Texas Instruments has sponsored the following story
Wireless Gas Sensors with Bluetooth® Low Energy (BLE) can make designing wireless products for environmental monitoring quicker and easier. Texas Instruments' (TI's) Wireless Gas Sensor Platform (TIDA-00056) can accommodate these requirements using very low power.
The TIDA-00056 combines four products to produce a small, reliable platform for wireless gas sensors:
- LM4120 (Precision Micropower Low Dropout Voltage Reference)
- TPS61220 (Low Input Voltage, 0.7V Boost Converter with 5.5μA Quiescent Current)
- LMP91000 (Configurable AFE Potentiostat for Low-Power Chemical Sensing Applications)
- CC2541 (2.4-GHz Bluetooth® low energy and Proprietary System-on-Chip)
The possibilities for confined space monitoring such as ship storage tanks, gas storage tanks or even landfills are endless. You can monitor top level gases such as hydrogen sulfide (H2S), middle level such as carbon monoxide (CO) and lower level gases such as methane and pull all of the data into a central location, wirelessly. The Gas Sensor Platform Reference Design provides the details you need to get started.
Figure 2 - Gas Sensor Solution with BLE
Coin cell battery for operation
A coin cell battery is all that is required for this low power, sensor design platform. No more AA batteries or recharging required. Firefighters and first responders can easily carry them to check carbon monoxide or carbon dioxide levels in an area of concern.
Recognize and process data for numerous sensors on one interface
The LMP91000 supports 3-lead amperometric cell and 2-lead galvanic cell electrochemical sensors from vendors such as Alphasense, City Tech, and Winsen. It can easily change between 2 and 3 lead sensors. See the schematics for more details.
This leads to a wide array of gases that can be detected such as:
|
|
Figure 3 - WEBENCH Design Center
WEBENCH® Design Center has the tools to help you produce your design faster by following a few easy steps. There is also a quick tutorial to get you up and designing quickly. You can tailor settings for a specific sensor or chose from one of the many sensors with preloaded settings.
Once your design is complete you can simulate its operation and record data to ensure the accuracy of your design.
Pre-built, open source apps, firmware & software for BLE connection to iPad 3® or iPhone 4S® or later versions.
The video below demonstrates the system taking readings from the CO-AF and O2-A2 sensors from Alphasense.
You can download the open source TI Gas Sensor App from iTunes and then plug in one of those two sensors to begin taking readings.
If you wish to monitor other gases, you can choose from a wide array of sensors from Alphasense, City Tech or Winsen. Then use the open source apps, firmware and documentation to help you make changes and implement your own custom app. The tools are at your fingertips: Gas Sensor EVM tools, LMP91000 and the Gas Sensor Platform Reference Design documentation.
Uses I2C interface for self-calibration and state-of-health monitoring
By sending signals to the sensors and taking internal readings, self-calibration is possible. It also indicates when the sensor is not responding correctly or needs to be replaced.
The LMP91000's adjustable cell bias and transimpedance amplifier (TIA) gain are programmable through the I2C interface. This allows for adjustments of parameters for various toxic gas sensors. For instance, adjusting to detect ammonia would allow your monitor to sense gases from farm animals or even your pet cat.
Figure 5 - I2C interfaces with controller
Complies with FCC and IC regulatory standards
Whether you want to monitor gases in industrial plants, hospitals, healthcare facilities or households, you need to build a FCC and IC compliant system.
Building your system using TI's compliant components ensures that your end products are also compliant without further approvals or processes. This can lead to a quicker time-to-market.
Applications include:
|
|
Texas Instruments has sponsored promotion of their industrial communications solutions on ENGINEERING.com. They have no editorial input to this post - all opinions are mine. – Christine Halsey