RTC, ADC, DAC, I2C, SPI and CAN for approx £10


6 posts
by wibble_ftang » Sun Sep 23, 2012 5:10 pm
I've just been playing with an STM32F4DISCOVERY board modified to run the real time clock. I've used ChibiOS to give the RPi access to the board over a USB virtual com port. The RPi can get and set the date.

With a little extra work, commands can be implemented which will allow the other peripherals on the microcontroller to be used - examples are available in the ChibiOS source.

More details at http://www.wheeze.plus.com/RPi_and_STM32F4DISCOVERY/
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by rtalcott » Tue Sep 25, 2012 4:24 pm
I received my Discovery board yesterday....it looks a bit complicated for a beginner but should be a great Winter project...and I will need to do everything from a Linux machine...I've never set up a tool chain so this should be educational. I'll be looking forward to your posts.
rt
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by wibble_ftang » Tue Sep 25, 2012 7:17 pm
rt,

ChibiOS development on Debian using the Summon Arm toolchain: http://recursive-labs.com/blog/2012/05/07/stm32f4discovery-chibios-linux/. Haven't tried it on the Pi yet.

Plenty of folks using the Summon Arm toolchain for ChibiOS here: http://forum.chibios.org/phpbb/index.php

I believe that the Pi is great for size, cost, networking, processing, storage and UI but that the real time stuff ought to be delegated to something like the STM32F4DISCOVERY.
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by wibble_ftang » Tue Sep 25, 2012 7:20 pm
rt,

What do you want to do with the board?
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by rtalcott » Tue Sep 25, 2012 7:34 pm
At this point anything BUT my interest is in automation and control. this board was given to me...I am currently unemployed with time on my hands...much time and very little money. I have the Raspberry "under control" and was going to use its GPIO but this board looks like it has much more potential and of course I want to get the Pi to talk to it and exchange commands and data.

I'm OK with Linux and can program simple Python and C (clearly I need to learn more but that should not be a problem) BUT I am a bit intimidated by setting up the development environment on my Linux machine but hopefully that's not as bad as it seems...I have the time to read and try things until they work.

I guess to answer your question I see this as an opportunity to learn quite a bit about working with embedded hardware which may be useful to me. I need to develop basic skills...I need to be able to look at the datasheet/manual for the hardware and understand what it is telling me. So...I'll definitely be following along...NOT capable of contributing much but this looks like a good path to follow.

EDIT: Did not see your first reply on the tool chain when I wrote the above...I will definitely check out your recommendations and I do agree...serious real time needs something like the Discovery board! Thank You for the tips!
rt
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Location: albuquerque nm us
by rtalcott » Tue Sep 25, 2012 7:57 pm
wibble_ftang:

The links are GREAT!

Thank You!
rt

EDIT: nice intro...work in progress...
http://recursive-labs.com/rtos-guide/
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