Chip McClelland worked with SimpleSense to develop our alpha presence sensor, based on the Particle Electron. This carrier board extends the Electron's capabilities for rugged, long term use, indoors or outdoors, enabling you to deploy your IoT device where there is no WiFi and/or utility power.
- Protection against electrostatic and over voltage events. These devices will be used in unprotected environments.
- Enhanced reliability since deployment may be in hard-to-get-to places.
- Local data storage as connectivity is not assured.
- Flexible power options by either utility or Solar energy
Major components include:
- Power - The carrier board controls both the external power source as well as the LiPo battery. This enables power to be applied with a simple push button. In addition, the electron can perform a "hard reset" using a pin that will suspend all power for about 100 mSec. Watch these features in action in the circuit simluation video. An added 5V boost power converter enables a 3.3V and a 5V ic2 bus on the carrier.
- External Watchdog - This device provides an independent way to validate proper operation of the Electron and reset it as needed. As these devices are located remotely, making them as reliable as possible is a must. Each time the watchdog resets the Electron, it increments a counter that can be remotely monitored.
- FRAM storage - A place to store "state" variables so the Electron can pick up where it left off if reset. It also provides a way to recover data if connectivity is lost.
- Temperature sensor - This is important as you may want to put over temperature alarms (Electron is only good to 80° C) or low temp which should suspend charging the battery.
- Protection - All external power and signal lines are protected from power spikes and static discharge. Again, as these devices can be located outdoors, they need protection from the elements.
Chip includes excellent documentation on the Hackster page for Carrier Electron and on Github.
Chip has been building IoT sensors for outdoor use for several years. He developed these requirements after extensive consultation with the Particle community through the Particle Forums.
His main focus has been to help local parks better count and report the cars, bikers, joggers and hikers which use their facilities each day. By giving them an accurate and automatic way to measure park utilization, they can save significant labor costs, get a more complete count and facilitate reporting.
SimpleSense shared similar deploy-anywhere IoT requirements, with robust power management, reliability, and flexible power options for our presence sensors.
Through his business, See Insights, Chip has tested the carrier board in various outdoor locations, on solar and utility power, over the past 9 months. Testing included outdoors, in parks, in the hot North Carolina summer. SimpleSense has also deployed alpha units in various locations, indoors and outdoors, over the past 3 months.