EzUHF radio control system

The ImmersionRC EzUHF is a 433MHz switchable 200mW or 600mW output one-way wireless control system. Suitable for long range (10km+) and critical situations where a good remote control link is required.

• ImmersionRC EzUHF product page

EzUHF transmitter

• Model: EzUHF 200/600mW Transmitter silver
  
• Purchase date: 2012-08-22
• Transmitter ID: 985
• Stock firmware version: 1.25a (6)
• Upgraded firmware version: 1.25b (6)
• Frequency band selected: 436-438MHz

Print a label with the unique transmitter ID and put it on the transmitter. Makes it easier to check if any neighboring EzUHF flyers use the same ID.

EzUHF receiver

• Model: EzUHF Receiver
• Purchase date: 2012-08-22
• Channels: 8
• Diversity: two dipole antennas
• Stock firmware version: 1.24 (6)
• Upgraded firmware version: 1.25b (6)
• Frequency band selected: 436-438MHz

Spectrum Norway

The spectrum space in Norway follows most of the European line of distribution. The entire 430-438MHz band is dedicated for amateur use.

• Frequency allocations Norway - pdf

Drivers

The driver install is not straight forward, at least not on Windows XP. The USB driver failed to install and a manual driver update had to be done, poin the path to c:\Program Files\ImmersionRC\ImmersionRCTools.

Software

The ImmersionRC software is quite good and fairly straightforward. The receiver tab include a simplified spectrum analyzer, very useful to determine the condition of the RF environment. Here I picked the 436-438MHz range to get a considerably cleaner band.

Bind

To configure the receiver to listen for the transmitter, perform the following binding procedure:

1. Toggle the transmitter power switch to Low
2. Hold the bind pushbutton while turning on the transmitter
3. Turn on the receiver and hold the bind pushbutton on the receiver for 5 seconds
4. Move the sticks and check the control output on the receiver

Failsafe

The UHF receiver will wait 1 second before jumping into failsafe mode if the transmitte signal is lost. To set the failsafe paramters do the following:

1. Position the sticks in the desired failsafe configuration, e.g. throttle low, slight down elevator and slight aileron turn - on multirotor make sure to adjust the travel range for the flight mode switch to land inside the "Failsafe" zone so that the flight controller knows that it has lost signal
2. Hold the EzUHF transmitter bind button until a series of single beeps are heard, release button - this can be done on the ground or in the air - the failsafe values are saved by the receiver

Important: when using a multirotor and NAZA, this has to be done on the ground when the flight mode channel is trimmed to trigger one of the NAZA failsafe zones - use the NAZA Assistant to view these zones

Firmware upgrade

The firmware upgrade process is simple and recommended to keep the units up-to-date. Make sure to test the units properly after upgrading the firmware to find any new quirks.

Transmitter:

1. Start by disconnecting the radio power to the transmitter, USB will provide the power during flashing
2. Remove the antenna, switch the power switch to High and hold the pushbutton
3. Plug in the USB cable and install the new Immersion RC Custom USB Device driver
4. The red LED should start blinking
5. In the IRC tool, the Update Firmware button should now be activated, uncheck Preserve Configuration for a full restore
6. Pick the correct .fw-receiver firmware (Tx500) and upload the code, should take about 10-20 seconds, a sequence of beeps indicates it's done
7. Mount the antenna and re-plug the USB cable to load the new firmware, configure it using the IRC tool
8. Lastly, enter firmware mode again and hit Fix Fuses to make sure everything is set up

Receiver:

1. Disconnect any power from the R/C model, power is supplied by the USB connection
2. Hold the pushbutton next to the servo-headers using a plastic tool
3. Plug in the USB cable and install the new Immersion RC Custom USB Device driver
4. The red LED should start blinking
5. In the IRC tool, the Update Firmware button should now be activated, uncheck Preserve Configuration for a full restore
6. Pick the correct .fw-receiver firmware (Rx8ch) and upload the code, should take about 10-20 seconds
7. Unplug the USB cable and re-insert it to load the new firmware, configure it using the IRC tool
8. Re-bind the receiver with the transmitter and more importantly configure the failsafe
9. Lastly, enter firmware mode again and hit Fix Fuses to make sure everything is set up

References

• ImmersionRC EzUHF product page
• Long Range System review