Performance considerations vs drehmflight

[jonbjornn]

Started this originally as an issues but then noticed there were active discussions!

Love the fact that this supports a wider range of hardware, but wondered what compromises had to be made to support such drastically different mcu clock speeds?

What do you give up in comparison to drehmflight in order to gain the broader hw compatibility?

[qqqlab]

Actually not many compromises where made, I think the performance between drehmflight and madflight will be similar. The different hardware platforms in madflight are implemented with #defines, and don't affect runtime.

The drehmfight target teensy 4.0 runs at 600MHz, whereas most madflight targets run at less than half that clock speed.

Drehmflight uses software oneshot125 to drive the ESCs, which introduces a wait of up to 125us in each 500us loop, i.e. up to 25% of computing power is wasted. madflight uses hardware pwm to drive the ESCs.

Neither drehmflight nor madflight use DMA, which would probably be the first thing to implement if somebody is really concerned about performance.