Buy FOCBOX Unity

Simple 3D-printed NRF remote - Arduino controlled



Thx money is on the way


Just be aware that a cap wired this way may cause issues for your Arduino when using the IDE (for debugging or updates). You may need to remove it to get it to work.

When I had some trouble getting my transmitter working, I tried a bunch of things including wiring a cap in this way.

Turns out my issue was actually that my battery voltage wire was connected on the wrong side of the switch so my transmitter wasn’t properly rebooting when it was switched on. I left all the other stuff wired up (cap between reset and ground, resistor between RX and TX), because I figured it wasn’t doing any harm.

When it came time to debug my transmitter I found it wasn’t playing nice with the Arduino IDE - something to do with not being in sync or something. Once I removed all the extra stuff it returned to working flawlessly.

The reason I think it’s the cap is because the error messages I was getting were apparently to do with the Arduino reset not being in sync with the IDE… the IDE expects the board to reset at certain times during the writing process. I suspect the cap was interfering with this and causing the board and IDE to be out of sync.


@SeeTheBridges Are you taking any orders for complete builds ?


Not at this time. I can take limited parts only orders, but I’m not home enough to assemble completes


Its a good idea to put hot glue on all the solder joints where wires come out. its so easy to get a loose wire while using this thing hard. This is why i prefer a PCB… looks much safer.


Ok Guys. I have built the remote and receiver with the Development codes for both. I am using FOCBOX running version 2.18. I am getting no movement in the BLDC ppm monitor. How do I check if the TX and RX are really talking. Do I need to update the focbox firmware to something else? Any Advice appreciated


Done the debug and me moving the wheel changes the value but not in Ack maniac esc tool (updated my Focbox to latest FW). tried both ppm and ppm and uart.

Oh BTW this debug was done with the receiver unplugged from the vesc


is the code for feather chip, same as for arduino?


Solved Issue was a unfiltered 5v that was stuffing it up added some filtering and problem was fixed.


Only if you use the 328P feathers and do some custom re-mapping of the pins and such…


Why doesn’t work?


Nrf24 chip doesn’t like the voltage changes at all. It is not a problem but rather a drawback in feather boards. In order to maintain 3.3v on the system they use a linear voltage regulator and it can’t keep it up when battery drops to around 3.5v depending on the diode they use to switch between usb and battery power. So having a big battery helps to keep the voltage higher for longer so the voltage regulator can do it’s job properly. Battery in the original firefly Bom is good enough but only if you charge it after every ride.
Probably using 5v switching regulator is the best to use the battery to its fullest potential and drop the voltage only for the nrf. That is actually how original design works.
Another option is to use 2s battery to keep the voltage input high enough but that just complicates the charging system.


Yea, it gave me issues when I tried to go on there for a reference last night. It’s back up now. If it happens again, you can at least go to a cache page to see the information you need.


anyone knows how to increase the power of the NRF? I have set PA_MAX and when the hand covers the remote control, NRF lost connection :confused:


Which NRF module and how did you position it?

I find the module (and antenna if you have one) are extremely fussy when it comes to placement within the remote itself.



I have this nrf:


Yeah this one is not the best module to get… I am using these now…

[E01-ML01S SPI nRF24L01P 2.4Ghz 1mW PCB Antenna IoT uhf Wireless Transceiver nRF24L01 PA LNA Transmitter Receiver rf Module](E01-ML01S SPI nRF24L01P 2.4Ghz 1mW PCB Antenna IoT uhf Wireless Transceiver nRF24L01 PA LNA Transmitter Receiver rf Module


thank you!
what do you think about this:
I ordered a week ago


I use this too… but you’ll need an external antenna.

The antenna position within the remote is very sensitive, having it in the wrong place means zero signal for some weird reason.


does this have a 3.3v regulator??