Nigel
Moderator
Background
If you've ever used FrSky (as most people who've visited this forum have) you will likely know the saga of firmware versions and updating. Without going into detail, it's an utter mess. Most of us likely only know the mess of 2.4 firmwares, the same headaches and issues also plague FrSky's 900Mghz system, the R9M line of hardware.
Thankfully, there is a solution: ExpressLRS. ExpressLRS is an open source firmware written for use specifically on OTX radios and various 900Mghz and 2.4Ghz hardware ecosystems, most notably including not only the R9M 2019 OTA, but also the older pre-2019 ACCST R9M modules and receivers.
Why switch?
There are many reasons. Not only does it incorporate new technology into your link like LoRa, it is also entirely free and un-restraining - you can always flash back to factory firmware if you choose, unlike other protocols, ImmersionRC Ghost being a prime example. It will provide a more friendly user experience through its use of a configurator (similar to OpenTX) and in-radio script configuration, as well as better performance. It boasts improved range, latency, and overall performance, putting it light-years ahead of FrSky's stock R9M firmware. Most notably it has extremely high refresh rates - 200Hz, pipping Crossfire's 150Hz, as well as outperforming Crossfire for high refresh rate range (these modules will swap to lower refresh rates when the link starts to deteriorate, leading to a noticeable negative change in response).
FrSky has always made good hardware, and this firmware will hopefully allow people to use it to its full potential with ease. It will also function on a range of other systems.
So, are there any downsides?
There are a few. Most notably, you will need to flash a unique OTX version to your radio - all functionality and such remains the same, it simply adds another step and complexity. If you are already running a unique OTX version for ImmersionRC Ghost or Crossfire Shot support, it is already built-in to the ExpressLRS version - meaning you are still fully compatible.
If you wish to use the Pre-2019 ACCST R9M module, you will need to remove a single resistor - this is fairly easy to do, and is documented in this video here.
To see a full video detailing the process of updating R9M hardware, go to this video here.
GitHub Link: ExpressLRS
Here's a snapshot of the range found with third-party testing: (Credit: Oscar Liang)
If you've ever used FrSky (as most people who've visited this forum have) you will likely know the saga of firmware versions and updating. Without going into detail, it's an utter mess. Most of us likely only know the mess of 2.4 firmwares, the same headaches and issues also plague FrSky's 900Mghz system, the R9M line of hardware.
Thankfully, there is a solution: ExpressLRS. ExpressLRS is an open source firmware written for use specifically on OTX radios and various 900Mghz and 2.4Ghz hardware ecosystems, most notably including not only the R9M 2019 OTA, but also the older pre-2019 ACCST R9M modules and receivers.
Why switch?
There are many reasons. Not only does it incorporate new technology into your link like LoRa, it is also entirely free and un-restraining - you can always flash back to factory firmware if you choose, unlike other protocols, ImmersionRC Ghost being a prime example. It will provide a more friendly user experience through its use of a configurator (similar to OpenTX) and in-radio script configuration, as well as better performance. It boasts improved range, latency, and overall performance, putting it light-years ahead of FrSky's stock R9M firmware. Most notably it has extremely high refresh rates - 200Hz, pipping Crossfire's 150Hz, as well as outperforming Crossfire for high refresh rate range (these modules will swap to lower refresh rates when the link starts to deteriorate, leading to a noticeable negative change in response).
FrSky has always made good hardware, and this firmware will hopefully allow people to use it to its full potential with ease. It will also function on a range of other systems.
So, are there any downsides?
There are a few. Most notably, you will need to flash a unique OTX version to your radio - all functionality and such remains the same, it simply adds another step and complexity. If you are already running a unique OTX version for ImmersionRC Ghost or Crossfire Shot support, it is already built-in to the ExpressLRS version - meaning you are still fully compatible.
If you wish to use the Pre-2019 ACCST R9M module, you will need to remove a single resistor - this is fairly easy to do, and is documented in this video here.
To see a full video detailing the process of updating R9M hardware, go to this video here.
GitHub Link: ExpressLRS
Here's a snapshot of the range found with third-party testing: (Credit: Oscar Liang)
