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Topic: Shutter control with NRF24L01 - overheating problem (Read 719 times) previous topic - next topic

Prieme401

Hi all,

I recently made a setup to control my shutters through my mobile phone.
Therefore, I used an arduino mega with ethernet shield on my router. On this Arduino Mega, I connected a wireless transmitter NRF24L01 with voltage regelator in between my Mega and the transmitter.

At my shutter, a used an Arduino Uno with the same setup. Additional, on this, I attached a self designed circuit to control a solid state relay (SSR) for switching power and a mechanical relay for switching between left and right winding of the motor.

With the blynk app, I manipulate values which I send through the wireless transmitter to my Arduino Uno at the shutter. This all works fine, but my wireless transmitter (receiver) on the shutter side (on the Arduino Uno) seems to get very hot. The one on my Mega (sender) doesn't. That's the weird thing, I can't figure out why the one on my Uno is heating. Is it the circuit that I built that is interfering with the circuit on the wireless transmitter?

I attached my schematic here. Extra info:
- For the wireless transmitter and the voltage regulator designed for this transmitter, I only represented the power suply, the other connections are data transmission and connected to different pins on my Arduino Uno (just like on the Mega)
- Transmitter: NRF24L01 + PA + LNA (see image attached)
- Voltage regulator: with AMS1117 step down converter (see image attached)

Does anyone know what is wrong with my setup?

pylon

The relay should have a flyback diode.

I cannot find a reason for the NRF module to get hot. Have you tried to exchange the two modules? If you do that does still only the one at the UNO board get hot?

silly_cone

have you taken a voltage reading to make sure you really are only sending 3.3V to the NRF?  If the regulator is damaged from reverse polarity, for example, it can fry an NRF.  The only time I've ever had NRF's get hot on me is when they've been damaged in this manner from mistakenly connecting the power supply backwards (now I try to incorporate reverse-polarity protection using a mosfet).

Prieme401

Normally, the addapter on which the NRF module is plugged in is a voltage regulator which from my understanding provides 3.3 V to the NRF module and is powered with 5V from the Arduino. Polarity is correct, but it might have been switched once in the past, that I'm not sure. I'll try to swap the NRF module with a new one (I have spares to use on my other shutters). I'll come back to this if it isn't solved.

have you taken a voltage reading to make sure you really are only sending 3.3V to the NRF?  If the regulator is damaged from reverse polarity, for example, it can fry an NRF.  The only time I've ever had NRF's get hot on me is when they've been damaged in this manner from mistakenly connecting the power supply backwards (now I try to incorporate reverse-polarity protection using a mosfet).

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