Home › Forums › Environmental Sensors › Hydros 21/Decagon CTD: reading error › Reply To: Hydros 21/Decagon CTD: reading error
We’ve just had a failure to communicate with our newest Hydros 21 sensors (likely Gen 2). While I’ve had success setting the address with the b_address_change sketch, my standard Mayfly code can’t talk to the sensor and returns values of -9999. It looks to me like the SDI-12 library has not changed since May 2021 (https://github.com/EnviroDIY/Arduino-SDI-12/).
However, MeterHydros21.h within ModularSensors was updated last month (https://github.com/EnviroDIY/ModularSensors/tree/master/src/sensors) for the new timing requirements of the Gen 2 Hydros 21, and updating that library was what fixed the communication problems I was having.