Receive and send data with STM32L100RC

[electronicsbasickid]

Hi,

I'm using a STM32L100RC discovery board and I'm trying to send/receive two words (string type) to/from another program not related to the MCU. Nevertheless, the Virtual Com Port (VCP) is not available on this device. Is it still possible to use the functions CDC_Transmit_FS(...,...) and CDC_Receive_FS(...,...) ? Or is there another type of solution ?

Thank you in advance for your help,

Jay.

[TDK]

What's weird here is I can't find any evidence that ST actually builds this board on their site. It's not in CubeMX either. Maybe Keil commissioned it or something. Perhaps @Community member​ knows.

Keil has a page:

https://www.keil.com/boards2/stmicroelectronics/stm32l100c_discovery/

And a link to ST that comes up empty:

https://www.st.com/en/evaluation-tools/32l100cdiscovery.html

This board has an ST-Link/V2 which doesn't have the VCP interface. It may be possible to upgrade the firmware such that it does have it. The schematic shows it has the wiring in place, although you'll need to close some solder bridges.

Note:

https://www.st.com/resource/en/technical_note/dm00290229-overview-of-stlink-derivatives-stmicroelectronics.pdf

You can't use CDC_Transmit_FS/CDC_Receive_FS because these communicate with the chip and the only USB port is connected to the ST-Link. There isn't a USB connector connected to the STM32L100RC.

[Tesla DeLorean]

It's quite old, still available at Mouser

https://www.mouser.com/datasheet/2/389/32l100cdiscovery-1848009.pdf

One could connect a FTDI/SiLabs USB CMOS Serial dongle..

Supports USB, so should be able to implement a CDC Device, I'd suppose it is quite similar to the L15x devices

https://www.st.com/resource/en/datasheet/stm32l100rc.pdf

[electronicsbasickid]

The USB is actually detected as Serial dongle by the PC. I was thinking about using the "Custom USB HID" as I can't buy or add anything more for this project.