NRF24L01 Power, Nano, OLED

Hi guys,

I’m not an expert on anything. I’m an amateur at best, but I’m trying to teach myself a little bit of this and that. I’d really appreciate your guidance on my project, though.

What I have is an NRF24L01 radio module connected to an Arduino Nano (clone) that outputs to an OLED display and is powered by a 3.7v 18650 battery.

The way that I have it connected is the battery charger circuit is connected to the battery, the battery is connected to a step up boost converter set at ~5v. The output of that converter goes through a button switch then one lead to the Nano and another to the RF module. The other side of the button goes to to the Nano 5v and the ground on the RF module goes to the Nano ground.

The OLED VCC and ground are not connected to the Nano.

If I connect my bench supply at five volts to the output side of the regulator, I receive the radio just fine in the serial monitor. If I disconnect the bench and run off the battery, I rarely if at all will receive a transmission. If I connect the USB cable to the Nano with the battery disconnected and the transmitter on the bench supply, I’ll receive the signal. The multimeter reads about 51mA being connected between the regulator and the button while it’s functioning proper.

To my untrained eye, it seems like while on battery power, it isn’t getting enough current. The voltage is set for 5v and I’ve measured 5v throughout the components, but I’m assuming the mA aren’t enough? But I think it should be more than capable? Anyway, can someone help and guide me in a direction that may lead to a resolution? Is it the voltage regulator after all? This one from Amazon is what I have in there.

Hi,

Really confusing and ambiguous description of your circuit. English is a bad language to use for such things. The best language is a schematic, can you please post one. Also links to the specs of the various components used, literally everything including the Nano because there are so many variants of Nano these days.

I suspect the Nano (assuming a classic 5V Nano) was poor choice for a 3.7V Li-ion battery powered circuit. A 3.3V Arduino would be preferable. No boost converter required. The NRF24L01 and oled also run at 3.3V. My guess is that they are being powered from the Nano’s 3V3 pin? It can’t handle the current required.

I don’t have a schematic made at hand, but maybe I can put one together that would give you an idea of what I have going. It is a 3.3v Nano from Elegoo , but you can run them from 5v through the 5v pin. The NRF24L01 with the antenna is notorious (so I’ve read) for not playing nice at 3.3v and it is using the power module board with a 10uf capacitor at 5v. The radio module is being powered with the 5v from the step up regulator. It is from Makerfocus. The OLED is also being powered from the regulator as it is 5v tolerant from Frienda. The step up module is from Frienda. The battery is a generic 3.7v Li-Ion 3400mAh battery.

I’ll see about getting a wiring diagram of sorts together. Again, I am no pro. Please be patient with me.

Probably the biggest problem in using the rf24 radios is insufficient power. The 3.3V regulator on a Nano is too weak. Sometimes a 10uF (or more) cap across the 3.3V supply as close as possible to the radio will help. I use a separate
LM1117 3.3 regulator for my radios. There are adapters available that have the regulators on board. Google “rf24 adapter”.

Thanks, but these are being fed from 5v. The power supply is a 3.7 Li-Ion battery, but that is being boosted by a 5v step up module. The output does show 5v at the RF modules’ breakout board, but I’m thinking there isn’t enough current. There should be, though and that’s the part I’m a little stuck on.

No, I don’t think it is. I’ve never seen a 3.3V Nano V3, and nothing on that page says it is 3.3V. Newer Nano models like the "Nano 33"and similar which are based on 32-bit chips are all 3.3V, but all the “classic” 8-bit Nano, and the “Nano Every” are 5V.

Oh, sorry. You are correct. I misspoke about it being 3.3v. It’s a standard Nano, but it does have the 3.3v output as well as 5v output. In any case, I’m not using the outputs. As I understand, the max output current draw is 50mA. This should be plenty to serve the rf signal. It’s not powering the radio, just supplying the signal. I believe the OLED was less than 20mA, also so the Nano shouldn’t have power issues in that regard.

I believe by talking it through, I can safely say it has to do with the regulator. I should probably replace it with something else.

To maximize battery life, you need to stick to 3.3V components over 5V. Boosting 3.7V up to 5V then regulating it down to 3.3V again is just crazy. It just wastes battery capacity for no benefit. Boost converters are less efficient than buck converters, and linear regulators are even less efficient.

That said, I don’t know why you your less-than-ideal circuit isn’t working at all.

Hi,
Can you please post an image of your project, so we can see your component layout?

Thanks… Tom… :grinning: :+1: :coffee: :australia:

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