DIN-5

Data

• Board TX to 10Ω resistor
• 10Ω resistor to DIN-5 pin 5 (current sink)

Ground

• Board GND to DIN-5 pin 2 (shield)

Power

• Board 3V to 30Ω resistor
• 30Ω resistor to DIN-5 pin 4 (current source)

TRS-A

Data

• Board TX to 10Ω resistor
• 10Ω resistor to TRS pin 5 (ring)

Ground

• Board GND to TRS pin 1 (sleeve)

Power

• Board 3V to 30Ω resistor
• 30Ω resistor to TRS pin 2 (tip)

TRS-B

Data

• Board TX to 10Ω resistor
• 10Ω resistor to TRS pin 2 (tip)

Ground

• Board GND to TRS pin 1 (sleeve)

Power

• Board 3V to 30Ω resistor
• 30Ω resistor to TRS pin 5 (ring)