Metering

Gas and Water Meters

Gas and Water Meters

Unlike electricity meters, gas and water meters are battery-operated, so power efficiency is a key requirement. Gas and water meters provide fluid measurement, data display on a small segment LCD, and real time clock (RTC).

RF communication is an increasing requirement for gas and water meters, because of the increasing availability of AMI architecture, with the Smart Electricity Meter often acting as the gateway to the utility for meter reading. Gas and water meters will communicate to the Smart Meter over the Home Area Network. This increased connectivity also requires increased security.

The microcontrollers used in gas and water meters are generally 8- or 16-bit microcontrollers with ultra-low power features, often with integrated LCD segment drive capability.

Features and Benefits

  • Potentially best-in-class embedded 12-bit ADC and analog comparators provide analog peripheral support
  • Power-efficient solutions support battery-operated products
    • 1 µA Watchdog and Brown-Out
    • Atmel® picoPower® technology offers industry-leading solutions for extended battery life
    • Event system to allow measurement whilst CPU in SLEEP modes
    • Support true 1.6V operation
    • Lowest power 32 kHz Crystal Oscillator giving 650nA RTC
  • Option for embedded display controller
  • High EMC performance reduces the need for external protection
  • ±1% internal oscillators, enable communications to run from internal oscillator (RC)
  • Hardware authentication products with ultra-low standby current coupled with onboard microcontroller encryption enhances security for networked applications.
  • Atmel RF Transceivers offers best-in-class power consumption.
  • New single-chip Atmel ATmega128RFA1 combines a microcontroller and RF transceiver for efficient BOM

Unlike electricity measurement (voltage/current), gas and water meters utilize a variety of parameters and techniques for flow metering. Examples include turbine and pelton wheel, optical acoustic doppler, thermal mass, vortex, magnetic, ultrasonic, and coriolis flow meters. These different solutions are represented by the metrology sensor, shown in the block diagram. Analog-to-Digital Converters (ADC) and Digital-to-Analog (DAC) can both be useful peripherals embedded in the microcontroller to facilitate flow measurement.

Flow meters are battery powered, and require power-efficient solutions that can support up to 20 years of operation without battery change.

LCD support is an important requirement. This capability can be driven serially with chip on glass, but must often be integrated into the microcontroller. Essential peripherals include serial communications and, frequently, security through encryption. Dual clock input for high accuracy main clock (often used for timings in metrology) and second clock input for 32KHz for RTC.

For Smart Meter and Smart Grid implementations, RF is the communication medium of choice to connect to the HAN to support AMR.

Products

Microcontroller Hardware Security RF Transceivers
AVR Solutions 8- and 32-bit Microcontrollers

ARM-Based Solutions 		Hardware Security Solutions Single-chip (Microcontroller and Transceiver)
Transceivers
ZigBit Modules

Learn more about the Atmel solution Application Notes, Devices, and Tools and Software