I bought mine through Nu Horizons but they have $100 minimum. Wasn't a problem in my particular case at that time. It is nice to have them at digikey. I was kind of surprised at the markup though. The LE3AN is a medium density if I recall. If you can deal with less memory the prices drop considerably.
mchck: $7 Cortex-M0 board
(48 posts) (12 voices)-
gbulmer
Moderatorfeurig - This isn't really a good alternative to normal USB, but it is an interesting "thought experiment" ...
The STM32F0Discovery does have USB ST-LINK.
At least one of the commercial IDE vendors has a debug library that an STM32F program can use to write output via the ST-LINK to the host. AFAIK it isn't very high-performance, because it has to execute a debug exception after each byte (or couple of bytes), and then wait for the host program to retrieve the bytes, and restart the program. I think a reverse mechanism, reading bytes from the host, is doable (I don't think input was supported in the debug library).
I'd rather use a cheap USB-UART, but somebody might want to get more value from an STM32F0Discovery :-)
These looking interesting: http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=FRDM-KL25Z
They are about double the price of the mchck. The biggest problem for me is the software download comes in a .exe file. Not helpful for Mac, or Linux, or BSD, or ... users.Posted 3 years ago # -
The nuc120s come with usb standard but like everyones arm you pretty much have to scratch build though if I had more time I would flesh out Jared's libmaple port. (only thing missing is a boot loader).
I am working on getting the stlink figured out for debugging but am happy to use the built in serial code loader also I am interested in getting the non usb f1s and the f0s to run libmaple as I migrate along.
The current docs on the mchck talk about the freescale m4 but the prototype pictures are of a nuc120. fwiw the teensy3.0 uses both nuvoton and freescale.
Ironically we were just discussing the LK25Z on the dorkbotpdx mailing list (and what a POS the firmware on it was)
Posted 3 years ago # -
gbulmer
Moderatorfeurig - Thanks for the tip about the KL25Z. Any manufacturer who actively makes things hard for non-Windoze users goes low on my list of interests, but your comment takes them off my list. Big pity, it is cheap.
I have (at least) three projects ahead of STM32F051. I'd likely use a CP2102 board for USB-USART, as suggested by tormod, though lots of schools have a USB to USART cable sold for use with PICAXE that I could use instead. Those CP2102 are very cheap, and on something small like a micromouse, removing the weight and space of a separate USB-USART is an okay thing to do.
The Teensy3 looks fun, but the board has no silkscreen in the pictures, and their isn't a link to a toolchain and libraries at pjrc.com
I've emailed Paul Stoffregen to get some more information. I notice the Teensy3 has a second IC, so I wonder if its a USB upload, or a full hardware debugger? Paul Stoffregen seems to be talented enough to write his own SWD debugger.The Nuvoton chips look interesting, but my usual suppliers don't stock them, even Digikey don't have prices. So they seem like too much hard work for me.
I assume you have tried https://github.com/texane/stlink to drive an ST-LINK via gdb?
I haven't used the most recent version. (IMHO they 'lost the plot' when they "improved" the build by requiring a program be downloaded and installed to find where lubusb is installed, I know where libusb is installed!! )
But the gdb server did work okay, with single step, break point, etc. working from gdb. Upload worked too.Posted 3 years ago # -
mconners
MemberI have one of those KL25Z freedom boards and for $10-$15 it's not a bad little board. I do all of my development in linux. I did need to get a win machine for 5 minutes to update to the latest bootloader, but after that it has worked ok for me. I'm actually enjoying it quite a bit. Even though the sample code is in .exe format, it is just a executable zip and package manager or unzip on linux can handle it just fine.
I downloaded the Code Red Red Suite, which according to the freescale website is free as long as you are developing for the freedom board, and it came with several samples, including the source to the demo software that exercises the entire board. And it's well split out so you can see the I2C library, the touch slider library, the gpio/led flashing library, etc ...
Honestly I've enjoyed working with it, I plan on spending sometime this weekend porting some of my maple projects over to it just for fun.
Mike
Posted 3 years ago # -
I think if they are going to call it the "Freedom" board the chips should be fabbed in the states.
I think Microchip is the only major manufacture with enough Defense contracts to bother to do that.But they don't do arm.
Bummer is that STM only recently moved this stuff to asia.
Posted 3 years ago # -
Gbulmer: The harshest critique of the KLZ came from someone who is a huge fan of freescale in general and spent a lot of time with the coldfire and the hcs08 series of chips (which are also contenders with through-hole cheap usb). He managed to foobar his board by just plugging it into a mac. The bootloader choked on the stuff that macs like to put on all of their file systems. Then he started looking at the rest of the codebase. I thought this was a dramatic improvement from the JM-badge that used the same bootloader scheme. It actually crashed the mac. 4 years later they get better.
Also have you looked at the mcp2200?
Posted 3 years ago # -
mconners
MemberOh believe me, not a fanboi, just satisfied with the money spent. I gave them some crap on the Element 14 forums about calling it a Freedom board when they were tying me to windows. They have since updated the bootloader to support Linux. Not saying I had anything to do with it, but they did move in a satisfactory direction. I happened to stumble across the Code Red tools and found they worked fine for the KL25Z. I also just got a couple of the LPCExpresso boards for under $20 each. I am just getting underway with those.
I am impressed with one thing, the number of ARM based development boards really seems to have exploded in the last few years and they are getting cheap. I didn't find this much availability when I bought my ret6 board when they were available.
Mike
Posted 3 years ago # -
gbulmer
Moderatormconners - Have you looked at the STM32F4Discovery, STM32F0Discovery, or STM32F3Discovery boards?
They are a similar price to the KL25Z, have STM32F4 (168MHz Cortex-M4 1MB Flash), STM32F051, and STM32F3 (72MHz Cortex-M4 256KB Flash) MCU's, and hardware JTAG/SWD debugger in the price. Keil's free (restricted) IDE works on the STM32F4.feurig - mcp2200 is new to me. Thank you.
Being a Brit, I am more likely to use the newer, cheaper FTDI's than a Microchip part ;-)Posted 3 years ago # -
gbulmer
Moderatorfeurig - MCP2200 - Interesting!
Have you tried using the GP I/O pins, for example to hold BOOT0 and BOOT1 while flicking nRESET?
Has anyone used those GP I/O pins from Linux/Mac or is it Windows only?Edit: found this: http://www.microchip.com/forums/m537651.aspx
which says it works on Linux, but not Mac (at 10.6.5).
They say the MCP2200 is a "CDC composite device with IAD" which the Mac doesn't accept.Posted 3 years ago # -
Actually the bastards at apple implemented the IAD (after years of hounding) on Snow Leopard and beyond. (intel only). So technically it is supported as long as you are willing to go 64 bit intel.
The mcp2200 is as good as the cp2102 and the underlying cpu is a pic18f14k50 So you get the best of both worlds.
I have the code started for getting the code loaded onto the through hole lpc1114 which is pretty much the same deal (two pins to pick what happens on reset) but I am not finding myself with a ton of extra time. Once this code is done I will turn the same onto the stm32.
Posted 3 years ago #
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