On 18/08/2015 1:32 p.m., Laeeth Isharc wrote:
I don't know whether D can run on one, but from a quick look perhaps
feasible. Running D on something like this (perhaps it's underpowered,
but looked to have similar spec to what people had been doing with
related ARM cortex processors) would certainly make the point very vivid
that it can be a bare metal programming language.
Only 1Mb of flash RAM for the program - is that enough?
https://learn.adafruit.com/dash-hacking-bare-metal-stm32-programming/programming
https://learn.adafruit.com/dash-hacking-bare-metal-stm32-programming/overview
The Amazon Dash button is a tiny device that orders products from
Amazon.com at the press of a button. It's designed to be put wherever
you store consumeables like paper towels, trash bags, etc. so that you
can easily order more when they run out. The Dash is great at what it's
designed to do, but did you know inside the Dash is a powerful ARM
Cortex-M3 processor and WiFi module that are very similar to wireless
development boards like the Particle Photon? You'll even find there are
easily accessible test pads on the Dash which allow you to reprogram its
CPU and turn it into your own $5 internet button! This guide will
explore how to take apart the Dash and reprogram its CPU to run your own
code.
...
The CPU is a STM32F205RG6 processor which is an ARM Cortex-M3 that can
run up to 120mhz and has 128 kilobytes of RAM and 1 megabyte of flash
memory for program storage.
The WiFi module is a BCM943362 module which in combination with the CPU
make it a platform for Broadcom's WICED SDK.
There's a 16 megabit SPI flash ROM which is typically used in
conjunction with the WICED SDK for storing application data.
An ADMP441 microphone is connected to the CPU and used by the Dash iOS
application to configure the device using the speaker on a phone/tablet.
There's a single RGB LED and a button.
By what you are saying, I believe it should be doable.
Although I'm a little worried for the WiFi support. Do you need to
include the code to drive it beyond wrap up some communication to it?
1mb flash should be enough to run D code on it. If you strip out a good
percentage of druntime and definitely no Phobos.
Although you may be able to mark and use some of that 16mb flash rom as
executable code storage. If that's so, you'll be in a good place to have
more then 1mb. It would require some clever runtime linking tricks however.
I'm probably not the best person to go more in depth about it or the
specific chips. So I won't. Most of my knowledge comes from reading what
others says and talking with Jens Bauer.
