From 3a5d3415142baa35f8fb86a801f850d57e4ae218 Mon Sep 17 00:00:00 2001 From: pascallanger Date: Sun, 7 Mar 2021 17:31:45 +0100 Subject: [PATCH] CPPM hardware mod initial page --- docs/CPPM_HW_Mod.md | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) create mode 100644 docs/CPPM_HW_Mod.md diff --git a/docs/CPPM_HW_Mod.md b/docs/CPPM_HW_Mod.md new file mode 100644 index 0000000..692e643 --- /dev/null +++ b/docs/CPPM_HW_Mod.md @@ -0,0 +1,20 @@ +# CCPM Multi module hardware modification + +By default Multi uses the telemetry line to send the received channels using a RX protocol (FrSky, DSM, AFHDS2A, Bayang) to the radio. +But this does not work on FrSky radios since the telemetry lines of the internal and external modules are shared (hardware limitation). +On a STM32 module and with a simple hardware modification, you can go around this limitation using CPPM to send the trainer information to the radio. + +For the hardware modification you need: +1. 1K resistor +1. wire +1. shrink tube to isolate the resistor +1. soldering iron and solder + +The goal is to add the 1K resistor between the STM32 USART1.TX pin (Boot0 programming TX pin) and the radio bay pin 2. + +Here is the modification on a Banggood 4-in-1 or an iRangeX IRX4 / IRX4+: + + ![Image](/docs/images/CPPM_BG_IRX4_Mark.jpg) + +Here is the modification on a Jumper 4-in-1: + ![Image](/docs/images/CPPM_JP4IN1_Mark.jpg)