User Manual

MPR/MIB User’s Manual

Wireless Sensor Networks

Doc. # 7430-0021-06 Rev. A Page 15

4 MPR500/MPR510/MPR520 (MICA2DOT)

4.1 Product Summary

The MICA2DOT is a Mote designed for applications where physical size is important. Like the

MICA2, these are available in three models according to the frequency of the RF transceiver: the

MPR500 (915 MHz), MPR510 (433 MHz), and MPR520 (315 MHz). The Motes use the

Chipcon CC1000 FSK-modulated radio. All models utilize a powerful ATMega128L micro-

controller and a frequency tunable radio with extended range. The MPR4x0 and MPR5x0 radios

are compatible and can communicate with each other as long as the “x” is the same number.

Figure 4-1. Photos of the MICA2DOT shown next to a US quarter: a) Top-side and b) Bottom-

side. Typically the MICA2DOT has a 3 V coin-cell battery holder attached to the bottom-side,

but it has been removed to show the details.

4.2 On-board Thermistor

The MICA2DOT Mote has an on-board thermistor (Panasonic ERT-J1VR103J) which is a

surface mount component. It is on the ATMega128 side of the board at the location labeled

“RT1.” Its output is at ADC1 and is enabled by setting PW6 (PC6/A14) to “LO” and PW7

(PC7/A15) to “HI.”

The Mote’s ADC output can be converted to degrees kelvin in the 273.15 K to 323.15 K (0°C to

50 °C) range using the Steinhart-Hart equation, which is a widely used third-order

approximation.

)(lnln

)(

thrthr

RcRba

where:

( )

ADCFSADC

ADCR

thr

−

and a, b and c are called the Steinhart-Hart parameters with the following values:

a = 0.00130705

(a) Top-side

(b) Bottom-side

Atmel

ATMega128

Chipcon

CC1000