# Connecting ELRS Receiver to Pixhawk 2.4.8 under PX4 Pro - Possible or Not? Need Guidance **URL:** \ **Category:** PX4 Autopilot\ **Created:** [March 10, 2023, 10:13pm UTC](https://discuss.px4.io/t/connecting-elrs-receiver-to-pixhawk-2-4-8-under-px4-pro-possible-or-not-need-guidance/31199 "2023-03-10T22:13:57Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![lstelmah29](https://discuss.px4.io/user_avatar/discuss.px4.io/lstelmah29/32/12648_2.png) [@lstelmah29](https://discuss.px4.io/u/lstelmah29)\ **Post date:** [March 10, 2023, 10:13pm UTC](https://discuss.px4.io/t/connecting-elrs-receiver-to-pixhawk-2-4-8-under-px4-pro-possible-or-not-need-guidance/31199/1 "2023-03-10T22:13:57Z")
Hello, I wanted to ask some questions about the connections to be made with Pixhawk 2.4.8 (sorry, but I’m new). I have Pixhawk 2.4.8 and ELRS receiver. Recently I have successfully paired them following the guide on the ELRS site [Elrs guide](https://www.expresslrs.org/quick-start/ardupilot-setup/), but it works only for ardupilot. So i’m just struggling to find analog of SERIALx\_PROTOCOL = 23 (RCIN) and RSSI\_TYPE = 3 settings in PX4 Thanks! ---
**Author:** ![mdobrea](https://discuss.px4.io/user_avatar/discuss.px4.io/mdobrea/32/7568_2.png) [@mdobrea](https://discuss.px4.io/u/mdobrea)\ **Post date:** [March 11, 2023, 11:02pm UTC](https://discuss.px4.io/t/connecting-elrs-receiver-to-pixhawk-2-4-8-under-px4-pro-possible-or-not-need-guidance/31199/2 "2023-03-11T23:02:48Z")
ELRS receiver communicate with FMU through CRSF protocol. PX4 does not support this protocol. So, in order to do this you need to include a CRSF to SBUS converter. ---
**Author:** ![lstelmah29](https://discuss.px4.io/user_avatar/discuss.px4.io/lstelmah29/32/12648_2.png) [@lstelmah29](https://discuss.px4.io/u/lstelmah29)\ **Post date:** [March 12, 2023, 8:07pm UTC](https://discuss.px4.io/t/connecting-elrs-receiver-to-pixhawk-2-4-8-under-px4-pro-possible-or-not-need-guidance/31199/3 "2023-03-12T20:07:13Z")
Short answer, yes it’s possible. How to do it? You need to set RC\_CRSF\_PRT\_CFG parameter to the serial that you’re using. BUT You can’t use prebuilt PX4 release (or main) firmware for this, as it depends on PX4 modules crsf\_rc. To add RC\_CRSF\_PRT\_CFG to parameter list you need to create your own PX4 build 1. Get PX4 repo and needed items for build (Follow this guide - [Building PX4 Software | PX4 User Guide](https://docs.px4.io/main/en/dev_setup/building_px4.html)), i recommend using ubuntu or WSL ubuntu 2. Build firmware for pixhawk 2.4.8, to do it run “make px4\_fmu-v3\_default” 3. Change config by command “make px4\_fmu-v3\_default boardconfig”. a)In the PX4 board config tool, navigate to the `drivers` submenu, then scroll down to highlight `rc_input`. b) Use the enter key to remove the `*` from `rc_input` checkbox. c) Scroll to highlight the `RC` submenu, then press enter to open it. d) Scroll to highlight `crsf_rc` and press enter to enable it. e) Save and exit the PX4 board config tool. 4. Run build again “make px4\_fmu-v3\_default” 5. Get your build in “\build” folder and install it to your pixhawk 6. Set RC\_CRSF\_PRT\_CFG to serail that you are using, in my case Serial 4/5 port PS: I have connected my receiver to the Serial 4/5 port. Useful links: [Reptile Dragon 2 (RD2) Build | PX4 User Guide](https://docs.px4.io/main/en/frames_plane/reptile_dragon_2.html#firmware-build) ---
