Battery-board-BMP085 is also based on our multipurpose Battery-board platform. This version includes a BMP085 dual pressure-temperature sensor made by Bosch and is able to measure pressures in the 300-1100 hPa (+9000 to -500 m above the sea level) range with a maximum resolution of 0.03 hPa (0.25m). This sensor also measures temperature from -40°C to 85°C with a ±2°C accuracy. Battery-board-BMP085 is perfect for measuring altitude and barometric pressure in weather monitoring applications.
Figure 1 : panStamp Battery-board-BMP085 for wireless applications
If you are assembling this board by your own, remove R3, marked with the label "DHT 10K". Once assembled, you need to download Adafruit's BMP085 library for Arduino (thanks Adafruit team!). Then you will have to program a panStamp with our sample temphumpress application compiled with the TEMPPRESS definition enabled from sensor.h:
By default, temphumpress takes Vcc as the actual battery voltage. However, all battery-boards have Analog 7 pin (panStamp 12th pin) directly connected to the battery. When using this application on a Battery-board, we advise enabling battery monitoring via the Analog 7 pin. From temphumpress.ino we have to uncomment the VOLT_SUPPLY_A7 definition:
Figure 2 : Base-board-BMP085 with panStamp and dipole antenna
Connection between panStamp and BMP085 sensor is shown in the following picture:
Figure 3: Wiring diagram between BMP085 and panStamp
Firmware-side, when programmed with our sample temphumpress application, the board periodically sends temperature/pressure readings according to the value programmed in the TX_INTERVAL register, saved in EEPROM. This interval is 255 (0xFF) by default in "fresh" panStamps so you will need to program your desired interval after programming the module for the first time. After transmitting the reading, the panStamp enters the sleep mode, disconnecting most peripherals until the next transmission and hence drastically reducing the current consumption.