I met one of the people working on this "mchck" device a few weeks back, they are thinking of moving from a Nuvoton Cortex-M0 to an STM32 Cortex-M3 @32MHz. I love this form factor, and the layout looks simpler than a Maple Mini for adapting/extending, though I don't think they've gone through any iterations and i'm skeptical about what the ADC performance will look like:
mchck: $7 Cortex-M0 board
(48 posts) (12 voices)-
Posted 3 years ago #
-
Those through holes along the side are NOT lined up. It's making me anxious :) Is there a reason for it???
The silk screen isn't labeled.... so that's part of how they're using so little space... that's a trade-off...
I think it needs at least 1-2 mounting holes, at the very least so it can be covered with a protective case.
Posted 3 years ago # -
gbulmer
Moderatoranton -
Unfortunately the cheapest stm32 chip with USB costs about 5$ itself.
I had a quick look at Future Electronics, and the cheapest 48pin STM32F103 (with USB) is $2.45 (USD):
http://www.futureelectronics.com/en/technologies/semiconductors/microcontrollers/32-bit/Pages/5768411-STM32F103C6T6A.aspx?IM=0
So $7 (USD) should be okay.DIYDSP -
Those through holes along the side are NOT lined up. It's making me anxious :) Is there a reason for it???
If you read the comment on the picture https://github.com/corecode/mchck/wiki/images/mchck-features.jpg, or the bullet point which says
in case your OCD is twitching because of the not neatly lined up (i.e. staggered) headers: this is a SparkFun trick to allow easy soldering of the pins
They give a link to an explanation.
They label those headers with the phrase "Sparkfun locked headers"
I happen to know what that is, but I googled for "sparkfun locked headers", it returns:
http://www.sparkfun.com/tutorials/114
which is the link they provide.Sparkfun explains that after a lot of experimentation, Sparkfun are using a sneaky technique to make it easier to solder header pins into PCBs. The idea is to slightly staggers the holes for header pins. The effect is to hold the pins in place while the header is being soldered into a board.
Posted 3 years ago # -
gbulmer
Moderatorsiy - I like the slightly smaller 0.9mm drill too. That is partly because students try the 1mm and bigger first, and they all get broken:-)
I am sufficiently bad at hand-drilling holes, that I may have discovered the 'sneakey' staggered hole technique purely by accident :-)Posted 3 years ago # -
siy
Membergbulmer, I think that Maple Mini should fit into $7 margin, at least when produced in quantities. MCU is little bit expensive for this margin in retail (minimal price is $6.20 in local stores), but wholesale prices is about $3.5 and at e-bay 10 MCUs can be purchased for about $4.5 each. This leaves enough room for remaining parts, I think.
By the way, at weekend I've prepared 0.6" version of Mini48. Initial version was assembled and tested, but I've already prepared significantly improved design. Once it will be assembled and tested, I'll submit it into repo. I'm not going to replace initial Mini48 design with new one mainly because 0.6" version is much more complex for manual assembling. The board still uses 0.15mm pitch, but passive components are 0402...
Posted 3 years ago # -
gbulmer
Moderatortochinet - would you explain what you are aiming to do, and we might be able to help. What platform are you using?
If you are interested in hardware debugging, my default advice is to get one of ST Micro's boards with on-board ST-LINK/V2 which are very low-cost. For example the STM32F4-DISCOVERY is 1/2 the price of an Arduino. An ST Micro ST-LINK/V2 provides both JTAG and Serial Wire Debug (SWD) for STM32, and it costs less than an Arduino.
I am using gdb on a Mac. I intend to try Eclipse & NetBeans this weekend.
Posted 3 years ago # -
BruceF
Membergbulmer - Are you using an ST-LINK to talk to STM32 from your Mac? What software are you using that can successfully talk to it? OpenOCD has early support for ST-LINK in git, but that's the only non-commercial Mac ST-LINK support I've seen. Is there something I've missed?
Posted 3 years ago # -
siy
Member@BruceF, I've posted following link in forum some time ago in other thread: https://github.com/texane/stlink
It works just fine for me with STLINK/V2.P.S. I've no relation to that project
Posted 3 years ago # -
gbulmer
ModeratorBruceF - There are three Open Source programs (I know of) which drive ST-LINK and ST-LINK/V2.
The one I also recommend is https://github.com/texane/stlink.That has a command line interface, with both an upload and gdb server.
The gdb server supports source-level debugging, breakpoints, single stepping etc.Another upload which has a Qt based GUI is http://code.google.com/p/qstlink2
The third one is http://code.google.com/p/arm-utilities
Currently that doesn't support STM32F4 erase & programming.
I started to implement STM32F4 (did erase), but I'm now using texane/stlinkPosted 3 years ago # -
The above board looks like it would be a good candidate for Jared Boone's preliminary port to the nuc120.
https://github.com/sharebrained/libmaple, I kind of like the nuvotons pricewise...Posted 3 years ago # -
gbulmer
Moderatorfeurig
I kind of like the nuvotons pricewise...
Where do you buy them?
I only found Digikey and Arrow sell them.
The prices at Digikey:
http://search.digikey.com/uk/en/cat/integrated-circuits-ics/embedded-microcontrollers/2556109?k=nuc120for a NUC120LE3AN, 128K flash, 16K RAM, 50MHz, 48pin LQFP is $4.71 one-off
($2.89680 25-off)The price for a STM32F103CBT6 128K flash, 20K RAM, 72MHz, 48pin LWFP is $4.75
($3.89600 25-off)
http://search.digikey.com/uk/en/products/STM32F103CBT6/497-6288-ND/1754420So it looks like it needs reasonable quantities before the price is significantly different. Maybe you buy in those quantities, or have a lower-cost source?
The thing that caught my eye about the NUC120 is 5V operation. That might make an Arduino shield compatible board much easier to make.
Posted 3 years ago #
Reply »
You must log in to post.