This is the second part of BetaFPVs ELRS lineup. As mentioned in my previous post, BetaFPV released two additional AIO flight controllers with ELRS receivers on board. Those boards are obviously a great fit for the BetaFPV ELRS Lite Radio. But can be used with any 2.4GHz ELRS transmitter.
The two flight controllers have a very similar feature set, but slightly different implementation and form factor. I will first look at the differences and why you might chose one over the other and then look into similarities of those flight controllers.
A big “Thank you” to BetaFPV at this point who sent me those flight controllers for review.
1S Whoop ELRS AIO
The BetaFPV F4 1S ELRS AIO is specifically designed for 1S whoop and will fit all common 65, 75 and 85mm frames with the 29mm mounting pattern. It is cross shaped for minimum possible weight - it weighs in at just 3.13g including the ELRS receiver and antenna.
The ESCs are capable of pushing 5A continuous and 6A burst. The ESCs are BLHeli_S compatible and have a O-H-5 - basically BetaFPVs staple layout that they use on all of their 1S AIOs. Since the ESCs are BLHeli_S compatible and also *come with BLHeli_S flashed, you can also run Bluejay on them if you want to go with RPM filtering. BetaFPV even mentions that they are compatible - it’s really a pity that they do not come pre-flashed with Bluejay.
Depending on your exact setup you might even be able to gain some additional flight time with Bluejay over BLHeli_S.
The integrated ELRS antenna is a chip antenna, so the board will fit nicely in most already available canopies without modifications. You will not have full range with this chip antenna, but it will be a way better than what you are used to from the FrSky compatible SPI receivers. It’s so good, that it’s actually not even comparable - you will definitely out fly your video signal.
The motor plugs came pre-soldered on mine. The pads for camera, SmartAudio and VTX are all on the edge of the PCB and should be easy enough to solder to. Unfortunately there is only one GND and 5V pad available so if you don’t use a VTX from which the camera can be powered too, it will be a bit fidgety to wire everything up.
One UART is broken out and a SBUS pad is available - should you want to run a different receiver for whatever reason. Buzzer pads are also available.
It comes in at a price of $39.99, which is pretty fair for what you get - at least in my opinion.
1-2S ELRS Toothpick AIO
The second AIO flight controller boasts higher rated ESCs, capable of pushing 12A continuous. The form factor still has the 29mm mounting pattern, but the USB port is on the side, rather than on the bottom, so this one is a better fit for all your toothpick needs. It weighs in at 3.9g without battery wire and ELRS antenna and 5.8g with BT2.0 connector and ELRS antenna.
To be more specific: The USB port is actually plugged in via a connector, so it will fit easily into whoop styled frames too, without the USB connector being in the way. This is an interesting design choice, although a bit fidgety to need an extra connector to get everything set up.
Caution: This flight-controller is available in two versions - you want the V2, the V1 is not capable of actually running off of a 2S battery. In the BetaFPV shop you should only get the V2 anyway, just keep that in mind when buying from a different vendor.
The ESCs have the new Z-H-30 layout and are fully supported by Bluejay, but only come flashed with BLHeli_S although the product description mentions Bluejay. The dead-time is not as low as I would like, but still on the lower side - so nothing to complain about really.
This board is super versatile and you can easily run a 3”, 2S toothpick from this board. The motor plugs (BetaFPV gives you straight and angled connectors) are included but not pre-soldered on this one. The solder pads are on the edge of the board and are thus easy to solder on to.
Two spare UARTs and SBUS pad, should you - for whatever reason - want to run a different receiver are available. This time they also give you an additional 5V and GND pad. Buzzer pads are also available.
This one features a full sized ELRS antenna for maximum range.
With a price tag of $44.99 it is only a bit more expensive than the dedicated whoop board, and an excellent price for what you get.
Having looked at what sets them apart, let us now have a look at what they have in common:
Both come with BetaFPVs in house BT2.0 connector. I do not use this but instead use a solid pin PH2.0 connector, but this is easy enough to swap out.
Since those boards are running Betaflight 4.3 you will need an up to date version of Betaflight Configurator - I am using the nightly build of version 10.8.
At the time of writing both are only available as nightly/development builds, but Betaflight 4.3 is already pretty mature in my opinion.
Right now, the biggest downside is, that you have to use the Betaflight hex file that is provided by BetaFPV, otherwise you will not be able to use the SPI ELRS receiver. This is a bit of a bummer, especially since I had massive problems with flyaways with their default CLI settings on the 2S board. I had to manually reset some values to default via CLI since it would not properly work from the configurator.
SPI ELRS Receiver
Both boards come with ELRS receivers that are connected via SPI, so flashing the firmware can not be done via WiFi as you might be used to from the “full sized” ELRS receivers but will rather be flashed when flashing BetaFlight. This will hoefully be fully integrated once Betaflight 4.3 is released - both boards come flashed with a pre-release version of Betaflight 4.3. I say “hopefully” because the ELRS SPI PR does not yet have a 4.3.0 label, so there is no guarantee that it will actually be integrated in 4.3.0.
The SPI receivers integrated on those boards only come in 2.4GHz, so nothing in the 900MHz spectrum, but this was pretty much expected - does not make sense to put 900MHz antennas on a whoop.
The big downside of SPI receivers is, that they will only work with Betaflight - at least for now - so no Emu or Quicksilvler.
To bind with the on board SPI receiver open Betaflight configurator and on the Receiver tab click the “Bind Receiver” button on the bottom right (alternatively you can bind via Betaflgiht CLI). On your radio, put your ELRS module into binding mode. Order is important here: First the receiver, then the transmitter.
Once bound, the blinking green light on the FC will go solid.
I tried to bind both flight controllers with the dedicated ELRS Lite Radio, the BetaFPV ELRS module (v1.0.1) and the Happymodel ELRS (v1.0.1) module and all three of them worked without any issues.
Binding via passphrase is also an option - please see the ELRS wiki to learn more about this.
According to the ELRS Wiki SPI receivers do not need to be updated. and will work with any version of ELRS on the transmitter.
Update is only possible via Betaflight and the firmware for the SPI receiver is basically “baked” into the Betaflight firmware - starting with Betaflight 4.3.0 (hopefully).
At first I was a bit disappointed that the ELRS receiver is not hooked up via UART but SPI instead - but looking at it closer and seeing that updating the firmware is still possible (albeit not really necessary) gives me a peace of mind.
I especially like the 1S whoop board and it will probably be my goto flight-controller for all my 1S builds moving forward. No more shitty FrSky compatible SPI receivers - I am really happy about that.
In my tests both flight controllers have been working very reliably for the past couple of weeks, so I can recommend both of them without hesitation.
The only down side for me is, that it has to run Betaflight 4.3.x which is not stable at the time of writing. So right now, I would only recommend you get this flight controller if you are willing to invest some time in setup and know your way around Betaflight well enough to troubleshoot some problems along the way.