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1. 

   gbulmer
   Moderator

   I noticed ST Micro have released their Cortex-M0. The STM32F0, Cortex-M0 is going in the opposite direction to the STM32F4. STM32F0 is slower, with less memory, no USB, no Ethernet, no CAN, no camera, no external memory, etc. But it is low-cost.

   As usual, ST Micro have also released a low-cost evaluation board, which includes the Serial Wire Debugger (SWD):
   http://www.st.com/internet/evalboard/product/253215.jsp
   It doesn't have much on it other than a 64pin part, and the ST-LINK/V2, though it does come with a prototype board

   The STM32F0Discovery at Future Electronics is listed at $7.99 . So that is probably the lowest-cost SWD ST-LINK/V2 at the moment :-)

   It is roughly 2x (or more) an Arduino UNO. The STM32F051 has some extra peripherals like DAC, DMA, capacitive-touch sensors, Infrared transmitter modulation (easy IR RC) compared to an ATmega. I'm interested in robots, so the STM32's fast ADC, and 'advanced motor control' are useful.

   Future are listing the STM32F051 64pin part at $1.60, and the 48pin part for $1.48.

   It just keeps getting better :-)

   Posted 3 years ago #
2. 

   mbolivar
   LeafLabs

   I'm totally unfamiliar with Cortex M0. Do you know if the F0 peripheral registers are anything like what we've got on F1/F2/F4? (I took a look at the st.com link you posted, but there doesn't seem to be a reference manual or datasheet up yet).

   Posted 3 years ago #
3. 

   crenn
   Moderator

   mbolivar, the reference manual is available from here:
   http://www.st.com/internet/mcu/subclass/1588.jsp

   I'd look myself however I've got an exam in 9 hours. After that, I'll probably take a look myself, but I'd suspect it's going to be very similar or near identical to how the F2/F4 series are to allow users to switch between chips (mainly going up the line than down it).

   Posted 3 years ago #
4. 

   gbulmer
   Moderator

   mbolivar - I haven't done a detailed comparison between F0 and F2/F4, but STM32F051 has an Advanced Timer which looks very similar to TIM1, quadrature decoders in some of its other timers.

   GPIO is very similar, though STM32F4 has an 'output speed' option which isn't implemented on the 'F051, and the 'F051 has a Port Bit Reset register (last register, and the rest looks like the same address offsets)

   One thing that interested me is the pair of comparators on the F051, could be very handy. The Infrared Transmitter modulation could make it extremely easy to make an IR remote control, and the capacitive touch peripheral might remove the need for mechanical switches.

   Posted 3 years ago #
5. 

   mbolivar
   LeafLabs

   crenn:

   mbolivar, the reference manual is available from here:
   http://www.st.com/internet/mcu/subclass/1588.jsp

   Thanks!

   gbulmer:

   mbolivar - I haven't done a detailed comparison between F0 and F2/F4, but STM32F051 has an Advanced Timer which looks very similar to TIM1, quadrature decoders in some of its other timers.

   GPIO is very similar, though STM32F4 has an 'output speed' option which isn't implemented on the 'F051, and the 'F051 has a Port Bit Reset register (last register, and the rest looks like the same address offsets)

   Interesting! I also took a quick look at the reference manual (mostly just the table of contents and a few glances at some register maps), and it looks like F0 is a mash-up of F1 value line (note the presence of TIM15-TIM17) and F2/F4 (SYSCFG instead of AFIO, e.g.).

   The other peripherals you mention are intriguing as well.

   Thanks to Anton Eltchaninov, we've got value line support in the libmaple development branch, which will be merged as part of the next release. This helps keep us honest on F1 -- no more inappropriate "performance-line-isms", or the library doesn't build ;) -- and, combined with F2 support, will also hopefully make adding F0 easier than it otherwise would be. Sounds like an interesting project for an enterprising hacker once libmaple v0.0.13 is out!

   Posted 3 years ago #
6. 

   crenn
   Moderator

   Is libmaple going to be an 'extension library' for Wiring IDE? Or will libmaple v0.0.13 going to be a standalone IDE as per the other releases?

