Radiomaster, well-known for their radios, has recently released a new series of PWM receivers designed explicitly for fixed-wing use. These ExpressLRS PWM receivers include seven models, namely ER4, ER6, ER8, ER6G, ER8G, ER6GV, and ER8GV. Each one provides unique features designed to cater to different requirements, whether you are a traditional plane, glider, or wing pilot. This review will delve into these receivers’ unique features, specifications, and how they cater to various needs.
Table of Contents
Is ExpressLRS for You?
ExpressLRS has fast become a top contender in the radio link realm of the RC hobby. But the key question is, “Is it right for you?”
ExpressLRS isn’t designed for everyone, it is a bit more complex to use than other existing systems and has a slightly steeper learning curve. However, if performance is your top priority, you’ll appreciate the impressively low latency and long range that ExpressLRS brings to the table. Its open-source nature means continuous improvements are on the horizon as it’s being rapidly developed. Plus, it’s easier on the wallet with a ton of hardware choices. Thanks to its open-source firmware, numerous manufacturers can produce and release their unique receivers and transmitters, giving you more options to choose from at a competitive price.
Note that ELRS V3 can provide up to 16 proportional channels, but the actual number of channels and resolution available depends on the receiver, packet rates and modes configurations. In my experience, this should cater well to most hobbyists’ needs. From a personal standpoint, this open-source journey could prove incredibly rewarding if you’re willing to embrace the learning curve.
To learn more about ExpressLRS, and how to set it up, take a look at my tutorial: A Complete Guide to Flashing and Setting Up ExpressLRS
How does ExpressLRS compares to Crossfire: ExpressLRS vs TBS Crossfire: The Best Radio Control Link for FPV Drones
Where to Buy?
ER4
- AliExpress: https://s.click.aliexpress.com/e/_Dlh8pWl
- Radiomaster: https://oscarliang.com/product-04hv
ER6
- AliExpress: https://s.click.aliexpress.com/e/_DEaKRLR
- Radiomaster: https://oscarliang.com/product-zu9t
ER8
- AliExpress: https://s.click.aliexpress.com/e/_DeInBBP
- Radiomaster: https://oscarliang.com/product-bbdu
ER6G & ER6GV
- Radiomaster: https://s.click.aliexpress.com/e/_DC8Dm37
- AliExpress: https://oscarliang.com/product-i5bn
ER8G & ER8GV
- Radiomaster: https://s.click.aliexpress.com/e/_DCErNWV
- AliExpress: https://oscarliang.com/product-kbqc
A Closer Look at RadioMaster’s ExpressLRS PWM Receivers
The Radiomaster ELRS PWM receiver lineup comprises seven receiver models, each catering to different RC plane specifications and user preferences,
Bear in mind, these PWM receivers aren’t intended for multirotors. Instead, they’re specifically designed for fixed-wing aircraft, as well as other vehicles such as cars or boats that don’t use a flight controller. If you are looking for a receiver suitable for a multirotor, you’d be better off selecting one with a serial protocol output, as I’ve detailed in a separate table.
What sets these new PWM receivers apart are the standout features that were noticeably absent in previous ER5C and ER5A receivers. They now support a DC input ranging from 4.5V to 8.4V, and their telemetry can provide VBAT up to 35V on a single wire. RadioMaster has thoughtfully included extra accessories like wires and heat shrink, simplifying the setup process for users.
You’ll find it straightforward to connect to these receivers using Wi-Fi or any other standard method compatible with an ExpressLRS receiver. They’re also equipped with voltage monitoring for your flight battery, which allows you to keep an eye on the voltage directly from your radio.
One aspect that really caught my eye is the UART port found in the ER6, ER8, ER8G, and ER8GV receivers. This port enables the connection of external sensors, paving the way for for potential additional sensor capabilities from RadioMaster in the future.
They support EU LBT, which can be chosen in the build option when flashing receiver firmware. Looking to the future, the upcoming ExpressLRS 3.3.0 firmware release is set to introduce SBUS as a serial port output option for PWM receivers. I’m hopeful that these PWM receivers will support this feature and can be configured for SBUS Out. In fact, I believe that most, if not all, PWM receivers should be capable of this.
General Purpose: ER4, ER6, and ER8
The ER4, ER6, and ER8 receivers are the all-rounders of this new series. As traditional receivers, they’re all PWM-based, with the ER4 providing 4 PWM outputs, the ER6 offering 6, and the ER8 delivering 8. Each model comes with a boot button and a dedicated solder pad on the back (EXT-V), allowing you to connect your battery voltage for convenient telemetry readouts.
