Are you using the second Arduino for the SMeter?? If so, then the speed is based on how the code is written and the communication mechanism with the Nextion.? I have replacement firmware for the second Arduino that makes the SMeter much faster (but if you turn on the FFT function is gets slow again).? My project can be found at?
If you have not already used the second Arduino, I highly recommend you first get things working with Dr. Lee's original code, using his documentation before trying my new version.?
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Dennis WC8C
