ST discovery card pins 1 AIN-1 2 JTCK 3 GND 4 JTMS 5 NRST 6 SWO MM misc connector 1 GND 2 reset_n 3 boot0 4 tx1 5 rx1 6 +3.3V 7 GND 8 jtms 9 jtck 10 jtdi 11 jtdo 12 jntrst 13 sda2 14 scl2 15 pe1 16 pe0 For debugging: ST MM JTCK 2 9 GND 3 7 JTMS 4 8 NRST 5 2 TL debug connector: TL ST GND 1 3 NRST 2 5 SWDIO 3 4 SWCLK 4 2 MegaAccel: Jumpers PC0 (pin15) (blue) PE0 (pin97) accel_ref (debug 16) PC1 (pin16) (green) PE1 (pin98) accel (debug 15)