The gas meter application utilizing an embedded system promises to become a widely used integrated solution. These will make use of integrated microcontroller units (MCUs). I recently visited a tradeshow and saw an intelligent gas meter embedded system (Figure 1). This device has applications in controlling gas flow (industrial, commercial, and medical applications), controlling air flow (HVAC), and detecting dangerous concentrations of toxic or explosive gases (mining and firefighting).
An engineer in charge of the development of the intelligent gas demo board told me about the board's basic architecture. It is interfaced with an OMRON gas sensor and can read/write and display various parameters on the LCD showing gas concentration values. It can indicate when the values reach dangerous levels. The demo board also manages maximum demand calculation and communication with dual interface EEPROM (RF and I2 C interface). Also, the demo board supports a sub-GHz RF module.
The WMBUS protocol stack is running on the low-power STM32L MCU that is available on the board. This allows management of the gas concentration data. Moreover, it's possible to transmit the data via the communication module in wireless mode. In actual use, the system could be inserted in a box with suitable ports to permit gas influx. Figure 2 shows a prototype version — built in a clear box for demonstration purposes.
The demo board also has provision for controlling a motorized gas valve with motor drive circuitry. This interesting solution (Figure 3) was presented along with the gas meter system.
In this demo setup, the motor drivers that manage the air pressure in the tubes are driven by an MCU (once again, the STM32L). An ultrasonic sensor/transducer senses the height of a floating ball, and the MCU turns on the corresponding row of LEDs, which can be seen in Figure 3.
Connectors for external seismic detectors are provided on the demo boards for future use. In practice, you would attach MEMS accelerometers. You could then monitor and sense vibrations indicative of an earthquake and shut off the appropriate gas valves.
By working together, the two companies have created an IT-based intelligent metering device. This new technology would significantly contribute to energy savings when used as part of an HVAC system. Here's a look at the individual pieces and the completed assembly.
The intelligent gas meter system is an interesting example of electronic control of the air quality in a wide environment where this control is required. This is a very promising idea for big companies that must manage things like the air flow in their production facilities. What do you think of this intelligent meter gas control? Do you think it provides a useful solution for monitoring dangerous gases in industrial or commercial areas and controlling air flow? What do you think of the seismic detector option?