Son Hai Nguyen

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9 years, 1 month ago.

stm32 with mbed without dev-board

Hello,

I would love to use mbed, but do not want use my dev-board nucleo f303re in release of my project. I want everything on one PCB, not wired to another PCB. I only found this https://developer.mbed.org/cookbook/Reference-Design , but it contains only schematic of LPC1768, but I need schematic to nucleo f303re, to be able to assemble it in another PCB. Now I actually have no idea, how to get working standalone stm32 chip with mbed.

Thanks in advance

1 Answer

Erik -
9 years, 1 month ago.

You don't need anything to have it work with mbed, except the normal things you need for an MCU. So you need something to program it (The ST-Link part of the nucleo board can do this, but you can use also another programmer or a bootloader (no idea which bootloaders STM32s have built-in)), you need to supply a clock (otherwise it will automatically switch to the internal clock, but someone screwed up, and now there is a 10 second wait after reset before it does this), and power supply obviously. Mbed does not need anything special, it is just a binary running on an MCU.

Accepted Answer

I tried to run compiled binary, I managed to flash it into MCU, but it did not do anything (I flashed simple blink program, which worked on dev-board). But I did not used external clock.

posted by Son Hai Nguyen 24 Sep 2015

It should as far as I know currently wait 10 seconds before it picks the correct clock, but then it should work. Mbed binaries are just like any other binary. You do have a Nucleo F303 where it does work on?

posted by Erik - 24 Sep 2015

Not sure about this, there is a feed from the ST-LINK chip (MCO) to the OSC_IN, is the set up using this as clock input rather than IRC? Perhaps fit the 8MHz crystal and loading capacitors and try again. Set up should pick it up with that delay. Make sure all the VSS (ground) and VDD (+3.3v) power lines are connected and decoupled as per the schematic. see fig 26:

http://www.st.com/st-web-ui/static/active/en/resource/technical/document/user_manual/DM00105823.pdf

I think boot0 must be grounded also.

posted by Paul Staron 24 Sep 2015