LOUP Engineering: Hardware Bring-Up · advanced
Pin Maps Belong in the Bring-Up Evidence
One wrong GPIO can imitate a codec, driver or clocking failure.
The lab result behind Pin Maps Belong in the Bring-Up Evidence changed the implementation more than the first hypothesis did. The Minewing V16 mapping uses MCLK 13, BCLK 14, LRCK 47, DIN 21, DOUT 48, I2C SDA 41, SCL 42, MIC_MUTE 39 and AMP_EN 17.
Those values are not trivia when bringing up a board. They define whether clocks reach the codecs, whether capture and playback directions are reversed, and whether mute or amplifier control is unintentionally asserted. Keeping the mapping in reviewed firmware documentation made hardware/firmware mismatches easier to isolate.
Reversibility stayed part of the experiment: preserve the previous artifact, make the change, then prove the new path before promoting it. Evidence marker: minewing-v16-pins.
A pin map is part of the hardware-software contract and should be versioned with the board revision it describes. Preserving that distinction is what lets the project increase complexity without losing the ability to explain a regression.
Project evidence
LOUP engineering marker: minewing-v16-pins. This note records the design or debugging lesson without publishing device credentials, private keys, customer data or manufacturing secrets.