On-board is a STM32F407VGT6 microcontroller. On Board is an ST-LINK/V2 embedded debug tool, two ST MEMS, digital accelerometer and digital microphone, one audio DAC with integrated class D speaker driver, LEDs and push buttons and an USB OTG micro-AB connector. By removing two jumpers ST-LINK could be used to program external microcontroller.
ST-Link V2 is intended for debuging the on-board microcontroller or as debug interface for any external ST cortex MCU. I have ULINK2 Debug Adapter. and I wanted to connect discovery board to ST32F4 MCU. Unfortunately there’s no direct debug connection to DISCOVERY board, which could allow using external debugging interfaces. Here’s how it can be done:
Take STM32F4-DISCOVERY board and turn it upside down. There are several jumpers (solder bridges) marked with SBxxx. Remove SB5 and SB9. This will disconnect ST/LINK output signals from main MCU avoiding colision with ULINK2 signals:
Next, solder tiny wires to open solder bridges. Each solder bridge has arrow shape. Connect wires at proper side of the jumpers and to pads, as indicated in this diagram:
Next, solder breadboard with 20 pin header to discovery board and connect wires to proper pins as indicated above. Take care about IDC pin numbering (zig-zag)!
Connect ULINK-2, run uVision, open your favorite STM32F400 project and check the debug window:
And finally, snapshot with webcam (I was holding my DELL above the desk):
