1
\$\begingroup\$

Is there a way to use the TX/RX on the STM32F030 Discovery board? The User's manual says "reserved", but since the Cortex M0 doesn't have an ITM, I'm looking for another way to get data out of this board (I need to measure PWM & Duty Cycle for a bit, then prototype away)...

Does the TX/RX do anything on this board or do I have to get another USB->Serial adapter and wire it in?

\$\endgroup\$
6
  • \$\begingroup\$ @sparky256 the question is about the discovery board, not a bare chip. It has the high pin count version. \$\endgroup\$ – Chris Stratton Jul 13 '16 at 22:41
  • \$\begingroup\$ @ChrisStratton. Then we need a schematic of that board and a photo would help. Right now not much to work with. \$\endgroup\$ – user105652 Jul 13 '16 at 22:49
  • \$\begingroup\$ A schematic won't help, the question is ultimately about the firmware of the on-board STM32F103 implementing the embedded ST-Link for programming the STM32F0 target MCU. If that does not present as a composite device with a CDC/ACM interface, then the options are to find (or write) a different firmware for it that does, or to use an outboard logic-level serial converter or receiver. \$\endgroup\$ – Chris Stratton Jul 13 '16 at 22:57
  • \$\begingroup\$ @ChrisStratton. Thanks for clearing that up. This is not an off-topic issue then? \$\endgroup\$ – user105652 Jul 13 '16 at 23:03
  • \$\begingroup\$ Technically it is a development tool, so on-topic. In practice, it's a problem with a twelve dollar board that has a six dollar solution... \$\endgroup\$ – Chris Stratton Jul 13 '16 at 23:05
1
\$\begingroup\$

V2 version of the ST-Link do not provide CDC DEvice. But you can buy UART<->USB converter and connect it to the any UART on the board (eg UART1 PA9 PA10).

It is always good to have such a converter in a drawer :)

\$\endgroup\$
3
  • \$\begingroup\$ The on-board STLink implementations on the Nucleo boards generally do, while those on the Discovery series do not. However, the recommendation of the external converter is right on - several should be on hand for this problem and many others. \$\endgroup\$ – Chris Stratton Feb 4 '18 at 19:46
  • \$\begingroup\$ V2 does not, V2.1 does. \$\endgroup\$ – 0___________ Feb 4 '18 at 22:48
  • \$\begingroup\$ I moved to the Nucleo ones just to make it easy ;) \$\endgroup\$ – Thor Johnson Mar 11 '19 at 17:11
0
\$\begingroup\$

If I remember right that is correct they dont feed the rx/tx through the debugger/stlink, even if you connect the solder bridges.

The PA9 PA10 (if I remember right) are available as pins around the side you would need some 3.3v TTL uart solution (FTDI breakout).

The stm32 discoveries and nucleos are hit or miss as to whether or not the send the uart through the stlink end of the board. Wish that was consistent.

\$\endgroup\$
3
  • \$\begingroup\$ yeah, tx and rx are on the stlink side of the solder bridge so basically nothing there to see...AFAWK \$\endgroup\$ – old_timer Jul 14 '16 at 0:49
  • \$\begingroup\$ ST does provide firmware updates. And I have too many discovery and nucleo boards to count, so I dont go back through all of them. There is somewhat of a short list of ones where the serial actually works through the stlink, and have tried the solder bridges on some to see if it happened to work. \$\endgroup\$ – old_timer Jul 14 '16 at 0:50
  • \$\begingroup\$ AFAICT, the STLink/v2 firmware on Discovery boards will never get serial passthrough from ST - the bootloader itself starts USB as a non-composite STLink before running the main firmware, so there's no chance to add a USB CDC-ACM interface. On the other hand, the STLink/v2-1 firmware/bootloader on all Nucleo boards should be already have serial pass-through support or be upgradeable to a version that does. If you're willing to reflash the STLink, it's always possible to install alternative firmware that does CMSIS-DAP or GDB + CDC-ACM, but there will be no way to restore the old firmware \$\endgroup\$ – Devan Dec 11 '16 at 20:35

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.