Post your PCB

[Badger]

That sounds like a nice idea, and not too hard to design either. Seeing as it would be a base board for the F4 Discovery there would be a lot of room for various devices, not all need be populated, e.g adding footprint for an i2c sensor, SD card (perhaps both SDIO and spi?). Recently I've been getting my PCBs manufactured by the Dorkbot group order; it works out very cheap (normally < $20 total including international postage for 3 boards), all you do is email them an eagle .brd and it only takes a few weeks. So prototyping something like this needn't be expensive

[barthess]

Hmm, it is very hard to create not too expensive board with all staff STM32F4 supported, it will huge monster on multilayer pcb. More optimal way (in my opinion) is quick start with standard discovery board and create your own specialized board later.

[noether]

I agree, Discovery is a good starting point, you can always connect the micro to other peripherals with wires in an easy way. It is a really cheap board with a programmer onboard.

One thing that I always miss in every affordable ST evaluation board is what Badger has said, there is not the SDIO interface to the SD card.

By the way Badger, is there any special consideration more designing a board for this micro? any lesson learned? Like grounding the clocks, but in my opinion this is always a must in every design xD.

Cheers

[Badger]

I've had a few problems with the STM32 chips, but generally they're pretty easy to design for. One problem is that the documentation can be hard to find, and various important bits are hidden away. For example, my first design remapped an I2C port, and it wasn't until I'd built it that I realised there was a hardware bug with the chips that meant I couldn't use SPI and the remapped I2C at the same time (thankfully Giovanni pointed out the eratta and saved me hours of headaches). I'm still having problems with the clock on my F4 board, I'm trying to use a ABM3B as it has a nice small footprint but it seems really unstable, even after I grounded the the ground pins. Probably my problems stem from lack of understanding of whether or not it has capacitors and series resistors built in (I also have these on my PCB, which could be causing problems), but I think I will swap to a bigger crystal like the one on the F4 Discovery and most other STM32 boards, as it seems to make all my problems go away

One thing that confused me with the new F4 chips is that they have a circle marker in two corners...

[barthess]

maybe if you are interested we can be in contact as we are going (it seems) to use the same RTOS for the same application .

I can post EAGLE project files somewhere. But I embarrassed to post source code because it too dirty, all comments written in Russian and contains a lot of foul language.
What software you use for displaying telemetry on ground station?

[Badger]

I should probably also point out that one of my intended uses is for an autopilot / stabilisation of flying things. So it seems we have several users with common goals. The board I've designed uses an RFM22B radio link which is the same one as used in OpenLRS. It should have a fairly good range..

I have an STM32 dev board with a nice big LCD on it which I intend to use for showing telemetry, if I ever get around to writing a driver for it

[barthess]

I have an STM32 dev board with a nice big LCD on it which I intend to use for showing telemetry

Beautiful board. I have only LCD display from chinese Nokia clone and do not know where to find pinout for it.
P.S. MicroSD slot on my board desoldered from that phone.

[barthess]

Predecessor of my current autopilot board installed on "Mad Max car".

[barthess]

Hi all. I want to up this topic with some my chibios related boards. I like to watch your custom PCBs, hope you too.

http://imgur.com/LYHSMwc
My current FSMC dev. board. It is some 4-layer automotive board. It do nothing except of UART routing but has tons of unneeded stuff just to be more "enterprise".

http://imgur.com/aY4eV7m
http://imgur.com/g5UooRS
My next iteration of autopilot/toy board. Hardware bugs included.

http://imgur.com/6VrhnXp
http://imgur.com/ibHPOtU
My handcrafted STLink v2. It has some bugs too. I made it just because I can.

[ErikZalm]

This is a board I designed.
It is running ChibiOS 3.0

https://raw.githubusercontent.com/ErikZ ... ronics.jpg