Nano+RF24L01+ TMRh20 Libs + Starter code = no workie.

Hey folks,

Hardware: Robotdyn Nano knockoff with a Robotdyn RF24 knockoff. I went with a Nano because I wanted small and I went with Robotdyn because they boasted high current on the 3.3VDC line of their Nano. This would ostensibly solve all the trouble I'd read about with the sensitivity of the 3.3Vdc on these RF24+ modules. But for good measure I soldered on a 10uF cap between 3.3V and ground anyway. The Nano and RF24 module are hardwired (soldered) together and the only deviation from the recommendation is the CSn (SSn) is on pin 10, not 8. This is because according to the Nano pin-out pin 10 a dedicated CSn pin.

Software: Downloaded the TMRh20 library and put it where it belonged. For a sketch I used the starter code from YourDuino. It looks like so many other RF24 starter, or "Getting started" programs - oops, sketches, and it compiled.

Since I am more interested in RF testing I decided to forego the second, "receive" module and set only one module to dutifully transmit at a 500ms clip. Along with my 2.4GHz spectrum analyzer I'd have all I need for my initial 2.4GHz band RF experimentation. Or so I thought.

So far, I see nothing on the waterfall of my spectrum analyzer. With the two antennas practically touching I see not even a glitch. Either this RF24 module has the most poorly tuned antenna ever, or my set-up simply isn't transmitting. Based on what I've seen when these things actually work, I'm betting on the latter.

So, finally a question, when using the TMRh20 libraries, do these RF24 modules need to be paired to transmit? When I look at the serial monitor for the transmitter it prints and increments just like the sketch tells it to, but I don't see a corresponding 500ms blip on my spectrum analyzer.



Have a look at this Simple nRF24L01+ Tutorial.

The examples are as simple as I could make them and they have worked for other Forum members. If you get stuck it will be easier to help with code that I am familiar with.

And if you need more help please post a link to the datasheet for your Robotdyn device


Thanks, Robin. I remember reading your tutorial when I was initially surfing around about these little modules. I probably should have stayed right there. Better late than never, eh? Anyway, your code compiled and loaded onto my Nano. All I changed was the CE pin, which I have wired to pin 7. Assuming that everything under the hood is working, I'll start looking for dependable blips on my spec-an and then report back.

Oh, how do I change channels? I've gotta add a line in the "Set up" section, correct?


Oh, how do I change channels? I've gotta add a line in the "Set up" section, correct?

If you just want to use a different channel for everything then select it in setup().

It is entirely possible to change channels on the fly but there is great scope for a horrible mess if the Tx and the Rx are not both on the same channel.

Wireless problems can be very difficult to debug so get the wireless part working on its own without any changes to my code before you start adding any other features.


I inserted the necessary line of code for channel adjustment. It compiles and loads, so all good there. Still nothing significant shows on my 2.4GHz spectrum analyzer. The next step is to guaranty basic transmission with a receiver, as you suggest. That'll need to wait until new hardware comes in.

Cheers till then.