EzUHF SBus Low Latency Beta firmware

By January 13, 2016Uncategorized
What it’s all about
When flying fast and agile mini-quads, the time to transmit control information from remote to flight controller plays an important role. Latency in the transmission forces you to anticipate every move and has an impact on the precision on the race track.

How it works

The firmware diminishes latency by:

  • synchronizing the whole transmission path from the remote to the receiver,
  • augment transmission rate
  • send less channels for shorter packet transmission
  • use digital input to the JR module and digital output from the receiver to the flight controller instead of PPM

What’s different

  • lower transmission latency
  • Only SBUS on output 1. Other outputs are not used
  • No Failsafe: Output is synchronised to packet reception, so no reception, no output. Use the flight controller’s failsafe
  • 6 channels

Why a beta?

To get SBUS working with the standard EzUHF hardware and lower the latency, we made a lot of changes that impact speed of transmission, timing and synchronisation. So it’s important to do extensive tests to see the impact it has on range and reliability of the transmission and how it recovers from lost connections and interferences.

This firmware is mainly for mini-quads, that don’t fly as far out as big planes.
  • Don’t take risks and don’t put it on your big expensive model
  • Check and set the failsafe in your flight controller
  • Fly carefully and please report on if you notice any range issues and glitches or control loss

Please give us feedback in the FaceBook EzUHF Owner Group

Beta Firmware Test setup procedure

Short version

  1. download the files
  2. upgrade the firmwares with the ImmersionRCTools in the downloaded file
  3. set the remote External RF output to DSM2/DSMX
  4. connect to your Vortex
  5. bind
  6. run the wizard to assign the channels correctly
  7. set the subtrims in the remote to have the center at 1500

Physical Setup
Connect the EzUHF from output 1 to the SBus input of your Vortex, like you would do with any SBus receiver.

ImmersionRCTools Beta Usage
unzip the downloaded file somewhere. It contains two files: EzUHFFirmware_race_sbus.zip and immersionRCTools.zip  The first contains the firmware files and the second contains ImmersionRCTools that recognises the SBus firmware version. Unzip both.

The Beta ImmersionRCTools is in a folder instead of distributing an installer, as you should already have the official version and drivers installed. This way, the beta won’t mess up your official installation. Just double-click on ImmersionRCTools.exe to run the application.

Upgrading the firmwares of the EzUHF works the same as usual. Binding works the same too. See summary below if you forgot.

Settings

In ImmersionRCTools, there is not a lot to setup, it works as the usual EzUHF Tx Setup. On the RX, you can’t set the servos outputs, as it only uses output 1. You can set up another channel mapping with the PPM slots and output RSSI, Link Quality or UPSTAT (but this isn’t currently supported by the OSD).

In the remote, you need to set the output:

Model Setup -> External RF -> Mode: DSM2 DSMX.

Then, rerun the wizard in your Vortex to set the channel mappings. It should recognise the SBus firmware with recent firmwares. Use the Wizard or Cleanflight Configurator to configure the subtrims to 1500 (SBus defaults to 1525).

In the quadcopter flight controller, check and configure the failsafe. Current versions of Vortexes should be set up to just cut the throttle after a short time of not receiving data.

 

 

 

Upgrade and binding procedures summary

TX firmware upgrade Procedure

  • start ImmersionRCTools on the computer
  • remote off
  • power switch on “Hi”
  • plug in USB connector while holding the bind button pressed
  • LED should blink
  • In IRCTools, in the EzUHF TX Program tab, the “Update Firmware” button should turn from grey to white if it’s detected by the computer.
  • Press “Update Firmware”, select the “EzUHFFirmware_TxJRModule_race.fw” file
  • Done!

TX firmware upgrade Procedure

  • start ImmersionRCTools on the computer
  • remote off
  • plug in USB connector while holding the bind button pressed
  • LED should blink
  • In IRCTools, in the EzUHF RX Program tab, the “Update Firmware” button should turn from grey to white if it’s detected by the computer.
  • Press “Update Firmware”, select the “EzUHFFirmware_Rx4ch_race_sbus.fw” file
  • Done!

Binding Procedure

Same as usual, other than the LED blinking that now reports more issues:

  • power switch on “Lo”
  • start the remote while powering up the remote. JR Module should beep regularly in bind mode
  • give power to the receiver, if it’s not bound, it should flicker fast.
  • press the bind button until the LED turns off.
  • wait until it blinks again: 3 blinks: success, 6 blinks, failure.
  • Done, restart!

Now, when it’s receiving packets, the LED should be solid, if it doesn’t, it flickers. You see on startup the little time it flickers when it synchronises to the signal.