esp32 c3 rc522 df player mini there is a voltage drop in the circuit

Thread Starter

memedin

Joined Dec 24, 2022
30
I want to play music from dfplayer mini with an rfid card reader. When I set up the circuit on the plate, I get a voltage drop, I don't know why, very meaningless ı use 5vto3v3 ams1117, entry 10uf exit 10uf and normally I was going to feed it with tp4056, I would switch my circuit with a switched potentiometer as seen in the top left, but I get a voltage drop esp32c3.png
 

MisterBill2

Joined Jan 23, 2018
19,351
The collection of isolated details in post #2 requires a lot more effort to visualize the circuit described.
As for the problem, it seems to be a voltage drop of some amount between two unspecified points.

So clearly either one device does not have an adequate operation supply voltage because it requires a greater difference, or there is an excessive resistance in a connection, which might even be in the common side of the circuit. Which was not ever mentioned at all.
So while a PCB Auto-router can work very well with a net-list and drawings of blocks, I find using it for diagnostics and functional evaluation much less convenient.
So the very first question is between which points is the voltage drop, and the second question is how much voltage drop between the various connected points. Knowing that information will make finding the cause a simple task. Without that information, the answer is already provided in the third sentence.
 

Thread Starter

memedin

Joined Dec 24, 2022
30
The collection of isolated details in post #2 requires a lot more effort to visualize the circuit described.
As for the problem, it seems to be a voltage drop of some amount between two unspecified points.

So clearly either one device does not have an adequate operation supply voltage because it requires a greater difference, or there is an excessive resistance in a connection, which might even be in the common side of the circuit. Which was not ever mentioned at all.
So while a PCB Auto-router can work very well with a net-list and drawings of blocks, I find using it for diagnostics and functional evaluation much less convenient.
So the very first question is between which points is the voltage drop, and the second question is how much voltage drop between the various connected points. Knowing that information will make finding the cause a simple task. Without that information, the answer is already provided in the third sentence.
I'm making a music box. There will be music in the card reader and when we read these cards with the RFID reader, the SD card in the DFPlayer Mini will play music and the engine will run while the music is playing. My Arduino code is ready for this. when i set up my circuit i get 4.20 volts from where i need to get 5 volts i get 2.50 volts from where i need to get 3.3 volts.


I want to play music from a DFPlayer Mini with an RC522 RFID card reader. When I set up the circuit on the plate, I get a voltage drop, I don't know why.

I use a 5 V to 3.3 V AMS1117 voltage regulator with 10 μF on the input and 10 μF on the output.

Normally I was going to feed it with a TP4056. I would switch my circuit with a switched potentiometer as seen in the top left, but I get a voltage drop.
 

ElectricSpidey

Joined Dec 2, 2017
2,879
Provide a block diagram of the power distribution of your system.

Include the power source, and the utilization of that pot.

Show where you are getting what voltages and what you expect.

Also reading the sheet for that charger it states that the output voltage is fixed at 4.2 volts. (which is below what is needed for the 117)

I would not recommend using a battery charger to supply power for this circuit.
 
Last edited:

MisterBill2

Joined Jan 23, 2018
19,351
OK, now part of the problem is clear, which is in a few places. First, that voltage regulator will never increase the voltage above the input source voltage. For such a regulator the supply voltage MUST be at least 2 volts higher than the desired output. So that is the second place with a fatal problem. Next, a digitally controlled potentiometer will not work as a power switch. It is for adjusting the amplitude of an analog signal. So it is not able to deliver any power, which is a second fatal problem.
The fact that the planned power source is not intended to be a power supply , and does not provide enough voltage, nor does it have adequate filtering, is the initial problem.
Five volt regulated power supplies are very, but that might not be an adequate input voltage for the 3.3 volt regulator. There is no need for a battery charger to have a noise-free output voltage, and so that battery charger will deliver noisy power in addition to being an inadequate voltage..
There are logic controlled power switches that would work, while a logic controlled variable resistor will not work as a power switch.
 
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