Fixing nRF24L01+ Modules Without Going (Too) Insane

Fixing nRF24L01+ Modules Without Going (Too) Insane

nRF24L01+ module fixed about as well as it can be, by adding an appropriate capacitor on the PCB antenna, and a 1.0 uF capacitor across the power pins for good measure.

Good old nRF24L01+ wireless modules are inexpensive and effective. Well, they are as long as they work correctly, anyway. The devices themselves are mature and well-understood, but that doesn’t mean bad batches from suppliers can’t cause hair-pulling problems straight from the factory.


[nekromant] recently got a whole batch of units that simply refused to perform as they should, but not because they were counterfeits. The problem was that the antenna and PCB design had been “optimized” by the supplier to the point where the devices simply couldn’t work properly. Fortunately, [nekromant] leveraged an understanding of the problem into a way to fix them without going insane in the process. The test setup is shown in the image above, and the process is explained below.


This issue wasn’t new to [nekromant], as previous batches had suffered from a “magic finger problem”, where bad performance is magically solved by placing one’s finger on the antenna. This had been fixed in the past by soldering in a missing 1.0 pF capacitor, but the newest batch of nRF24L01+ units was so bad that something more needed to be done. Simply adding a 1.0 pF capacitor was no longer enough, and it’s unclear exactly why.


For reasons likely related to the PCB antenna, each radio required adding a capacitor in a value usually somewhere between 1.0 pF and 2 ..

Support the originator by clicking the read the rest link below.