STMicro Enters Arduino Market--Cortex M4 boards for less than $11

Well powerful is a relative term. These look like about 15% the power of a Raspberry Pi. And the Raspeberry Pi is about a quarter of the Beaglebone Black. But these M4 boards are cheap.

$10 for the M4 board. $45 for the Beaglebone Black.

About 25x the speed for 4.5x the price if you compare these ST boards to the made in USA Beaglebone Black.

Well some would argue is Texas is in the USA.

It's not all about CPU throughput, these are for embedded use, not general computation. A STM32 can toggle a PIO at 80MHz. (Depending on clock speed, those ones are more like 42MHz - 1/2 the CPU clock in general).

ST pioneered the ultra-low-cost dev board concept AFAICT, with their Discovery boards. Very handy for development and can also be used as JTAG/SWD adapters for your own boards.

--

John Devereux

Be careful with that; the STM32F2 and F4 have a serious ADC problem making them unusable in some applications (mine...). Basically they pickup noise spikes from the flash accesses. Check the errata for the actual device.

I don't know if it is fixed in newer silicon like the F3.

It may be OK if you can do averaging or other processing like removing outliers, as they suggest. I was doing pulse detection and getting huge noise glitches.

The ADC would theoretically be very powerful, ~2MSPS per ADC and you can interleave the 3 ADCs to get 6MSPS.

Oh and you can't connect the reference to anything other than Vdd either.

--

John Devereux

Neither does mine now... :)

I found that too, unbeatable at that performance point.

Yes, I had a guy from ST visit re the issues I had.

The STM32 parts are very well supported in the openocd JTAG debug host, if that is important to anyone (it was to me).

--

John Devereux

Talk a little about IDEs and development environments? One of the successes of the Arduino is that it's an ecosystem, with the same IDE on many platforms, and 3rd party support, both for hardware and software.

Same thing for the Pi -- a large developer community.

(But for $10, well worth looking at!)

>

Every processor board seems to have their particular strengths. The Raspberry has no ADC, but has a high speed parallel bus for interfacing to a camera, enough memory to store the images, and it runs Linux. Also: USB, wi-fi, RT HDMI video, keyboard, sound, ...a different animal.

I'm not surprised they are having noise problems with the ADC - a linear circuit like an ADC is like playing cards on a river raft. :) The noise tolerance of digital circuits is enormous.

For quick and dirty prototypes, don't forget the $3 Picaxe. These things are programmed in Basic with full documentation online. They have the features of the underlying Microchip, including ADC, PWM, I2C, IR, etc. They are probably

10X easier to program than the Cortex board mentioned here. The nucleo people claim you can be up and running in minutes, but I don't believe it.

I have been the pre-compiler and pre-assembler for many chips, so am very leery of claims. If I had another life span, I would invent AI-based languages for chips, since 90% of the use cases are done in 10% of the code space.

Just my 2 cents.

JB

I don't know...66 GPIO pins sounds like a lot of I/O.

I've only done signal processing on mine, which is why the Raspberry Pi is a non-starter. You can't do much with it and not hit the CPU wall.

Well, I have been doing feature extraction type things. What do you do in practical terms that needs the MIPS?

I have a pic24fj128gc010 dev board - that does ADC at 10 MSPS. But I tried to compile the C program it came with, and it did not compile - I still plan to get it going, but a toe in the quick sand is enough for me.

So if you are doing many MIPS, then what are you doing for the software development side of things? A DSP chip may be in order. You have to look at the whole enchilada with SW development, and the Pi running Linux means a huge number of SW tools. I was considering the Beaglebone, until an amateur astronomer type told me it was lousy from a SW POV, that he had spent months dealing with bad drivers and what not.

As the Danish saying goes, "A stranded boat on a shore is a light house for all."

Be interested to know what you have been using, or have selected.

take care, JB

Nothing has the user base of RPi or Arduino. I think that the Beaglebone issues have been mitigated. I have two. At one point an OS update broke HDMI compatibility with the Motorola Lapdock, one of the most popular consoles for the RPi and BBB.

Which OS for the BBB? It must run half a dozen. The default Angstrom is fine if you don't mind learning the nuances of another OS. [It is mostly debian, but not strictly.] You can even run two microkernel linux OSs on the BBB.

I just use the microHDMI or SSH into the BBB. I never even heard of the Lapdock. Now that I looked one up, I'm not sure I would ever buy one.