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 a RTC (real-time clock). RF communication is an increasing requirement for gas and water meters, because of the increasing availability of AMI (advanced metering infrastructure) 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 (HAN). This increased connectivity also requires increased security. The microcontrollers used in gas and water meters require ultra-low power features, often with integrated LCD segment drive capability.
Features and Benefits
- picoPower® Technology
- Active mode using 90µA/MHz
- Full RAM retention uses 1.5µA
- 4x40 Segment LCD Controller
- Hardware Crypto block
Gas and water meters utilize a variety of parameters and techniques for flow metering. Examples include turbine, 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. Systems may have dual clock inputs. One for a high-accuracy main clock used for timings in metrology and a second clock input for a 32KHz RTC (real-time clock). For Smart Meter and Smart Grid implementations, RF is the communication medium of choice to connect to the home-area network to an advanced metering infrastructure.
Learn more about the Atmel® solution Application Notes, Devices, and Tools and Software.