   Posted 3 years ago #
7. 

   mbolivar
   LeafLabs

   Good question. There's too much work to do to integrate libmaple within Wiring for the next release (the APIs are still incompatible, and while some progress has been made on that front, there's a lot that still needs to be sorted out with the Wiring team), so we'll do another standalone release to get the code out there before moving on.

   Edit: Also note that we will definitely keep developing libmaple separately, in its own tree. We don't foresee a single AVR/STM32 Git repository anytime in the foreseeable future, as that doesn't leave us with enough flexibility to make our own decisions quickly.

   Posted 3 years ago #
8. 

   crenn
   Moderator

   Lastly, is leaflabs interested in using the new WireBase library instead of the old Wire library that's currently available in the MapleIDE? I know there is still improvements to be made, but thought you guys might be interested as Hardware I2C support is now a lot simpler than the previous Wire library I wrote.

   Posted 3 years ago #
9. 

   mbolivar
   LeafLabs

   Yes, definitely. Send us a patch?

   Posted 3 years ago #
10. 

    crenn
    Moderator

    What do you mean by patch? A pull request on github or an email? I'll send an email later tonight either way.

    Posted 3 years ago #
11. 

    mbolivar
    LeafLabs

    either one is fine: http://leaflabs.com/docs/libmaple/contributing.html

    Posted 3 years ago #
12. 

    mbolivar
    LeafLabs

    Back on topic:

    The STM32F0Discovery at Future Electronics is listed at $7.99 . So that is probably the lowest-cost SWD ST-LINK/V2 at the moment :-)

    Sold out here :(. Sigh.

    Posted 3 years ago #
13. 

    gbulmer
    Moderator

    Sold out here :(. Sigh.

    Sorry about that. I did buy several, but there were some left when I posted.

    Farnell in the UK have plenty:
    http://uk.farnell.com/stmicroelectronics/stm32f0discovery/eval-board-cortex-m0-stm32f0/dp/2096251?Ntt=stm32f0discovery
    RS have them too:
    http://uk.rs-online.com/web/p/microcontroller-processor/7587554/
    so I imagine there will be more turning up at Future.

    For USA residents, Digikey appear to have some:
    http://www.digikey.com/product-search/en?x=0&y=0&lang=en&site=us&KeyWords=32f0discovery
    and Mouser have some on order
    http://www2.mouser.com/ProductDetail/STMicroelectronics/STM32F0DISCOVERY/?qs=y%252bFWVGuMvwZK8miFvhZefg%3d%3d

    It is good value for a USB uploader, but amazing value for a hardware serial wire debugger too!

    Posted 3 years ago #
14. 

    mbolivar
    LeafLabs

    Got one on Digikey. Sounds like a good rainy-day project.

    Update (11 June 2012): And it's here!

    Posted 3 years ago #
15. 

    gbulmer
    Moderator

    I forgot to mention two differences between STM32F0 and other development boards and ICs in the ST Micro family.

    The STM32F0Discovery board is 2x33 pins. This is great because the pins are single rows, but ...
    My favourite breadboards are only 30pin-rows long, and another other popular type are only 28pin-rows, so folks might need to get longer breadboards.

    The STM32F051 is *NOT* pin compatible with STM32F1xx or STM32F2/4.
    The STM32F051 has more I/O pins than the STM32F1/2/4. The STM32F051 I/O replaces power/ground pins of the STM32F1/2/4. The 48pin STM32F051 has two more I/O pins (hence 2 less power/ground) and the 64pin part has 4 more I/O (hence 4 less power/ground).

    It might be worth noting, the STM32F050 is even simpler than the STM32F051 on the STM32F0Discovery board. So the STM32F050 should be even lower-cost! (I've seen prices, which are lower, but I haven't found any in stock, so the prices might not be reliable.) On paper, the STM32F050 is more powerful than an Arduino UNO's ATmega328; faster, more RAM, better ADC, more and better timers, DMA.

    The STM32F051's do look like great parts for low-cost robots.

    Posted 3 years ago #

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