How does Mica Motes work | Short notes on Mica Mote

MICA mote is a commercially available product that has been used widely by researchers and developers. It has all of the typical features of a mote and therefore can help you understand what this technology makes possible today. MICA motes are available to the general public through a company called Crossbow.

The MICA mote uses an Atmel ATmega 128L processor running at 4 megahertz. The 128L is an 8-bit microcontroller that has 128 kilobytes of onboard flash memory to store the mote's program. This CPU is about as powerful as the 8088 CPU found in the original IBM PC. The communication frequency at which the mote radio operates work is at 40 Kbps.

This low power consumption allows a MICA mote to run for more than a year with two AA batteries. A typical AA battery can produce about 1,000 milliamp-hours. At 8 milliamps, the ATmega would operate for about 120 hours if it operated constantly.

The programmer will typically write his/her code so that the CPU is asleep much of the time, allowing it to extend battery life considerably. For example, the mote might sleep for 10 seconds, wake up and check the status for a few microseconds, and then go back to sleep.

Mica board is stacked to the processor board through the 51 pin extension connector which includes temperature, photoresistor, barometer, humidity and thermopile sensors.

Mica mote was developed into newer versions with the energy conservation, A/D converter and 8X8 power switch on the sensor board.

The mica mote is enclosed in an acrylic enclosure to protect sensors from the variable weather conditions which do not obstruct the sensing functionality and radio transmission.

Mica 2 mote is the later version of Mica mote. It operates in 3 modes based on RF frequency.

  1. MRO400 with 915 MHz

  2. MRP410 with 433 MHz

  3. MRP420 with 315 MHz

There are 3 miniature Mica motes of 1/4 size of normal motes available as MICA2DOT.

Another version of Mica2 mote is also available which use the combination of ultrasound & RF signal developed by crossbow & MIT. This version provides the flexibility to switch between the listener and the transmitter.