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Pin assignments — STM32WL

4 VARIANTS · SIGNAL NAME · GPIO · SOURCE LINE

Which pin of the STM32WL connects to what, per variant in the firmware repo. This is a reference page for anyone who builds, measures or wants to understand a board — which device you can buy is in Node matrix, and what sits inside the chip per family is in The four platform families.

Note

Source. MeshCore v1.17.1, commit d929643, 14 August 2026 — variants/*/platformio.ini and the headers in the same directory. Reproduce with tools/variant-pins.py:

python3 tools/variant-pins.py --repo ../MeshCore \
    --familie STM32WL --markdown --taal en --kopniveau 3

Commented-out lines do not count. A #define inside #if 0 does: the script cannot tell the difference.

How to read these tables

Per variant the signals are grouped: LoRa radio, I2C, SPI, display, GPS, buttons and LED, power and battery, and whatever falls outside that. Each line names the file and line number where the definition sits, so you can check it yourself.

The value is sometimes not a number but another name — P_LORA_NSS then points at LORA_CS, which sits a few lines up with the real number. The first occurrence wins: if a name appears twice, the second is an alias.

Constants that look like a pin but are not do not appear in the table. LORA_TX_POWER, SX126X_DIO3_TCXO_VOLTAGE and BLE_PIN_CODE are radio and firmware settings; the script reports them separately.

The four STM32WL variants have the shortest tables of any family: 15 signals from the build_flags and 2 from a header. The radio sits on the die, so there is no SPI link to a separate transceiver eating pins.

The variants

rak3x72

Power and battery

Signal Value Source
PIN_VBAT_READ A0 target.h l.11

tiny_relay

Power and battery

Signal Value Source
PIN_VBAT_READ A0 target.h l.11

wio-e5-dev

Other

Signal Value Source
PIN_SERIAL_RX PB7 platformio.ini l.12
PIN_SERIAL_TX PB6 platformio.ini l.13

wio-e5-mini

LoRa radio

Signal Value Source
P_LORA_TX_LED LED_RED platformio.ini l.12

Buttons and LED

Signal Value Source
PIN_USER_BTN USER_BTN platformio.ini l.13

Sources

  • variants/ — 4 directories of this family, each with a platformio.ini and the headers beside it
  • tools/variant-pins.py — the script that builds these tables

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