To add to what Sailoog wrote:
With the new Seatalk wiring, the signal that the Raspberry Pi sees can be squared up by adding a resistor between pin 38 (GPIO 20) and pin 39 (GND) of the 40-pin header*. Any resistor value between 1K and 10K should work, with lower values making for a sharper transition between 1's and 0's. See https://pinout.xyz/# for a reference of the pin numbering.
This patch adds a resistor in parallel to resistor R21 (R2 in the schematic at the start of this thread), reducing the total value of the pull-down resistor. For a tidier fix, those experienced with SMD soldering can piggy-back a 0603 sized resistor on top of R21.
With the new Seatalk wiring, the signal that the Raspberry Pi sees can be squared up by adding a resistor between pin 38 (GPIO 20) and pin 39 (GND) of the 40-pin header*. Any resistor value between 1K and 10K should work, with lower values making for a sharper transition between 1's and 0's. See https://pinout.xyz/# for a reference of the pin numbering.
This patch adds a resistor in parallel to resistor R21 (R2 in the schematic at the start of this thread), reducing the total value of the pull-down resistor. For a tidier fix, those experienced with SMD soldering can piggy-back a 0603 sized resistor on top of R21.