ExpressLRS is an open source RC link for RC applications, its goals are the low latency and long range. Since it’s open source it’s a lot cheaper than TBS Crossfire, FrSky R9M and similar systems.
Is it better than the more expensive systems?As I’ve seen, yes. ExpressLRS usually performs way better than TBS units, it also depends on the hardware you use. It definitely performs better for the money you’re paying.
The system works for 2.4 Ghz and 900 Mhz frequencies, and the furthest I’ve seen it has been tested was at 40Km using 900Mhz at only 10mW, in my opinion that’s insane, as they show in their Github page a table with the distances they have reached with different settings.
| Max Dist. | Freq | Pkt Rate | TX Power | Failsafe at Max Range? | Pilot Handle | Link to DVR |
|---|---|---|---|---|---|---|
| 40Km | 900M | 50HZ | 10mW | No | Snipes | https://www.youtube.com/watch?v=0QWN9qWoSYY |
| 35Km | 2.4G | 250HZ | 100mW | No | Snipes | https://youtu.be/dBmTRhgVcyY |
| 20Km | 2.4G | 150HZ | 100mW | Yes | Pairan | https://youtu.be/B9-AItJ9WS0 |
| 10Km | 2.4G | 500HZ | 10mW | Yes | mrscythe | https://youtu.be/IpiPEZrCGtg |
| 10Km | 2.4G | 250HZ | 100mW | No | Snipes | https://youtu.be/dJYfWLtXVg8 |
| 6Km | 900M | 100HZ | 50mW | No | Snipes | https://youtu.be/kN89mINbmQc?t=58 |
| 6Km | 2.4G | 500HZ | 250mW | No | Spec | https://www.youtube.com/watch?v=bVJaiqJq8gY |
| 4.7Km | 900M | 200HZ | 250mW | No | DaBit | https://www.youtube.com/watch?v=k0lY0XwB6Ko |
| 3Km | 2.4G (chip antenna RX) | 500HZ | 100mW | No | Spec | https://www.youtube.com/watch?v=kfa6ugX46n8 |
| 2.28Km | 900M | 50HZ | 10mW | No | Mike Malagoli | https://www.youtube.com/watch?v=qi4OygUAZxA |
1. it might not be for you
ELRS is not for everyone, for now it’s not as simple as plug and play most of the times, you need to set up your radio with a lua script, possibly also update the firmware to the latest OpenTX, also update the firmware of both the TX module and Receiver, the DIY solutions require even more work, but it’s totally worth it. In the other hand systems like TBS crossfire are really easy to update and they’re plug and play.
2. do you use flight controllers?
The receivers can only interact with a flight controller using the CRSF protocol, as of 2021 there are no ELRS receivers with standard PWM outputs for servos, BUT… you can use an STM32 blue pill and with the help of this project https://github.com/CapnBry/CRServoF you can create a signal decoder to get up to 8 channels, but again, this is a DIY solution that is temporary, the project is expanding and they might add this in future updates.
Benefits- It’s cheap (open source).
- Compatible with various hardware.
- It’s being developed quickly.
- Micro-size receivers with ceramic antenna (2.4 Ghz).
- Incredible range.
As this project will keep developing with a huge community backing it up the system will get better and better,you can take any openTX capable radio and turn it into a long range setup with the really adorable hardware compatible with ELRS. In my hands I have the BetaFPV module which is more or less simple to flash with the updates, same with the micro receivers.
Sources
ELRS project on GitHub https://github.com/ExpressLRS/ExpressLRS
