UART

There is a TX and RX pin on all Head Tracker boards that can be used for SBUS or CRSF. There is currently three options supported.

SBUS in + out

• Some radios support SBUS as a Trainer option, this is a digital system, fast and accurate. If you have it available it's preferred over PPM.

• It will allow you to transmit 16 channels on the TX pin

• You can also receive 16 channels on the RX pin

  • Receive can be used if you need to connect more than one Head Tracker to your radio. It can support a much faster update rate.

• Invert - These will invert the SBUS signal either RX or TX.

  • On the Nano33BLE series of boards there is a limitation on the NRF52840 processor SBUS input requires you to solder D5 and D6 together for invert to work. If your unsure if you need not-inverted just solder them together when assembling, it won't hurt anything.

  • The DTQSYS board has this done internally, please ignore the message. It will be corrected in the next GUI.

CRSF Input

• Allows you to receive channels using the CRSF protocol. There are no options to configure here. CRSF should be attached to the TX and RX pins. Not sure of a use for this yet but it's here is someone wants it 🎉
• Could be used to hook two Head Trackers together wirelessly using a ELRS TX & RX, but since you can't transmit and receive at the same time would need to have a wired connection to the radio.

CRSF Output

• Update Rate

  • This is the rate the channels are updated at. Leave this at the maximum unless you have a custom application.

• Use channel 5 as AUX1/ARM

  • This option will force channel 5 to be always on at 2000us. This is needed for an ELRS transmitter. ELRS uses this channel for reasons listed ->Here. If your using Crossfire or Tracer leave this un-checked.
• CRSF Output Level

  • This will invert the TX pin signal, if your using a JR Bay type transmitter (Crossfire, Tracer or ELRS) this needs to be checked. You should hook the TX pin on the Head Tracker to S.PORT pin on the JR module. RX on the HT is not connected. You will also connect GND(HT) -> GND (Module). You will also need a way to power it on the VMAIN pin, that one is up to you 😄

  

  • If connecting to a ELRS receiver that has been flashed to be a transmitter, leave this box un-checked. For instance the Happy Model EP2 ELRS Setup which can be used as a trainer link.