diff --git a/doc/pinout.txt b/doc/pinout.txt
new file mode 100644
index 0000000..63f613d
--- /dev/null
+++ b/doc/pinout.txt
@@ -0,0 +1,24 @@
+PA00: ADC: U_Bat
+PA01: ADC: U_Solar
+PA02: ADC: U_SW
+PA03: ADC: I_Solar
+PA04: ADC: I_Load
+PA05: EXT_SCK
+PA06: EXT_MISO
+PA07: EXT_MOSI
+PA08: Charge pump
+PA09: EXT_SCL
+PA10: EXT_SDA
+PA11: Solar switch
+PA12: Load switch
+PA13: SWDIO
+PA14: SWCLK
+PA15: n.c.
+
+PB0: LED A
+PB1: LED B
+PB3: LED C
+PB4: n.c.
+PB5: RS485 DE
+PB6: RS485 TX
+PB7: RS485 RX