tonich:
without max3232 Arduino can't get signal at 3,7 V.
Just connect the router tx to the arduino rx, and connect the the router and arduino grounds together. The arduino probably can read a voltage down to 2.2v or maybe 1.2v on its rx pin.
tonich:
without max3232 Arduino can't get signal at 3,7 V.
Just connect the router tx to the arduino rx, and connect the the router and arduino grounds together. The arduino probably can read a voltage down to 2.2v or maybe 1.2v on its rx pin.