Wrong LipSync Interface Cable or damaged STEMMA QT Cable can cause Generic Error lights

[jakemcivor]

Situation 1

• Correct LipSync Interface Cable
• STEMMA QT cable between ambient pressure sensor and jack twisted / possibly damaged
• Joystick LED (Ambient Pressure Sensor LED) turned ON
• Hub stuck in boot with all four LEDs on

Situation 2

• Wrong Interface cable (i.e., reverse wiring rather than straight wiring)
• Joystick LED (Ambient Pressure Sensor LED) turned OFF
• Hub stuck in boot with all four LEDs on

[jakemcivor]

Preliminary Testing results:

Case	GND	3.3V	SDA	SCL	Notes
Header	GND	3.3V	SDA	SCL	Normal
Reverse	SCL	SDA	3.3V	GND	LED OFF; Nothing on display; HUB LEDs on
SCL NC	GND	3.3V	SDA	NC	LED ON; Hardware error - cable
SDA NC	GND	3.3V	NC	SCL	LED ON; hardware error - cable
3.3V NC	GND	NC	SDA	SCL	LED OFF; Snow on Display; Hub LEDs on
GND NC	NC	3.3V	SDA	SCL	LED OFF; Nothing on display; HUB LEDs on

NC = Not connected. Using a reverse cable or having an intermittent or disconnected ground both produce the Hub LED error case.

[jakemcivor]

Can confirm that at least one more maker had a problem when trying to use a different LipSync interface cable. Need to add a note to the troubleshooting section and component ordering to ensure people order the correct type of RJ11 cable.