Yp-05 Pinout

The pins are almost always numbered sequentially in a clockwise direction:

The UART output pin that sends serial data from the computer to the external device. yp-05 pinout

But it had saved three thousand souls. Because in the cold arithmetic of deep space, survival wasn’t about courage. It was about knowing which pin goes where. The pins are almost always numbered sequentially in

This is the classic Arduino error. Usually, it means your TX and RX wires are swapped, or the DTR pin isn't triggering a reset. yp-05 pinout