I have been thinking about hacking one cheap Tds/Ec meter, getting signal with a microcontroller to build an IoT fermenter conductivity logger design. When i searched internet found no one intended to teardown one of those. I'm was particularly interested with that design as it had thermometer built-in. Removing the PCB was really easy as it came off by pulling it from battery terminal using pliers. The pcb had no solid bond with the electrodes embeded in the device case, electrodes were touching to pcb. Temp probe unlike you would expect as not extending into the white probe like looking bulgy plastic instead soldered directly on to pcb. when checked NTC with multimeter showed around 10k resistance at room temp. which traces to an unknown ic and then to the HT1621B microcontroller which features very low quiescent and operation current demands. This was a review what electronic component this ec meter and what ic it used. i am planning to take input with arduino in the future.
There is a similar project and he found that data is transmitted via frequency waveforms https://dankar.github.io/hydrowatch/2014/11/20/interfacing-a-cheap-tds-meter-with-micro-controller/
There is a similar project and he found that data is transmitted via frequency waveforms
https://dankar.github.io/hydrowatch/2014/11/20/interfacing-a-cheap-tds-meter-with-micro-controller/