Xh-m608 Manual -
Remove the jumper: You can now power the relay coils with 5V (or 12V, or 24V!) while your microcontroller uses 3.3V. This is . It means your $50 Arduino won’t fry when the water pump kicks in. The manual doesn’t explain why this is glorious – but trust me, it’s the difference between a hobby and a house fire.
The XH-M608 manual is not a document. It’s a dare. It says, “Here are the pins. Don’t die. Figure out the rest.” And that is its beauty. In a world of over-engineered, app-locked, cloud-dependent smart devices, this little blue board is pure, unadulterated freedom. It clicks, it clacks, and it asks for nothing but 5 volts and a little respect. Xh-m608 Manual
These connect to the battery source being monitored. The board draws its logic operating power directly from this terminal, which must stay within the DC 6–40V constraint. Remove the jumper: You can now power the