Re: Microcontroller (AVR) programming from smartphone

rodion_gork@mail.ru (RodionGork) wrote:

Hi Friends!
 
Briefly: considering ways of uploading code to microcontroller
(particularly some Atmel's AtMega - same as used for Arduino) from the
smartphone.
 
In details:
 
Programming MCUs (e.g. uploading firmware into their ROM) usually
happens via some proprietary interface (using SPI in case of AVR), or
UART, or JTAG. This generally involves dedicated software on the side of
computer and some hardware (USB to UART or dedicated "serial
programmer").
 
Suppose we want to be able to write simple code using mobile phone -
situation I met with my class of 15+ students with no dedicated lab
having 15+ computers.
 
I tried creating a small system containing two parts: First - html
web-page with a textarea to write assembly code, built-in AVRA assembly
compiler (just compiled to javascript) - and some JS code which can
"beep" the bits of the hex-file containing firmware (via audio). Second
- bootloader for target MCU which uses ADC pin to "listen" to those
beeps via direct wire connected to 3.5 mm audio jack plugged into
smartphone - and "burn" incoming data into flash memory.
 
This works (if you are curious to try, it could be found in my github
page by same username) - however there is a sudden issue: almost half of
students use mobile phones without 3.5mm jack - as nowadays it is the
era of wireless headphones already, I missed the fact!
 
So now I'm looking for further, alternative approaches. For example:
 
- attaching microphone to ADC pin instead of wired connector; code
should be beeped out via built-in speaker of the smartphone (it would be
a bit noisy class, of course) - I actually tried, but was not yet able
to come up with signal recognition algorithm of good enough quality.
 
- blinking data with display and catching it with photo-transistor
attached to ADC or digital pin, haven't tried for it seems like bitrate
would be very low (even though we generally need to upload firmware of
few dozens bytes).
 
Thus I'm open to any ideas / hints / articles on improving either of
these two approaches - or perhaps something completely different which I
may have missed.

+1. I hope you get a good reponse. A worthy project for your students, and
the solution could be used around the world!



--
MRM