RF Power Meter Pictures on M5Stack Arduino CPU Module - K7MDL2/RF-Power-Meter-V1 GitHub Wiki

Picture of the M5Stack based RF Power Meter with DIY Log Power detectors in the small box. The detectors connect to a dual directional coupler chosen for your desired frequency and power handling needs.

Here we see the Calibration Mode screen where we can select one of the 20 values and adjust them. Each value represent 1dB and should be about the total of the coupling factor of the device + added attenuators plus any fudge factor due to cabling, connector and detector linearity and offsets. The goal is to have a total physical attenuation that puts your max power level into the detector around 1dBm (0 milliwatts), the usual upper limit of the modular detectors.