'm doing something wrong, and I must dig further to get better results that I was expecting to be "out of the box"...

If someone can spare me some time, please tell me what I'm doing wrong, or it it's not a defect, is just what it is...

Thanks.

[dave-at-axon]

I have just received the board, and I'm just doing some "hands-on", and I must confess I was not quite impressed...
I bought this with 10" TS LCD.
First the board was not flashed with 10" LCD ROM, so I have to do it myself, so far so good, since its quite easy to flash with new ROM.
The boot is not very fast, but that's not a issue to me.

First boot is always slow (I assume you are using Android) as it creates and installs all the apps etc. I've found the boot after this to be quite quick. Certainly way faster than the old Tiny210 I used from FriendlyArm.

The touch screen is not "glued" to LCD, so it might need some calibration, mine was flipped left to right, I had to figure out some touch's before I can reach the calibration, that I thought it wold not be needed, like my tablet...

I prefer it not to be fixed for my own application as it makes replacement simpler. There is nothing stopping you using double sided tape to hold it in place. I did that for the development unit.

They do state that you will need a mouse for the first installation. After the screen is calibrated, it will be fine and you can run without it.

Then on Apps menu the App name only shows half, its cutted, the image quality is not very good, the speed is not so good, and the touch is not precise and I if I'm too fast it does not detect the touch...

The LCD displays used are very low quality when it comes to comparing what we have been used to with our phones and the nice high resolutions they have. I've seen similar poor displays on the cheap sub $100 tablets that are on sale around here with the same resolutions.

I have an A20 connected to a 7" LCD and a FULL HD LCD TV (it's set for 800 x 480) just now for a development project and the image on the TV Is superb. All the text is sharp and very easy to read, even the GPRS signal is clear. On the 7" LCD it is very poor in comparison. The pixel arrangement on these LCD's is not as good as a mobile phone, even those with the same 800x480 resolution.

I have a 7" capacitive touch LCD I am working on and I am hoping that it's different pixel layout will give me a better image quality!

I must confess that I'm quite disappointed at this time with A20 board and Display, but I still believe that I'm doing something wrong, and I must dig further to get better results that I was expecting to be "out of the box"...

If someone can spare me some time, please tell me what I'm doing wrong, or it it's not a defect, is just what it is...

Thanks.

I don't think you are doing anything wrong. If you are looking for higher quality display, then you'll need to find a better LCD. The A20 will work with a number of different sizes, you just need to have the capability to put something together and adapt the LCD driver settings.

You might like to try and connect to an HDMI LCD TV if you have one and see what you think of the display on that?