The Betaflight VTX Trap: aux_channel Is 0-Based, vtx_power Is 1-Based

Fri, 17 Jul 2026 00:00:00 +0000

Every programmer learns to count from zero. Betaflight agrees: AUX channels are 0-based, so AUX1 is 0 and AUX6 is 5. Type a few CLI lines and your fingers stop thinking about it. Count from zero. It's the rule the whole configurator seems to run on.

Then I lost an evening to a VTX that flatly refused to output 400 mW, and found the one field where Betaflight quietly counts from one instead. Nothing warns you. The failure looked like a dead VTX, not a typo — which is exactly why it ate the whole evening.

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The Betaflight VTX Trap: aux_channel Is 0-Based, vtx_power Is 1-Based