In my project I operate the vin input of my arduino nano from a voltage of 5 volts. The Arduino should communicate with the dfr0768 mp3 module, which according to the data has a voltage range between 3.3 and 5 volts. In my project I feed it from the lower voltage of 3.3 volts. Will it have a communication problem with the Arduino? I was told that it should be checked whether communication between them will be possible in such a situation that one works with voltage 5 and the other with 3.3, can anyone give me a clear answer on the matter?
I understand this, but I asked about my device, which according to the data can work with voltages of 3.3-5 volts, will the communication be good if I operate it with 3.3 and it receives a communication signal from a component that is operated from 5 volts
We understand your question and the answer by Idahowalker is right. It still depends if the the 3.3V device has 5V tolerant pins.
Chips have ESP protection diodes. If you put 5V at a pin, then there might be current from that pin via the internal ESP diodes to the VCC (which is at 3.3V). It is hard to predict what will happen. Perhaps a large current will flow, perhaps the VCC will be lifted towards 5V, causing problems for other devices, and so on, and so on.
My guess is that there is a chance of 1% to 5% that something bad will happen. But if it does, you will have a hard time trying to find it and chips might get partially damaged. A protection resistor in the signal path might be enough to fix it.
What about the signal from the 3.3V chip to the 5V chip ? When the Nano runs at 5V, it want 3V at a input pin. Maybe the chip (running at 3.3V) outputs only 2.9V with a pin.
I understand you understand this but it depends upon many parameters of which much more information is needed that I am not interested in researching. Heck, I've not even had my morning cup of coffee yet.
A 3V3 device can send a 3V3 signal to a 5V device. Got it?
A 5V device may send a 5V signal to a 3V3 device depending upon the 3V3 devices tolerances. If the 3V3 is 5V tolerant then it's all good. If the 3V3 device is not 5V tolerant then the 3V3 device may give up the smoke. Got it?
I apologize that you haven't had your coffee yet... We have lunch here...
Nevertheless, I will ask how should I check if the pins can receive 5 volts? Where can I get this information from?
In any case, I understand that if I run my module with a voltage of 5 volts instead of 3.3 as I wanted then there won't be any problem right? (I mean, this has nothing to do with the fact that it can also work in 3.3 if in practice it will work in 5).
You can drink the coffee and only then answer if that's why I'll get a calm answer...
This is a bad idea. The Vin pin on Nano connects to the on-board regulator, which needs minimum of 6.5~7V to produce a 5V output. With 5V input it will produce only ~3.5V. A Nano runs at 16MHz and is not guaranteed to work correctly below around 3.7V. You should connect your 5V supply to the 5V pin, bypassing the on-board regulator.
In which case you should not connect any of its pins to a voltage higher than 3.3V, otherwise there could be damage. It would only be safe to connect it's pins to 5V if you power it with 5V. No pin of a chip/module should be connected to a voltage higher than the Vcc pin of the module, unless the data sheet says it is safe to to so.
Even if you solve the voltage issues, you should not use pins 0 and 1 of Nano because they are used by the on-board USB-serial adaptor chip. If you try to use them, you may not be able to upload your sketch or use serial monitor, and communication between the Nano and the connected device may also not work. Instead, connect the device to 2 other, unused pins in the Nano and use a Software Serial library to enable these 2 pins to act as a second serial port.
The 3.3V signal from the Tx pin of the device should be high enough for the Nano to read the data. The 5V signal from the Nano pin used as software serial Tx can be adapted to 3.3V using a voltage divider (eg. 22K & 10K) to avoid damage to the connected device.
The devices should have spec sheets. I'd do a internet search using words and see what I can find.
A). Read the spec sheets. If the spec sheets indicate the devices work that way then fine. But for me to just guess how your devices work, won't do it. Afterall if I say yes do it and you do it and your house burns down, who are you going to blame?
B). What happens when you try? Me. I'd try it and see what happens, if it works it works. If it does not work I have spares on hand.
@uriel252 It will make your circuit design simpler and more likely to succeed if you can supply everything with the same voltage. Your Nano can only run at 5V, so if your other components can also run at 5V, your original question no longer needs to be asked.
If you must run the other components at 3.3V, perhaps you can replace the Nano with a similar Arduino that will run at 3.3V. I have never seen a 3.3V (classic) Nano, but there are 3.3V versions of Pro Mini and Pro Micro, which use the same or similar chips. And there is a wide range of Arduino compatibles that run at 3.3V, most of them have significantly greater power and capability than Nano.
The matter is simple, I was worried that the 5 volt linear stabilizer would not be able to withstand too much of a load, so I thought of dividing the load into another stabilizer that I have with an output voltage of 3.3, after your comments I will choose a 5 volt linear stabilizer that canapply a relatively large load
