Stk-l21 Isp Pinout · Fully Tested

If SWD is unavailable, you can use the built-in UART bootloader if the STM32L0 variant supports it:

| Signal | Point Label | Point Description | Color Code (Wire) | |--------|-------------|-------------------|--------------------| | | TP-GND | Large copper area near screw hole | Black | | VCC | TP-VCC (3.3V) | Small pad near capacitor C1170 | Red (Do not connect!) | | CLK | TP-CLK4 | Test point just above the eMMC | White (CLK) | | CMD | TP-CMD | Test point to the right of eMMC | Green (CMD) | | DAT0 | TP-DAT0 | Test point adjacent to CMD | Yellow (DAT0) |

To establish a successful ISP connection for the STK-L21, six primary points must be soldered to an ISP adapter: DATA0 (D0):