What is FETtec OneWire?

„OneWire“ is a half duplex serial protocol with a 2M Baudrate created by Felix Niessen (former Flyduino KISS developer) from FETtec. For example, you can connect a 4in1 ESC with only 1 Signal wire and 1 GND wire to your FC. By the way, OneWire is limited to 24 ESCs (You hardly ever have to use more than 8 for a drone).

Check out my interview with Felix.

What was DShot again?

Check out my article about Dshot!
And for the real nerds: Sinwave / BackEMF Hybrid-Commutation

What is a Serial Connection?

Serial interfaces send/receive their data in binary pulses.

More Info here: Serial Communication

Simplex

The Simplex method is a one-way communication technique. If a sender (TX) transmits, the receiver (RX) can only accept the transmission.

Half Duplex

Half Duplex can send/receive in both directions, but just one direction at a time.

Full Duplex

Full Duplex can send and receive simultaneously in both directions.

Settings and CRC

OneWire scans for new ESCs automatically. Besides that, you can change way more settings of the ESC over OneWire than over DShot. It also has a better cyclic redundancy check (CRC) than Dshot offers. CRC checks if there are any signal errors that occur in the communication between FC and ESC

Telemetry

After every sent throttle-signal, a telemetry response from the ESC will be returned. You might know the RPM-Filter in Betaflight. This filter needs the RPM value from each ESC in order to work correctly.
With OneWire however, in addition to the RPM values of each ESC, there are also various other telemetry data (e.g voltage, amp draw, …) which is also sent back to the FC. Furthermore, the FC can decide which ESC Telemetry value should be sent back. This open up room for new filters and features to be developed and integrated in the future.

How fast is FETtec OneWire?

When using 4 ESCs at the same time, you will have a 8kHz looptime which equals Dshot600.

How to wire FETtec OneWire up?

You only need two cables. OneWire (Telemetry) and GND.
In my connectionplan for the FETtec FC, you can see in the lower right hand corner how to hook up OneWire.