Open-Source Power Meter to Estimate the Energy Consumption of IoT Devices Accurately

ZS1100A IoT Energy Meter

ZS1100A is a USB based programmable DC power supply used to power IoT devices that can provide an output from 0 to 6V DC with 2A max current. The current can be captured at 1Msps with a dynamic range spanning from 1uA to 1.5A and an accuracy of 1% +/- 0.2uA across the range. The tool does not use range switching and there is just one continuous range from -0.5A to 1.5A. Irrespective of the output load as the control loop senses both ground and output terminals, the output voltage remains constant.

 

The new IoT power meter that is compatible with Sigrok open-source signal analysis software and the corresponding Pulseview GUI is a successor to the IoT power profiler tool ZS2102A designed by the company previously. It works with the free IoT Power Profiler waveform analysis tool available for Windows-only as of now, and Mac and Linux versions planned with the release of version 3.x. The ZS1100A achieves the high dynamic range using precision analog techniques and Digital Signal Processing.

 

The ZS1100A power can be used to power the profiling of BLE, WiFi, NB-IoT, and other wireless products, get battery life estimation, debug hardware designs, and optimize software and firmware for power consumption.

 

ZS1100A IoT Energy Meter Working

 

The current profile of an ESP8266 Wi-Fi module is captured here. The module wakes up from sleep using an internal timer and GPIO toggling the RESET pin. The GPIO is captured in the bottom chart. The current rises from 16 μA to a few mA in a couple of ms. Then it reaches tens of mA and then a few hundred mA during the calibration. All of these states are captured in a single range with ZS1100A. This demonstrates the dynamic range, bandwidth, capture length, and digital sync feature of the tool. Note how the output voltage remains constant throughout this variation

 

Key Features and Specifications

  • Output programmable range of 0 to 6V with 10mV steps.
  • Source up to 2A max current. Sink up to 0.5A
  • Fast sampling rate of 1MSPS. (For current measurement)
  • Excellent step response of < 2uS.
  • High dynamic range measurement extending from 1uA to 1.5A.
  • High Accuracy of 1% of measured value+/- 0.2uA across the entire range.
  • Resolution better than 100nA
  • Long continuous capture time (24 hrs capture tested)
  • 2 Quadrant operation (V+,I+) & (V+,I-)
  • Supports negative current measurement to account for battery charging.
  • Electromagnetically shielded for excellent noise reduction with an aluminum enclosure
  • 6 Bit Digital IO capture for synchronization within +/-1uS
  • Real-world battery models for accurate battery life estimation.
  • State of the art data compression saves disk space. (24hrs on 10GB)
  • Powered by a 15V/3A adapter and connects to the PC over the USB 2.0 bus for data transfer.
  • Thermal protection to prevent overheating
  • ESD protection on all inputs and outputs
  • OLED display to indicate the voltage, current, status, etc.
  • Free GUI with waveform analysis tools for Windows.
  • Data export to Sigrok/Pulseview for UART, SPI, I2C protocol analysis.
  • ASCII Data export to XML format for use with MS Excel.
  • Conforms to FCC, CE & RoHS standards.​

 

The kit includes power supply two banana-to-alligator clip cables, eight jumper wires for the front-facing I/O, a USB cable, a flash drive with software, and a quick start guide. The power meter is up for funding on Crowd Supply and shipping is expected to begin in mid-October.