ER4
The ER4 stands out for its lightweight and minimalist design featuring a single antenna. It embodies simplicity and efficiency at its finest. I’ve personally put this receiver to the test in my own wing, which requires only 3 channels, and so far, it’s performed flawlessly.
The ER4 is a perfect match for smaller devices, such as cars, boats, or fixed-wing aircraft. Its operating range between 4.5V to 8.4V allows it to be powered directly by 5V or a 2S pack. It offers a relatively smaller telemetry power of 10mW, which is adequate for ground applications where telemetry power isn’t as crucial.
ER6 and ER8
The ER6 and ER8 models feature a more traditional box-style design, enclosed in a plastic cover with two antennas on it. While they don’t offer full receiver diversity, they do provide antenna diversity, which is still beneficial for improving overall performance. The ER6 closely mirrors the ER8, only with 2 fewer PWM outputs. The 8-channel ER8 receiver is an ideal fit for more complex RC planes, particularly jets that come with additional features such as landing gears and flaps.
The ER6 and ER8 serve as robust, general-purpose receivers, featuring a dual antenna design and a maximum telemetry power of 100mW. They both feature an UART port for external sensors. Weighing in at 14.2g and 16.3g respectively, they’re as durable as they are efficient.
I must say, the presentation and build quality of these receivers is top-notch. I particularly appreciate the attention to detail, like the rubber strain relief for the antennas on the ER6 and ER8. It’s these small touches that truly elevate these devices.
For Gliders: ER6G, ER8G, ER6GV, and ER8GV
Radiomaster’s G-Series brings to the table four specially designed, compact receivers meant for gliders: the ER6G, ER6GV, ER8G, and ER8GV.
This series offers both 6-channel and 8-channel receivers, with vario options (GV models) and without (G models). For those unfamiliar, a vario is a device that indicates an aircraft’s rate of climb and descent—a critical tool for glider pilots.
ER6G and ER8G
The ER6G and ER8G feature a compact layout of pin headers, ensuring a smooth fit into your aircraft. Both models come with dual antennas and an external voltage pad for battery input. However, the ER6G does not have a UART port, which the ER8G offers for connecting additional sensors. If you’re considering future sensor expansion, the ER8G would be your model of choice.
Built for gliders, both the ER6G and ER8G can operate on a 1S and 2S pack (input voltage 3.5V to 8.4V). While the ER6G tips the scales at just 4.7g, the ER8G offers two extra channels with a negligible weight increase, coming in at 4.8g.
ER6GV and ER8GV
The ER6GV and ER8GV models are virtually identical to the ER6G and ER8G but boast an integrated vario sensor. Same as the ER8G, the ER8GV also offers a UART port for external sensors, a feature that the ER6GV lacks. Again, if you’re considering the flexibility to add more sensors, the ER8GV would be your receiver of choice.
As for their weights, the ER6GV weighs 11.9g, and the ER8GV comes in slightly heavier at 12.1g. Overall, whether you prefer a simple setup or are a fan of additional features, the G-series has a receiver for every glider pilot’s needs.
How to Use
The ELRS receivers arrive ready-to-use, straight out of the box. They come pre-installed with the ExpressLRS v3.2.1 firmware. Hence, there’s no need to update anything unless you desire to do so. Simply bind them with your radio, and you’re all set to go.
Configuring the Receivers
These receivers can be set up via Wi-Fi. For your initial setup, wait for 60 seconds for the receiver to enter Wi-Fi mode, indicated by a rapid flashing LED. Then, join the ExpressLRS_RX Wi-Fi network on your laptop and configure the RX using the webpage with the address: 10.0.0.1.
On this page, you can enter your bind phrase, along with other settings like failsafe channel fall-back, and so on.
Binding and Telemetry
You can bind the receiver without needing to enter a bind phrase. Upon powering the receiver for the first time, it should automatically enter bind mode, indicated by a double flash. If not, you can manually reset the receiver by holding the boot button for 10 seconds.
Once bound, the receiver should start picking up all available telemetry sensors. You’ll find 1RSS (signal strength), RQLY (Link Quality), and RXBT, which represents the battery voltage connected to the EXT-V pad. If EXT-V pad is not connected, it will display the receiver voltage at the pin. If you’re using the ER6GV and ER8GV, you will also see altitude data from the built-in vario sensor. Moving the receiver up and down should reflect changes in altitude measurement, indicating that it’s functioning correctly.
