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Posted by brycej | Feb 17, 2019 @ 06:44 PM | 1,808 Views
Hi all,
I'm looking for people with a deviation transmitter and a FC with cc2500 spi (such as crazybeef3/f4 and matek411-one) to beta test a new protocol I've been working on.

This new protocol is roughly 5x lower latency then crossfire and 7-10x lower than taranis with frsky_X.

I've been flying this protocol that I wrote since about Oct. The purpose was to see how low of latency and fast of data rate I could push it. No telemetry for now. It is based roughly on frsky_x (to help with code reuse).

Support is currently with deviationTx transmitters and FC with spi cc2500 chips (Crazybee, Matek411RX, couple others). Looking at a multimodule version as well, but figured I would start here.

Flying really stable at 1.5ms loop time (666Hz). RC looptime and packetsize is adjustable (on deviation menus) for testing for now. Pushed it higher up to 1ms/1kHz rate, but ran into deviation cpu limits (and maybe BF not getting to the spi RX code fast enough always)

Latency results are awesome. 1-5ms from transmitter gimbal to betaflight dshot motor output. Compared to 7-20ms with crossfire on taranis and 18-37ms with frsky_x to X4r on a taranis. Hopping back to my taranis and you can really feel the difference.

4 11-bit channels and 12 1-bit aux channels. Total RC packet squashed down to 12-14 bytes. Although that could be bumped up if needed for anything.

I'll fully write up the protocol when it is pulled in any everything set in stone.

Range is still pretty good even though the...Continue Reading