https://devzone.nordicsemi.com/f/nordic-q-a/2814/uart-and-arduino-uno-communicationI have a nRF51822 and arduino uno board. Is it possible to connect my nRF51822 uart to the arduino rx/tx, so that i can use it for communication to PC through arduino. The voltage levels in UNO works on 5V p-p and nRF51822 is 3.3 p-p. Will it destroyen-USTelligent Community 13Tue, 17 Jun 2014 06:59:07 GMThttps://devzone.nordicsemi.com/thread/10787?ContentTypeID=1Tue, 17 Jun 2014 06:59:07 GMT137ad170-7792-4731-bb38-c0d22fbe4515:02eae94b-9e1b-43e2-9b68-35d6b6035b87Stefan Birnir Sverrisson<p>Hi</p> <p>The absolute maximum ratings chapter in the nRF51822 PS specifies maximum voltage on GPIO pins to be VDD+0.3V (nRF51 supply voltage + 0.3V), so it is allowed to have your UART peer device to drive the UART with up to 3.9V if your supply voltage to the nRF51822 is at maximum at 3.6V.</p> <p>Section 8.23 in the PS specifies the voltage levels required for GPIO pins, i.e. that input high voltage is detected at VDD<em>0.7 and input low voltage is detected at VDD</em>0.3. So if your supply voltage to the nRF51is 3.3V, then the UART peer device must operate between 3.3*0.7=2.31V and 3.3+0.3=3.6V</p> <p>So, if your arduino has 5V output on UART then you would need a voltage-level shifter circuit to enable the UART communication with nRF51822.</p><div style="clear:both;"></div>