Hello,
i am going to power a module with the arduino 3.3 V pin. The module operates at 2.7 to 3.6 V . It will communicate with UART protocol. That means that it will send data back to an arduino digital pin. As we know though the arduino expects a voltage of 5V at his pins. So my question is what should i use to boost the signals (Tx) voltage? Need explanation about the signal form output.
Try searching your favourite electronic store for;
logic level converter
In my experience with both the various processors use in Arduino and with PICs you can connect a 3V3 serial Tx to an Rx that expects 5V and it works fine.
What are you doing the other way to reduce the voltage from the Arduino 5V Tx to this device's expected 3V3?
Probably no need for a level converter. The Arduino doesn't necessarily expect a 5V signal for high, because logic levels only have to fall with a voltage range. I think the voltage just needs to be above 3V. This answer might be in the Arduino datasheet? Definitely in the datasheet for the underlying ATMega328P chip.
You could use a level converter if you wanted. That would be extra insurance, but it shouldn't be necessary.
The answer is in the datasheet, Electrical Characteristics / DC Characteristics:
high is > 0.6 Vcc (ie 3.0V for 5V Vcc)
low is < 0.3 Vcc (1.5V for 5V Vcc)
Note these values change if powering the Arduino at very low voltages.
So 3.3V is just OK if powered from 5.0V
ok thank you everyone for the info.
You will need a level shifter for the Arduino Tx to sensor Rx. A voltage divider is the easiest, cheapest way of doing this.
wvmarle:
You will need a level shifter for the Arduino Tx to sensor Rx. A voltage divider is the easiest, cheapest way of doing this.
The OP states the 3.3V chip is only transmitting.