[ell-i-developers] Re: Status report: IP and ARP work on real hardware -- but still WIP

  • From: Pekka Nikander <pekka.nikander@xxxxxx>
  • To: "ell-i-developers@xxxxxxxxxxxxx" <ell-i-developers@xxxxxxxxxxxxx>
  • Date: Wed, 12 Mar 2014 21:55:36 +0200

> Thanks to Ivan's efforts, IP and ARP now work now on real Ell-i hardware.  To 
> baton is now back to me, and I expect to get it merged to the master branch 
> in Runtime either tomorrow or latest during the weekend.

After fixing a couple of tiny bugs, also UDP works now and CoAP responds.  
However, there is still something wrong with CoAP replies, Copper doesn't 
process them.  I haven't pushed the latest changes yet.  Will continue tomorrow.

The relatively unoptimised binary requires 5.5 kB of flash and 2 kB of RAM.  I 
believe maybe 0.5-1kB of flash can be saved with optimising the code somewhat 
more, and currently the packet buffer is way too big compared to what we really 

This means that the runtime and stack should run in some 6 kB of flash and 
maybe 1 kB of RAM, meaning that we should be able to do interesting things with 
the lowest end Cortex-M0 MCUs with 8-16 kB of flash and 4 kB of RAM.  Cf. e.g.


STM32F030F4P6 is immediately available at around $0.50 @ 10k


PS.  Already on Tuesday we got Espruino working on the STM32F4 discovery board. 
 Hence, we are approaching the situation where we will have both the low-end 
Arduino version and the high-end JavaScript version usable.  Not ready, but 
usable.  The main remaining work will be getting Espruino to work with the 
native Ethernet MAC on the STM32F427 MCU; AFAIK that is not supported yet.

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