Using the AutoPi With an External Power Supply

This guide is applicable to the following device / devices:

TMU CM4

CAN-FD Pro

CAN-FD Pro +IP67 casing

---

Your AutoPi is preconfigured for in-vehicle use. In a lab or bench setup, you can power it from an external power supply through the OBD connector.

Recommended for testing and troubleshooting

Using an external power supply is an excellent option when validating configurations, reproducing issues, and troubleshooting behavior outside a vehicle.

Before You Connect

1. Always power the AutoPi through the OBD connector. Do not use the Raspberry Pi power inputs. Doing so can cause AutoPi features to behave incorrectly and may damage the device.

2. Use a stable power source. AutoPi may power down automatically when voltage drops below 12.2 V to protect the vehicle battery. For lab use, supply at least 12.5 V and use a power supply capable of at least 2.5 A.

3. Be aware of sleep timer behavior. If no communication is detected on the vehicle CAN bus, a sleep timer can be triggered.

Useful Commands

You can run AutoPi Core commands locally or over SSH.

• Local terminal format: power.status
• SSH format: autopi power.status

The autopi prefix works for all AutoPi Core commands. See commands documentation for a full reference.

To inspect sleep timers, run power.sleep_timer. To clear timers, run power.sleep_timer clear=*.

Recommended Cable

For easier connection to an external power supply, we recommend the OBD power cable available in our shop: OBD-II Power Cable.