Unit VMeter is a voltage sensor capable of real-time voltage monitoring. It uses a 16-bit ADC converter ADS1115 and communicates via I2C (0x49). To ensure measurement accuracy, a built-in DC/DC isolated power supply is provided, and the I2C interface is electrically isolated using a low-power isolator CA-IS3020S. This prevents noise and surges from the data bus or other circuits from entering the local ground terminal and interfering with or damaging sensitive circuits. Each Unit VMeter is individually calibrated before leaving the factory, with a maximum measurement voltage of ±36V, an accuracy of 1% of full scale, ±1 digit.
Note
Calibration Parameters
The EEPROM (0x53) has built-in calibration parameters from the factory. Do not write to the EEPROM, otherwise the calibration data will be overwritten, resulting in inaccurate measurement results.
Features
±36V range
16-bit ADC conversion
Resolution: 1mV at ≤16V, 7.9mV above 16V
Accuracy: 1% of full scale, ±1 digit
LED power indicator
No recalibration required (EEPROM pre-written at factory)
Built-in CA-IS3020S isolation chip for anti-interference
Isolated DC-DC
Isolation withstand voltage up to 1000 VRMS
Development Platforms: Arduino, UiFlow (Blockly, Python)