The parachute is enabled, but nothing is set up to release it

What ArduPilot says:

• Chute has no relay
• AP_Relay not available
• Chute has no channel

CHUTE_ENABLED is 1, so ArduPilot checks that it could really release the parachute. With CHUTE_TYPE 10 (servo) one output must have SERVOn_FUNCTION 27 (Parachute): if none has, “Chute has no channel”. With CHUTE_TYPE 0 (relay) one relay must have RELAYn_FUNCTION 3 (Parachute) and a pin: if none has, “Chute has no relay”. “AP_Relay not available” means the firmware was built without relays.

What to do, most likely first

1. The release is a servo, and CHUTE_TYPE is still 0 (relay), its default.

   FixSet CHUTE_TYPE to 10, and SERVOn_FUNCTION to 27 on the output the release servo is wired to.

2. No output has been given the parachute function.

   CheckLook through the SERVOn_FUNCTION values for a 27.

   FixSet SERVOn_FUNCTION to 27 on the release servo's output, then check CHUTE_SERVO_ON and CHUTE_SERVO_OFF (the released and the closed position, in µs) with the parachute unpacked.

3. The release is a relay, and no relay has the parachute function and a pin.

   CheckSince ArduPilot 4.5 the relay is chosen by RELAYn_FUNCTION 3, not by CHUTE_TYPE 0 to 3 as older guides say.

   FixSet RELAYn_FUNCTION to 3 and RELAYn_PIN to the pin the release circuit is on.

4. No parachute is fitted.

   FixSet CHUTE_ENABLED to 0.

Test the release on the bench with the props off and the parachute unpacked or its charge disconnected. In 4.6 and milardu “AP_Relay not available” is never shown, because the code forgets to fail the check (AP_Parachute.cpp line 234); 4.7 fixes that.

Parameters to look at

Where to do it:Board & Wiring Planner