The supply voltage is 8.2 volts from two 3.7 volt 18650 batteries.
The case holder has an on off switch and they are in series.
I have a step down voltage converter of 3.3 volts on there. So the supply voltage to the hc-12 and arduino is 3.3 volts.
I have the arduino plugged into USB only for troubleshooting purposes so I can view results on the serial monitor.
The battery power switch was on the on position when I unplugged the USB connection from the PC. I’ll try the grounding idea to see if that’s the issue.
I did change both the receiver and transmitter to FU2 power saving mode to save battery life and reduce power consumption. The HC-12 manual is attached. For reference my delay time of 1000ms is sufficient for transmitting data.
It works fine when connected to PC. I have the receiver end powered with a DC variable voltage testing power supply and sometimes a 6 volt solar panel. I also have a 3.3 volt step down converter on the receiver side.
The weird part is sometimes I power the transmitter side with a 5 or 6 volt solar panel and the receiver side with a 6 volt solar panel and I know I am getting sufficient current. The arduino lights turn on and also the motors I have on the receiver side move occasionally when the transmitter and receiver are working properly. I took a look at the serial monitor on the receiver end and it seems the analog sensor values that cause the motors to move stop getting sent for some odd reason.
HC-12-Documentations.pdf (282 KB)