How to solve nodemcu will bring interference to the circuit

5V(USB-2A) directly connected to the nodemcu VCC and GND above, there is a 443m wireless transceiver module is also connected to the above, but nodemcu will interfere with 433m wireless transceiver

This interference makes 433m unable to work stably. The remote control always sends a signal, but the received signal is intermittent

Wiring diagram


Physical wiring diagram

My experiment is similar to this experiment, but he does not seem to find the interference.

This interference makes 433m unable to work stably. The remote control always sends a signal, but the received signal is intermittent

I have used RC filter or use 1000uF capacitor parallel to the power supply, there are some effects, but still not very good. What should I do?
Currently I have 1000uF 470uF 220uF capacitors and resistors of different sizes, several triodes. I do not have an inductor, how can i make nodemcu and 433m work properly?

Your rats nest of wiring looks much more complex than your diagram!

The NodeMCU uses 3.3v logic, so unless you’re using a logic level converter, you shouldn’t be powering the 433Mhz receiver with 5v, otherwise you’ll fry your MCU. Most of these 433Mhz devices can operate on 3.3v.

Can you simplify the wiring for testing purposes - just the NodeMCU and the the 433Mhz transmitter, and Post a diagram of EXACTLY how you’re connecting and powering the two devices?


Thank you very much for your answer, then I just checked it, nodemcu should be able to connect to the 5V. I do not understand why you think nodemcu can not connect to 5V power supply.

5V power connection in Vin and GND, I also connected to the 433m module 3.3V and GND above, the effect is even worse.

The NodeMCU used 3.3v logic levels.
It can be powered by 5v, either through the USB port or the 5v Vin pin. This voltage is then reduced to 3.3v by the onboard voltage regulator.
If you supply 5v to another device in your circuit then connect a digital output from that device to one of the GPIO pins on your NodeMCU then you’ll be overloading the NodeMCU and will kill it at some point - probably sooner rather than later.


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In actual fact the NodeMCU will probably be fine. We have been using 5V with the WeMos D1 Mini to drive our RF transmitters for years without any ill effect. We have a resistor to limit current but that’s all. It’s because of the voltage drop through the transmitter and it’s the same with a lot of components.

You just need to put a meter on the data pin of the component before you connect it to the MCU.

What should I do?

I’d suggest powering the transmitter with 3.3v to begin with, and see what the interference is like then.
Your latest photo shows a resistor and an LED connected to the transmitter board, but I can’t see any data connection to the NodeMCU.
Can you show us exactly how you’re connecting-up the NodeMCU and the transmitter?


5V power connection in Vin and GND, I also connected to the 433m module 3.3V and GND above, the effect is even worse.

Okay, I’m a bit confused about what you’re trying to achieve here.
I assumed that the NodeMCU was either receiving or transmitting data using the 433Mhz transceiver module, but as you have no data connection between the transceiver and the NodeMCU, maybe I’ve got the wrong end of the stick.

What is the role of the NodeMCU in this circuit?

I thought you were doing something like this:


@mtrucc I am still trying to determine the reason this is posted on a Blynk forum… I don’t see Blynk being used here, nor any Blynk related questions :wink:

Regardless… ESP’s are known to cause some small RF interference (you see a lot of this with IR sensors), so try moving your 433mhz transceiver further away.

@PeteKnight Yes, my situation is similar to this experiment.
But my 433m wireless transceiver module will be Nodemcu interference.
When I use the 433m module separately, I can receive signals from 3 meters.
But I will 433m module with Nodemcu a piece of time, 433m can not work, can only receive 0-30 cm signal.

@Gunner Thank you very much for your reply, probably because my English is not good enough and the expression is not very clear.
I would like to note that Nodemcu with 433m module share a power supply (without filtering, etc.) may be due to Nodemcu frequency is too high and interfere with the 433m module

I think you need to buy cheaper RF modules as the $1, maybe less now, transmitter / receiver pairs can get 10 meters with a 5V feed. In fairness we have a box of receivers that we have never used as we just use the transmitters and the suppliers will not split the pairs even for bulk orders.

Other than regular electronic interference the ESP’s don’t mess with the RF stuff as it’s quite a different frequency. As pointed out by @PeteKnight you don’t appear to be connecting the data lines so it will not work even over a distance of a few mm.

Please provide a proper diagram of the connections.

@Costas I let Nodemcu and RF 433m share a power supply. I used a Led to discover that Nodemcu interferes with the RF 433m module and did not use the RF 433m module to transmit signals to Nodemcu. I now expect to solve this problem.

But GND a Vcc is not enough for the RF receiver to interface with the MCU. What about the data?

@Costas I do not need to transfer data to Nodemcu, I just want to solve the interference problem, this is just part of my circuit, and then I will show you the key part. I found this part of the interference, so I need to solve this problem.

How do you know you have interference if you are not connecting the data lines?

@Costas I use the remote control to transmit the signal to the 433m receiving module,
When the Nodemcu and 433m receiver module shared power, the remote control from the 433m module 0-10cm to receive the signal, and is intermittent, very unstable.
When only 433m receiving module power supply, Nodemcu no power, 433m can be received within 2m remote control signal, and very stable.

You are not making any sense but I will advise accordingly.

As pointed out by others, locate the RF receiver as far away from the MCU as possible. You should be able to locate it several meters from the MCU and still have enough power in the circuit.

You can try powering the receiver from it’s own power supply and up to the maximum voltage. Our transmitters accept 12V, never used the receivers but your maximum might be different. Just provide a common ground to the MCU.

Hope this helps in some way.