Calibrating Voltage
While my telemetry reading was accurate out of the box, you might want to verify yours. You can compare the telemetry reading with a multimeter. If required, there’s an option to manually calibrate the telemetry voltage sensor, and rest assured, it’s a straightforward process.
Final Thoughts
RadioMaster’s newest ExpressLRS PWM receivers bring to the table a wide range of options, introducing a new level of compatibility and functionality that I believe will greatly benefit users.
The receivers, particularly those equipped with the UART port, have the potential to revolutionize telemetry options. I look forward to future expansions, such as the addition of GPS modules and current sensors, to these receivers. These enhancements will undoubtedly elevate the user experience even further.
Get your receiver from here:
ER4
- AliExpress: https://s.click.aliexpress.com/e/_Dlh8pWl
- Radiomaster: https://oscarliang.com/product-04hv
ER6
- AliExpress: https://s.click.aliexpress.com/e/_DEaKRLR
- Radiomaster: https://oscarliang.com/product-zu9t
ER8
- AliExpress: https://s.click.aliexpress.com/e/_DeInBBP
- Radiomaster: https://oscarliang.com/product-bbdu
ER6G & ER6GV
- Radiomaster: https://s.click.aliexpress.com/e/_DC8Dm37
- AliExpress: https://oscarliang.com/product-i5bn
ER8G & ER8GV
- Radiomaster: https://s.click.aliexpress.com/e/_DCErNWV
- AliExpress: https://oscarliang.com/product-kbqc
10 comments
Can i connect an er6 receiver to a flight controler?
Yes. PWM receivers can also output any supported serial protocol, such as CRSF or SBUS. Select the desired output protocol using the ExpressLRS lua script, or on the Model tab in the receiver’s WebUI. The default pins used for serial output vary by receiver.
Buenas tardes
Recientemente he adquirido un rx Radiomaster ER8GV y no se como configurar la telemetría adecuada
La telemetría que me da es la siguiente:
1 1 RSS = -11 dB variable (no se lo que es)
2 2 RSS = -8 dB variable (no se lo que es)
3 RQlY = 100 % variable (no se lo que es)
4 RSNR = – 9 dB variable (no se lo que es)
5 ANT = 1 variable (no se lo que es)
6 RFMD = 7 fijo (no se lo que es)
7 TPWR = 50 mW fijo (no se lo que es)
8 TRSS = -8 dB variable (no se lo que es)
9 TQlY = 100 % variable (no se lo que es)
10 TSNR = 12 dB variable (no se lo que es)
11 RxBt = 5.4 V fijo por ser el voltaje que le llega al receptor
12 Curr = 5.4 A fijo (no se a que amperaje se refiere)
13 Capa = 5 mAh fijo (no se a que mAh se refiere)
14 Bat% = 5% fijo (no se a que tanto por ciento se refiere)
15 Alt = -0.2m me imagino que es la altitud
16 VSpd = 0.0 m/s (no se lo que es)
El problema es que no se cual el RSSI como en los demás receptores
Tampoco se como configurar el voltaje de la batería al ser posible por celdas
si tuvieras la amabilidad de echarme una manita te lo agradeceria mucho pues me gustaria configurarlo lo mejor posible para poder volar con la máxima seguridad
gracias anticipadas por todo y perdona por el royo
Saludos Jose
Hello Oscar and thank you for your articles which help me a lot. I use a radiomaster zorro and radiomaster receivers in my gliders. I can’t display the altitude on the Zorro screen with the er6GV receiver. The receiver is correctly paired with the correct version of elrs. Is there a special procedure? What should be the source of a vario? Thank you. Guillaume
Thank you so much for this! One question is, can I connect a satellite receiver to any of these? I’d like to have receiver redundancy. Is that possible?
I was hoping to connect my ER series receivers(ER4, and ER6) to an FC (Aura 8) via SBUS. I am having trouble finding information about doing this. If it is possible and what steps or configuration options would need to be set. I can see in the wifi configurator that SBus and CRSF are options but can not find and data on how to implement them.
I’m trying to find how to connect an ER8 to a FC Sbus as well, and can’t find any info either. If I figure out how I will try to reply.
Another great article – thanks.
But on the RM site, it says the 6-channel versions only output 50mw for telemetry – do you have different information?
Thanks!
The ER6 has 100mW while the ER6G and ER6GV are 50mW.
with matek CRSF to pwm converter we can map the channel 5 pwm output with either elrs channel 11 or 12 instead of channel 5, thus having a real pwm output and not a on/off one.
Is it possible to do the same on these and if yes how ?? is it what you call channel fallback ?