**Author:** ![Ludwig\_Ditch](https://discuss.px4.io/user_avatar/discuss.px4.io/ludwig_ditch/32/14762_2.png) [@Ludwig\_Ditch](https://discuss.px4.io/u/Ludwig_Ditch)\ **Post date:** [October 22, 2023, 9:30am UTC](https://discuss.px4.io/t/connecting-elrs-receiver-to-pixhawk-2-4-8-under-px4-pro-possible-or-not-need-guidance/31199/4 "2023-10-22T09:30:34Z")
Hello there , I am having a bit of trouble understanding it , I am totally new to this , I have a Pixhawk 2.4.8 with me and Mission Planner 1.3.80 and firmware Copter V4.4.1 OFFICIAL. I am planning to buy [TX12 Mark II Radio Controller (with ELRS, Mode 2 , FCC region)](https://www.radiomasterrc.com/products/tx12-mark-ii-radio-controller?variant=44128450642151), , I won’t be getting a receiver along with the transmitter . Please suggest me some receiver. and secondly If I have receiver and transmitter is it enough for me to actually be able to control the quadcopter? or do I have to buy any more additional hardware to properly interface all of them together?. (I am not sure if I was clear , for example earlier I had Fsi6 Flysky Fs-I6 2.4G 6Ch Afhds Rc Transmitter Controller with Receiver, all I had to do was bind RC and receiver , connect receiver to Pixhawk 2.4.8 calibrate RC and I was able to fly) Is it the same case with the [TX12 Mark II Radio Controller (with ELRS, Mode 2 , FCC region)](https://www.radiomasterrc.com/products/tx12-mark-ii-radio-controller?variant=44128450642151) too once I buy the receiver ? or do I have to buy any other convertor/ similar hardware for it to work with Pixhawk 2.4.8 and mission planner. apologies for this long post , English isn’t my strongest point. ---
**Author:** ![saints5354](https://discuss.px4.io/letter_avatar_proxy/v4/letter/s/dfb087/32.png) [@saints5354](https://discuss.px4.io/u/saints5354)\ **Post date:** [April 2, 2024, 11:22am UTC](https://discuss.px4.io/t/connecting-elrs-receiver-to-pixhawk-2-4-8-under-px4-pro-possible-or-not-need-guidance/31199/5 "2024-04-02T11:22:09Z")
I still very confuse with all the parameter, is there any easy way? This is what i found using Copilot: Certainly! You can indeed use an **ELRS (ExpressLRS)** receiver with a **Pixhawk 2.4.8** flight controller. Here are some key points to consider: 1. **ELRS Protocol** : - ELRS is an open-source implementation of the closed-source **CRSF protocol** from TBS (Team BlackSheep). - It refers to both the over-the-air protocol and the protocol used between the radio receiver (RX) and the flight controller. - ELRS is compatible with Pixhawk controllers. 1. **Serial Ports on Pixhawk 2.4.8** : - The Pixhawk 2.4.8 has **six serial ports** (UARTs) available for connecting peripherals. - These ports are numbered from 1 to 6. - Any of these UARTs can be used for ELRS communication. 1. **UART Numbering** : - The UART number often doesn’t directly match the serial port number on these ports. - The serial port is what you configure, and the UART number is sometimes used for labeling. - For ELRS, you do not need flow control, so any UART can be used. 1. **Choosing a UART** : - Since ELRS doesn’t require flow control, you can use any UART. - The Pixhawk 2.4.8 has three general-purpose serial ports (Telem1, Telem2, and Telem3). - You can connect your Radiomaster RP1 ELRS receiver to either the **Telem2** or **Telem3** port. - Both are suitable choices, and you can configure them as needed. Remember that ELRS is a great choice for long-range communication, and with the Pixhawk 2.4.8, you have flexibility in selecting the UART for your ELRS receiver. Happy flying! Hope someone can help me out here.