How to make a Bluetooth low energy (BLE) enabled IoT Wireless Digital Multimeter?
Many products are now becoming connected through the Internet of Things (IoT), including test equipment such as digital multimeters (DMM). Here is a reference design that discusses how to make a BLE enabled IoT Wireless Digital Multimeter.
4½ Digit, 100kHz true RMS, DMM with BLE
Enabled by Texas Instruments’ SimpleLink ultra-low power wireless microcontroller (MCU) platform, the TIDA-01012 reference design demonstrates a connected, 4½ Digit, 100kHz true RMS, DMM with BLE connectivity, NFC Bluetooth pairing, and an Automatic Wake-Up feature enabled by TI’s CapTIvate technology.
Because power consumption is always a concern to maximise battery life, the design incorporates a low-power MCU that helps to efficiently process the RMS calculations as well as transmitting the data. Also, ultra-low-power converters are used to maintain high efficiency in standby mode.
Basic DMM Measurement Modes
The design implements basic DC voltage and current measurement modes as well as true RMS AC voltage and current measurement modes inherent in most handheld DMMs in the market today. Other basic measurement modes (such as resistance, capacitance, frequency, and so on) can also be supported with minimal power consumption by using the features and capabilities of the CC2640 Wireless MCU. For demonstration purposes, four voltage ranges (50 V, 5 V, 500 mV, and 50 mV) and two current ranges (50 mA and 500 µA) are implemented in this reference design.
NFC Enabled Bluetooth Low Energy Pairing
The design features automatic Bluetooth low energy pairing enabled by the RF430CL330H Dynamic NFC Interface, which simplifies the pairing process making it easier for the user to go through a one-step pairing process.
Mobile App for Reporting and Calibration
The TIDA-01012 enables wireless communication of DMM measurement data and calibration constants using the CC2640 Bluetooth low energy wireless MCU.
• 4 1/2 digit, 50K count resolution
• Basic DMM Measurement Modes include Voltage: 50 V, 5 V, 500 mV, and 50 mV and Current: 50 mA and 500 µA
• 18-Bit, 400-kSPS, SAR ADC Enabling
– 50,000 Display Count Resolution
– 1-µV / 10-nA Resolution
– 0.05% DC Accuracy, 3% AC Accuracy at 100 kHz
• Wireless MCU Enabling BLE for IoT Wireless Communication
• Firmware-Based True-RMS Measurement
• Automatic Wake-Up Enabled by CapTIvate
Capacitive Touch Technology
• BLE Mobile Application Pairing Enabled by NFC
• 100+ Hours on a AAA Li-Ion Battery
Click here for the reference design.