An I2C bus was flooded with interrupts
What ArduPilot says:
- Internal errors 0x80000 (i2c_isr)
External compasses, airspeed sensors, some rangefinders and LEDs are on I2C, a two-wire bus shared by all of them. During one exchange the processor counted more interrupts from the bus than can happen when it works, gave the exchange up and recorded i2c_isr. The device on that bus missed at least one reading; the flood itself takes processor time from everything else.
What to do, most likely first
A cable or connector on the I2C bus is loose, too long or runs along power wires.
CheckWiggle the GPS/compass cable with the board powered, props off, and watch for compass or airspeed errors at the same moment.
FixUse a short cable with its wires twisted, away from the battery and ESC wires, and seat the connectors firmly.
One device on the bus is faulty and holds the lines.
CheckUnplug the I2C devices one at a time; the error stops with the bad one removed.
FixReplace that device.
Where to do it:Board & Wiring Planner