ORP is something you might want to monitor if you are using ozone or if you simply want to monitor the general health of your tank.​ The sensor generally has a small PCB which is mounted in the sensor module and a probe for the tank water.
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The PH sensor is an Analog sensor and can only be conected to one of the Senosor module analog ports.
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Here is how to set one up....
ORP Sensor
Analog sensor
An ORP (Oxidation-Reduction Potential) sensor measures the water's ability to break down contaminants, indicating overall water quality in a reef aquarium. It consists of a measuring electrode and a reference electrode that detect the voltage generated by redox reactions in the water. A higher ORP value means strong oxidation (better water quality), while a lower value indicates reducing conditions. ORP sensors help monitor the effectiveness of filtration, ozone systems, and overall tank health.
Hardware conection
How its conected
The PH sensor needs to be connected to one of the analog ports in the sensor module, each port can supply either 5v or 3,3v to power the sensor. For the signal there is a 3 port teminal, the center port is Ground then either side are the Signal pins. Signal can either be sent directly (DIR) to the ESP32 or via a voltage divider (DIV). The ESP32 can only read analog volages up to 3v so if you have a sensor that outputs more then you will need to use the divider.
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Here is an example of how to use the divider:
5v analog output form sensor reduced to 3v for the esp32. R1 = ?Ohm R2=?Ohm
Software setup
Checking the Code
Analog sensors require a little more setup on the Software side, you will have to enter a few details and do some calibrations to get it working corectly.
Setup the code:
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Calibrateion:
Links
Here are a few links to where you can purchase your sensors, click the link depending on your location.
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Worldwide link generally takes longer to be delivered but is a little cheaper. Better if you want to bulk order.
Full disclosure: some of these links are affiliate links, clicking them and purchasing though my links helps me support the project.
Worldwide
Worldwide Link
USA
USA Link
UK
UK Link
Europe
Europe Link