ESP32 Metal detector

[ripper121]

Any news?

[moodz]

It’s on my list .... been working on this other project http://www.geotech1.com/forums/attac...2&d=1545469525

[zero48]

Posibility of increasing sensitivity and LION Power supply

Hello,

I hope this is still alive. Please correct me if I'm wrong . Basically the Circuit send a "tunned frequency" pulse by ESP32 (PWM, Which easily can go further than 1MHZ, but we are using low freq. here ) and the reply "listened" by tunned RX coil would change Audible tone frequency depending the Medium (metal/no metal) and this action is done by RX section then is fed to a 12bit ADC channel of the ESP32 (Also controlled by sensitivity Potentiometer R30 ) which BTW this ESP32 ADC linearity is not that good unfortunately . I think there is a way of making this more sensitive which ( I guess ) may work for deeper distances.

I'm working on a circuit for another project (not metal detector related) with HX711 24bit sigma/delta ADC with I2C which it may increase this sensitivity of a particular tunned frequency while Also get rid of most of the OPAMP that Feed the ADC channel on GPIO34.Said that I think would reduce the actual noise picked up by these OPAMP.

Regarding the question About the Power supply I think would be cheap introduce a 3.7v Power supply with a boost converter and charging BMS circuit.

May be I'm daydreaming but I think in my opinion this still can be upgrated.