Mini-General Purpose (GP) Wireless Sensor board

The Mini-GP is an ATTiny85 based low power sensor board combined with a 433 MHz transmitter. If you are interested in playing with wireless sensors this is an inexpensive and easy way to get started. Because they are ATTIny85 based they are a little more difficult to program than their bigger brother the GP3 (no monitor or boot loader) but still simple once you get the hang of it. I have used both the USBTinyISP from AdaFruit (TM) and the Tiny Programmer from Sparkfun (TM) to program them and the ATTINY85 (External 8MHZ clock) board package in the Arduino IDE (TM). While they are not as flexible as the GP3 board they are much smaller and less expensive. One analog/digital line is brought out to the connector and pads making it easy to connect to your sensor of choice. There is also a TO-92 mounting area for a DS18B20 digital temperature sensor IC. (See Note below.)
The Mini-GP is designed as a low power, battery operated, sensor that sleeps most of the time and wakes up once per “Interval” to send it’s status. If you are acquainted with the Arduino environment and would like to build your own custom wireless sensor this is an easy way to start. I have Arduino sketches available that demonstrate how to use the Mini-GP to communicate with an assortment of different sensing elements like: DS18B20 digital temperature sensor, tilt switch, moisture sensor, float switch light sensor etc. Use the sketches as is or adapt them to your custom sensor and your special needs. Contact me for schematics and sketches or for more information.

Note:

The internal resonator frequency drifts with temperature and battery voltage, it is necessary to use an external crystal to maintain reliable transmissions.   Additionally,  I use one pin to power the sensor on and off to extend the battery life and a pin to transmit data so we are down to only one sensor input. While the transmission protocol supports up to 5 sensors per node, the Mini-GP only supports one. The Mini-GP board is designed to work with a 3.0v CR2032 coin cell battery that should keep your sensor running for approximately a year. (Assumes the default reporting interval of approximately one transmission per hour).   The Mini-GP typically draws about 4.6 uA while sleeping.

The Sensible Living Receiver and Desktop application (sold separately) are designed to work with the Mini-GP wireless sensor board. The Desktop App parses the received message, time stamps it, applies your scaling factor and provides a convenient way to see, monitor and track your sensors.

Also available on this site:

• Receiver
• Mini-Plant Sensor
• Mini-Temperature Monitor
• Mini-Water leak detector
• Mini-Tilt Sensor
• Mini-Light Sensor
• Mini-General Purpose Sensor
• Temperature and Humidity Monitor
• Refrigerator/freezer temperature monitor
• Quad AC Current monitor (monitors up to four circuits simultaneously)
• Wireless MQ2 Combustible Gas sensor
• General Purpose Sensor board
• Motion Sensor
• Range Extender

Arduino Enthusiasts

If you are interested in playing with wireless sensors this is an inexpensive and easy way to get started. These sensors are ATTIny85 based. They are a little more difficult to program than their bigger brothers (no monitor or boot loader) but still simple once you get the hang of it. I use the USBTinyISP from AdaFruit to program them and the ATTINY85 (External 8MHZ clock) board package. Contact me for schematics and sketches or for more information.