Wireless remote control

I am trying to build a wireless remote control to control 9 relays in an outside the house camera unit.

I have tried 3 versions of the nRF24Lo1 but both lose control pulses through house walls to the outside world. Wireless models are marked 2Gig and 2.4Gig.

I had previously given up with 433Mhz units, and thought 2Gig units would be better. I don’t want to give in to using wire unless all avenues are exhausted.

Control outputs are for Pan left/Pan right/ Tilt up/ Tilt Down/ and 5 OSD settings to camera. All simple momentary signals.

Any ideas how I can get better wireless output. Thanks

Current code (only shown with 3 switches)


#include <printf.h>
#include <RF24.h>
#include <RF24_config.h>
#include <nRF24L01.h>
int msg[1];

RF24 radio(7, 8);
const uint64_t pipe = 0xE8E8F0F0E1LL;

int SW1 = A0;         // asign button pin A0
int SW2 = A1;         // asign button pin A1
int SW3 = A2;         // asign button pin A2
void setup(void) {

void loop(void) {
  if (digitalRead(SW1) == LOW) {     //  button SW1 pressed
    msg[0] = 10;
    radio.write(msg, 2);
  if (digitalRead(SW2) == LOW) {    //  button SW2 pressed
    msg[0] = 15;
    radio.write(msg, 2);
  if (digitalRead(SW3) == LOW) {    //  button SW2 pressed
    msg[0] = 20;
    radio.write(msg, 2);


Have you tried using the high powered nRF24 with the external antenna for one of the pair of devices?

Or maybe an option would be to use a 3rd nRF24 (and Arduino) as a relay between the walk-about device and the external device.

...R Simple nRF24L01+ Tutorial

Thanks Robin,

Yes I have tried all units I think, with and without antennas.

One is marked power output 100mW with antenna on, marked E01-ML01DP5.

There was another RF24-Master library I came accross where it had a wireless power output setting, but I passed over it, due to the fact of spending time getting the library I am using now.

Someone mentioned HC-12 module to me but have not looked yet, maybe another 433mHz unit?

ZOR2: One is marked power output 100mW with antenna on, marked E01-ML01DP5.

You need to post a link to a datasheet for that sort of info to be meaningful.

You did not comment on the idea of using a 3rd device as a relay.


All three units came from Ebay. I tried finding datasheets in the beginning but gave up as in Chinese or different ver varients.

2.4G 22dBm 100mW nRF24L01P+PA+LNA Wireless (gave best results, fitted antenna)

2.4G nRF24L01+ Wireless Transceiver Module + SMA, Antenna

nRF24L01 2.4GHz Antenna (pcb track antenna)

The idea of a repeater in the middle is a good idea, one I will look at seriuosly if I cannot get 2 units of some sort.

I looked quickly at the HC-12, and is 433mHz, but has a 1km range. I think it might be illegal at that power.

Will look into it, I saw there was an Arduino HC-12 library, maybe power output reduction.

ZOR2: one I will look at seriuosly if I cannot get 2 units of some sort.

Time vs money.

But it seems you already have 3 nRF24s so why not do a test?


Thanks again, I will get a third Arduino so I can try some sort of repeater going.


I'm using HC-12s and they seem to be solid. In US at that band and power there are no legal issues I know of. I do some RF for Television for a living and would hope I'd know but may be wrong.

Many thanks altoaudio, good to have confirmation. I know 433mHz is ok in uk, not so sure about legal side of their power output. I thought 315mHz was allowed in USA.

It would be good to have just two devices in the system, reducing the hardware of the third. But I will give both ideas some time. The units will spend most of the time static, as only for odd times the camera needs moving or OSD settings changed.

Thanks again

It would be interesting to hear how you get on if you try the HC 12 modules.


Will do Robin, ordered from China. Only thing that worries me is the output is 100mW, the same power as one of the nRF24LO1 devices I have. I read that in the UK, we are only allowed a quarter of the power 25mW, so could be dodgy. I will look at only turning the wireless on in transmit when I want to tweak the camera, so it won't be on all the time. Don't want to see a white van outside. Regards

I'd go back to using 433MHz. Lower freq gets through barriers. I was able to control a wireless device in my backyard when I put the transmitter in my basement.

INTP: I'd go back to using 433MHz.

That's what the HC-12 is.


Try using a High Gain antenna on the reciever. They tend to be much longer. Also make sure it is well away from metal objects, and that your Earth on the module, and antenna is to a fairly large area of metal like a box. Antennas should be parallel to each other. This should improve reception. Likewise you could do the same with the transmitter.

If that fails, then try moving the controller away from the camera by a wire that may end up being closer or through less material without being a full wired system.

Are you using a protocol that repeats the sequence to account for lost data? Try to experiment to see if it is a distance thing or an interference thing.

Thanks Richie_asgl.

My tests were done by continually sending a message from the transmitter (in Void Loop), and illuminating an LED in the receiver.

When both units were i close proximity, the LED was stable, but as I moved away it started flickering until it finally went out.
I did think of wiring part way up to the unit to break the distance but that was not so practicle.

Will wait for the HC-12 to arrive and see how they perform.

Thanks again

Just to say my HC-12 devices arrived. They are excellent, there is no problems going through walls compared to Nrf24Lo1, which were prone to breakup. Even with the versions with on board amplifiers.

I have to check the power output settings of the HC-12 to check they are not unlocking nearby cars (laugh). The units can be configured with AT commands but have not got that far yet. My remote will not be used all the time so I should be okay.

All other 433mhz boards (Ebay) in the past were poor, so I was surprised on the performance with the 433mhz HC-12.

Thanks for the update.


Hi Robin, your welcome, I promised to get back. Regards