CRSF Link tester and packet monitor

A testing tool for Crossfire and ExpressLRS receivers based on ESP32 microcontroller and 320x240 SPI display

Features

Realtime visualization of

• RSSI, LQ, Link Rate and TX power
• Up to 10 RC channels
• Scrolling colored indicator of received, bad and missed packets

Limitations

• Only 320x240 ILI9341 SPI displays are supported
• ELRS full resolution switch modes not supported

User interface

M5Core2	ESP32 2432-S028 HMI Module

• RSSI bar, minimum range is based on RX sensitivity for given packet rate (ELRS)
• LQ: Link quality bar
• PW: Current power of the transmitter
• PR: Current packet rate in Hz
• Numeric values and graphical bars for 10 RC channels
• Text and scrolling packet indicator: each vertical line reppresents a received (or not) RC packet:

Good RC packet received

RC packet timeout

Bad serial RX frame or CRC error

Update rate and packet timeout are based on link rate, packet timeout = (1 / PacketRateHz * 1.5) seconds **

It's OK to see red missed packets at regular intervals with telemetry turned on, because these time slots are used by receiver to transmit back the telemetry packet.

Programming and flashing

Basically the process is the same as for ExpressLRS and VSCode, just modify the platformio.ini file and select the correct serial port for flashing How to compile with VSCode for ESP32

Wiring diagram for M5 Core2