“Previously I had introduced simple raspberry pi (Hereinafter as RPI) operational status indicator circuit.
This time, Ill explain some more useful indicator circuit for RPI running as headless (without monitor) manner.
The circuit above shows CPU temperature into 4 different levels such as:
- Green LED turned on when CPU temperature is within 30~39 degree
- Yellow LED indicates temperature is increased in range of 40 to 45 degree
- 3rd Red LED shows CPU become a little bit hot by reaching 46 ~ 49 degree
- Another Red LED will blink when temperature is exceeding more than 50 degree
The above CPU temperature ranges are my personal design concept (Other temperature ranges can be configured by changing test conditions of python program which control this circuit).
By using this circuit, you are not necessarily executing vcgencmd measure_temp command frequently on console terminal.
This circuit shall inform current CPU temperature continuously and conveniently.”