Description Unit VMeter is a voltage sensor for real-time voltage monitoring. It uses an ADS1115 16-bit ADC converter and communicates over I2C at address 0x49. To protect sensitive circuits and improve measurement stability, Unit VMeter combines a built-in DC/DC isolated power supply with CA-IS3020S electrical isolation on the I2C interface. This helps prevent bus noise, surges, or other circuit disturbances from entering the local ground path. Each Unit VMeter is factory calibrated before shipment. The maximum measurement voltage is +/-36V, and the stated accuracy is 1% of full scale, +/-1 digit. Notes The EEPROM at 0x53 contains factory calibration parameters. Do not write to the EEPROM, because overwriting this data will cause inaccurate measurement results. Features Unit VMeter voltage sensing: real-time voltage monitoring with a maximum measurement range of +/-36V. ADS1115 conversion: 16-bit ADC conversion for high-resolution voltage readings. Resolution behavior: 1mV resolution at readings up to 16V, and 7.9mV resolution above 16V. Factory calibration: each unit is calibrated before shipment, so recalibration is not required for normal use. I2C communication: communicates through I2C at address 0x49. Electrical isolation: CA-IS3020S isolates the I2C interface for anti-interference protection. Isolated power: built-in isolated DC-DC design with isolation withstand voltage up to 1000 VRMS. Development support: Arduino examples, UiFlow1 example, EasyLoader, and Home Assistant integration are available for Unit VMeter. Mounting support: two LEGO-compatible holes help with fixture and prototype installation. Specifications ADC Converter ADS1115, 16-bit ADC conversion Measurement Range +/-36V Resolution 1mV at
