This blinky example works on any rhomb.io STM32L476 master module plugged on any rhomb.io carrier board like Deimos, Halley, Helios, Phobos, Hydra…
Rhomb.io STM32L476 module has one LED on board connected to pin PC7 through a mosfet. This pin PC7 can also be used as PWM0 output.
By following below steps we will have said LED blinking: 

Required Hardware

  • STM32L476 Master module
  • DAPter module (DAPLink interface)
  • Carrier board (Deimos, Halley, Helios, Phobos or Hydra…)

Setting up the hardware

DAPter module must be plugged on carrier board (Deimos on this example) while STM32L476 module must be plugged on top of DAPter board

  • There is a small white triangle on the upper-left corner of any socket on every rhomb.io carrier board
  • There is a small white triangle on the upper-left corner of any rhomb.io module
  • Take your Deimos carrier board upside up and look for the small white triangle located on the upper-left corner of Master module socket
  • Take your DAPter board and look for its small white triangle, now plug it on top of Deimos board firmly
  • Do the same with STM32L476 Master module and plug it on top of DAPter board
  • Make sure all two modules have been plugged firmly and properly

You are now ready to connect your rhomb.io carrier board to a PC. Take a USB cable and plug it on both the PC and the Deimos’ USB connector, the DAPLink interface should be detected by the computer as both Mass Storage Device, MSD, and Serial Port (COM/tty)

  1. Plug STM32L476 on a rhomb.io carrier board (like Deimos, Halley, Helios, Phobos or Hydra…)
  2. S
  3. Setting up software
  4. Take a USB cable and plug it on both the PC and the Deimos’ USB connector, The kit should be detected by the computer as both Mass Storage Device, MSD, and Serial Port (COM/tty)

  1. Open a File Explorer and look for the content of your kit on it. The kit will be listed as “DAPLINK”. Two files will be found inside DAPLINK device: DETAILS.txt and MBED.html

  1. Double click on MBED.html file will lead to RHOMBIO_L476DMW1K page on mbed.com website

  1. Now go to Example applications and click on “Import Program

  1. Log in into your mbed online compiler with your mbed account details if not logged in yet

  1. Import the example-blinky into your program workspace by clicking on “Import” button

  1. Once imported into your program workspace you can change LED blinking time by modifying “SLEEP TIME” in line number 11 of main.c file

  1. Now it is time to compile your code. Click on the “Compile” button located on Mbed toolbar. A .bin file will be generated. You can either save it to hard disk and then to Drag&Drop it to DAPLink device or directly save it to DAPLink device.

  1. Once the file has been copied/saved into DAPLink device the LED will start blinking. Actually there are two LEDs available: one on Deimos carrier board and one on STM32 MCU module, both being controlled by the same MCU pin so both LEDs will be blinking at the same time.

  1. The mbed-os-example-blinky code not only makes the LEDs blink but it also prints some MCU info out through serial port. Open a serial terminal and select the proper COM/tty port at 9600 bauds. You can check which is the COM/tty port assigned to your kit by opening Device Manager/lsusb and looking for “mbed Serial Port” device listed in “Ports (COM & LPT)” category