Rfm22 telemetry link, MS5706 , and new android software

Hello,

here is the last news of my development.

I received my small 5dof imu, some new sample of the last 24bits integrated pressure sensor from intersema MS5706, I plug everything on my RC receiver and telemetry transmitter and look at what will work... Surprisingly .. everything...

I check the range out of my telemetry board with just a crap antenna, and it is far from being good, less than 100m...

waiting for other antenna to make other check, I must have mistaken something...

beside that I bought one of those ultra-cheap android tablet and started to look what can be done and how...

there is only a dirty wifi module, no bluetooth, a crapy 30pin ipod style dongle that give 2 usb port, 1 rs232 plugged to u-boot and a rj45.

So I plugged one of my board on it and try some things...

I First had some bad luck, the software is fully buggy, the tablet is ultra slow, impossible to root it so it is impossible to access the serial port (for writting), but I succesfully was able to read the serial data that come out of my board via USB CDC bridge.

I'm not good either with java, and the emulator works worth than the real tablet... but I did some stuff that seems to work ;)

... to be continued... (I'm waiting for stuffs...)

@amilcar.lucas : yes, I'm using a rfm22, but I did a mistake calculating my antenna lenght, it is too short, I thing this is why my range is so bad... I'm waiting for various antenna to make different try.

I don't know yet if I'll share the code, maybe... ;)

@Hamish : I spent lot of time on the wen trying to find a way to communicate with my tablet, microbridge was one of my solution, but it is too complicated. And I have lot of trouble trying to root it, and you also need to be root to use the serial api...

as my receiver can be use with a default configuration on which you have nothing to send throught serial line, the only thing I have to do is to look at what comes frome /dev/ttyACM0 (usb cdc). But I spent lot of time trying to figure how to do that, I don't like java either... this way, no need to be root nor to sold wires inside of the tablet ;)

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Comments

Roman April 5, 2011 at 12:48am

yep, will try that on next week-end ;)

hope my antenna will come soon, so that I could try different shapes...
Jeff Taylor April 5, 2011 at 12:45am

The wire looks pretty long already compared to an Xbee even though the frequency is about half. Maybe you can try a 1/4 wavelength antenna while you're waiting for other parts, should be a manageable length and we know it works in a similar application.
Roman April 4, 2011 at 11:03pm

@amilcar.lucas : yes, I'm using a rfm22, but I did a mistake calculating my antenna lenght, it is too short, I thing this is why my range is so bad... I'm waiting for various antenna to make different try.

I don't know yet if I'll share the code, maybe... ;)

@Hamish : I spent lot of time on the wen trying to find a way to communicate with my tablet, microbridge was one of my solution, but it is too complicated. And I have lot of trouble trying to root it, and you also need to be root to use the serial api...

as my receiver can be use with a default configuration on which you have nothing to send throught serial line, the only thing I have to do is to look at what comes frome /dev/ttyACM0 (usb cdc). But I spent lot of time trying to figure how to do that, I don't like java either... this way, no need to be root nor to sold wires inside of the tablet ;)
Amilcar Lucas April 4, 2011 at 3:23pm

Are you using the RFM22 ? Was it the one the gave you 100m ?

Can you share the code ?

RFM22 are legal in Germany and very cheap, so they are quite interesting.
hamish April 4, 2011 at 1:34pm

I wrote how I got the serial ports on my phone to work at http://progsrp.moonfruit.com/#/android-serial/4548697508

but it looks like the best way forward is using an MCU to manipulate the ADB shell thing, like microbridge
hamish April 4, 2011 at 1:30pm

I've been twidling around with interfacing android and arduino, wrote a blog post, check out the comments too
OlivierD. April 4, 2011 at 12:40pm

Very nice layout. I"ll keep an eye on this for sure! Good job Roman!
Roman April 4, 2011 at 2:10am

The android stuff is at the bottom, the top is win32 stuffs ;)

I'm planing to have them look the same...
simonl April 4, 2011 at 2:07am

@roman: Wow! The android stuff looks promising. I'll be following your progress. Please keep us updated.

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