7. Hardware API

7.1. Schematics

To interface new sensors to the WiSense platform or for hardware level debugging, the pinouts and schematics in this section will be a useful reference.

Figure 1 shows the top view diagram of MSP430 board. Connectors J1 and J2 contain many pins routed to and from the MSP430. Vcc and GND on J3 are used for powering up the node from an external source. These two pins also routed to Vcc and GND on J1. They supply power to other boards stacked with the microcontroller board.

If no external power supply is used, the node is powered by a coin cell battery (CR2032). J3 is also the interface for programming the node. Connection to J3 is via a 4-wire cable from TI MSP-EXP430F5529LP LaunchPad. The LaunchPad itself will connect to a computer (host) via USB cable. J4 has the UART interface. J4 connects to a computer (host) via UART-TTL converter having a USB interface. In current version, J4 is used as the gateway interface to host computer. Network status and updates are sent and received on J4.

Figure 1: Top View Diagram of MSP430 Controller Board


Figure 2 shows the bottom view of the MSP430 board. The three big components on the board are (top to bottom): 32 kHz crystal, 40-pin MSP430G2955 microcontroller and 8-pin EEPROM.

Figure 2: Bottom View of MSP430 Board


7.2. Software Interfacing

Code for current version of the hardware can be enabled by defining the compile-time flag WISENSE_HW_REV_6. Please note that previous version numbers were used for prototypes.