From 04ea44ed4bed2f39874acd6ecb0497f7722d0e67 Mon Sep 17 00:00:00 2001 From: pascallanger Date: Mon, 8 Mar 2021 11:19:10 +0100 Subject: [PATCH] Update CPPM_HW_Mod.md --- docs/CPPM_HW_Mod.md | 33 +++++++++++++++++++++++++-------- 1 file changed, 25 insertions(+), 8 deletions(-) diff --git a/docs/CPPM_HW_Mod.md b/docs/CPPM_HW_Mod.md index abf2ad8..d105ff5 100644 --- a/docs/CPPM_HW_Mod.md +++ b/docs/CPPM_HW_Mod.md @@ -1,21 +1,38 @@ # 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. +But this does not work on FrSky radios since the telemetry lines of the internal and external modules are shared. +On a STM32 module and with a simple hardware modification, you can go around this hardware limitation by using CPPM to send the trainer information to the radio. + +There are 2 ways to connect the module CPPM trainer signal available on the STM32 USART1.TX pin (BOOT0 programming TX pin) to the radio: +1. Use the trainer jack input which is supported by all radios. +1. Use the heart beat module bay pin 2, currently supported by erskyTX but not yet by OpenTX. It also seems from reports that not every FrSky radios (X10/X12?) supports this... **After this mod the module should be flashed with the radio off** For the hardware modification you need: 1. 1K resistor -1. wire -1. shrink tube to isolate the resistor -1. soldering iron and solder +1. Wire +1. Shrink tube to isolate the resistor +1. For an external trainer, a 3.5mm mono jack plug +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. +## Trainer jack -## Here is the modification on a Banggood 4-in-1 or an iRangeX IRX4 / IRX4+: +### Here is the modification on a Banggood 4-in-1 or an iRangeX IRX4 / IRX4+: + +![Image](/docs/images/CPPM_BG_IRX4_Jack.jpg) + +### Here is the modification on a Jumper 4-in-1: + +![Image](/docs/images/CPPM_JP4IN1_Jack.jpg) + +## Heart beat within the module bay + +### Here is the modification on a Banggood 4-in-1 or an iRangeX IRX4 / IRX4+: ![Image](/docs/images/CPPM_BG_IRX4_Mark.jpg) +![Image](/docs/images/CPPM_BG_IRX4_Soldered.jpg) -## Here is the modification on a Jumper 4-in-1: +### Here is the modification on a Jumper 4-in-1: ![Image](/docs/images/CPPM_JP4IN1_Mark.jpg) +![Image](/docs/images/CPPM_JP4IN1_Soldered.jpg)