hx_espnow_rc

Goals:

hx_espnow_rc

Remote control library based on ESP-NOW protocol (PlatformIO, ESP32 and ESP8266)

Transmits 16 channels at 50 Hz, bidirectional telemetry(transparent stream) and RSSI, A1, A2.

Can be used as cheap RC for LOS flights or up to 1km flights. Main goal is to use it in the DIY ESP8266/ESP32 based projects.

Used in external RC Controler JR Bay module: https://github.com/RomanLut/hx_espnow_rc/blob/main/doc/tx_external_module.md

Used in DIY RC Controller: https://github.com/RomanLut/hx_espnow_rc/blob/main/doc/tx_diy_controller.md

Used in DIY ESP32 based quadcopter: https://github.com/RomanLut/Multiwii-ESP32-port

Used in DIY ESP8266 plane: https://www.youtube.com/watch?v=c9dDOX0IzME

Used in INAV 1.7.3 plane: https://www.youtube.com/watch?v=UptvxsFHDFA

Used in INAV 3.0.2 plane: https://youtu.be/GYB-UckucRA

You can build transmitter module for RC Controller with External module bay, DIY RC controller, and SBUS/PWM receiver using guides below.

See building guides:

transmitter module for Jumpter T-Lite (JR Bay): https://github.com/RomanLut/hx_espnow_rc/blob/main/doc/tx_external_module.md
DIY RC Controller: https://github.com/RomanLut/hx_espnow_rc/blob/main/doc/tx_diy_controller.md
module for Radiomaster TX16s JR bay [todo]
Servo/PWM/Discrete output receiver based on Wemos D1 mini board: https://github.com/RomanLut/hx_espnow_rc/blob/main/doc/rx_d1_mini_pwm.md
ESP-01 based SBUS receiver: https://github.com/RomanLut/hx_espnow_rc/blob/main/doc/rx_esp01_sbus.md
Wemos D1 Mini based SBUS receiver: https://github.com/RomanLut/hx_espnow_rc/blob/main/doc/rx_d1_mini_sbus.md
ESP32 based SBUS receiver: https://github.com/RomanLut/hx_espnow_rc/blob/main/doc/rx_esp32_sbus.md
Wemos D1 Mini based Mavlink RC receiver: https://github.com/RomanLut/hx_espnow_rc/blob/main/doc/rx_d1_mini_mavlink_rc.md
ESP32 based Mavlink RC receiver: https://github.com/RomanLut/hx_espnow_rc/blob/main/doc/rx_esp32_mavlink_rc.md
Wemos D1 Mini based PPM receiver: https://github.com/RomanLut/hx_espnow_rc/blob/main/doc/rx_d1_mini_ppm.md
ESP32 based PPM receiver: https://github.com/RomanLut/hx_espnow_rc/blob/main/doc/rx_esp32_pmm.md
development guide: https://github.com/RomanLut/hx_espnow_rc/blob/main/doc/development.md
recommended antenna: DIY Moxon antenna https://www.thingiverse.com/thing:5148464

Range

2 dbi dipole antenna on transmitter with:

PCB antenna provide range less then 150m.
whip antenna with stripping wire provide range ~250m
2dbi dipole antenna provide range ~1Km (!)

5 dbi dipole antenna on transmitter with:

2dbi dipole antenna provide range ~1.3Km (!)
2dbi dipole antenna and ESP32 LR receiver provide range ~1.8Km (!)

Moxon antenna with:

2dbi dipole antenna and ESP32 LR receiver provide range ~1.7Km (!)

Failsave period is set to 1 second (so there should be at least 1 successfull packet delivery in 1 second). Note that range of actual communication is larger, but is not usefull for RC.

2dbi dipole antenna on transmitter <-> 2dbi dipole on receiver provide range up to 1Km:

Tested with INAV 1.7.3 Naze32 1s flying wing based on Eachine E58 brushed motors, with HX_ESPNOW_RC SBUS Esp-01s based receiver https://www.youtube.com/watch?v=UptvxsFHDFA.

I have got first failsave event at 950m and still could control plane at 1100m:

5dbi TP-Link antenna with RP-SMA-SMA adapter on transmitter <-> 2dbi dipole on receiver provide range up to 1.3Km:

5dbi TP-Link antenna with RP-SMA-SMA adapter on transmitter <-> 2dbi dipole on receiver, ESP32 LR mode provide range up to 1.8Km(!):

Tested with INAV 3.0.2 DF mini Spirit 1s flying wing, ESP32-based SBUS receiver, LR mode https://youtu.be/GYB-UckucRA

DIY Moxon antenna on transmitter https://www.thingiverse.com/thing:5148464 <-> 2dbi dipole or receiver provide range up to 1.8Km:

Tested with INAV 3.0.2 DF mini Spirit 1s flying wing, ESP32-based SBUS receiver, LR mode.

DYI moxon antenna perform similar to 5dbi antenna, while having compact size.

Moxon antenna is recommended antenna for hx_espnow_rc project.

I also tested with Frsky directional patch 7dbi antenna clone, and I was not able to get any good result with it. I got a lot of failsafe events at 700m already.

I am not sure if this is caused by poor clone quality, my ability to point in the right direction, or poor antena SWR. (I know I have to open the clone and rotate inner part in the right direction).

Telemetry

Telemetry stream is transparent and CRC protected. Data is ensured to be delivered without distortion, unless failsave or overflow condition araise. Stream can be used to transfer Mavlink, MCP, Sport, LTM etc. telemetry. Data rate is ~57kBit/sec. Additionally library transmits A1 and A2 (32-bit) values for simple telemetry.

See packets timing: https://github.com/RomanLut/hx_espnow_rc/blob/main/doc/rfpower/rfpower.md

Building and Flashing

Currently pre-build firmware is not provided. You have to build firmware yourself and flash ESP32/ESP8266 modules using PlatformIO https://platformio.org/

If you do not know what PlatformIO is, than this project is not for you at the current stage. Later I may try to provide pre-build binaries and detailed instructions for flashing and configuring transmitter and receivers.

See development guide: https://github.com/RomanLut/hx_espnow_rc/blob/main/doc/development.md