RClatency Tester

This code is designed to run on an ESP8266 board and measures the end-to-end latency of various RC protocols. You will need an ESP8266 nodemcu or similar.

General

Supported Hardware

Select the correct Hardware in your IDE

• nodemcu V1
• nodemcu V2/ V3

Supported Protocols

• CRSF V2
• GHST
• SBUS
• IBUS
• Spektrum SLRX2

Setup and Test

Wiring

nodemcu Pin	Target	Wire Color	Note
D0	Remote Throttle Stick	orange	disconnect the Throttle stick from the PCB
GND	Remote Ground	gray	any ground connection in your remote
D7	Receiver TX pad	turquoise	RC output pad of your Receiver
GND	Receiver ground	black	./.
VU or 3V3	Receiver voltage supply	red	select the pad with the suitable voltage level for your receiver

Setup

You can adjust the Receiver protocol as well as the number of test runs in main.cpp

• #define NumOfTests 500 change this line to adjust the number of tests
• Adjust the Receiver protocol by uncommenting it and out-commenting the other protocols before uploading the code:

  //#define USE_GHST
  #define USE_CRSF
  //#define USE_SBUS
  //#define USE_IBUS
  //#define USE_SRXL2

Run a Test

• Connect the nodemcu to the remote, receiver and your PC by USB
• Open your IDE with PlatformIO and select monitor
• When the connection is running, the terminal output will show:

  Softserial Mon Started
  Press Button to Begin Test
  CRSF UART Connected

• Press the Flash button on the nodemcu to start the test
• The terminal will output the results after each test

Output

• Test Number: Actual test number
• Delay: Time between trigger set on the remote and received change on the receiver
• Consistency: Time between the RC messages

Test number	Delay	Consistency
1	4385	4025
2	7896	3998
...	...	...
500	3976	4185