The system will be controlled by an MSP430F5510 microcontroller. This microcontroller was selected due to my previous experience with MSP430 microcontrollers, and for its memory size and peripherals. The MSP430F5510 is a 16-bit microcontroller featuring 32kB of program memory, 4kB of program SRAM, two timers with multiple compare registers, a USCI module supporting I2C, SPI, and UART, a 10-bit ADC, comparator module, and USB functionality.  These features will all be utilized in the final project, with applications including reading the battery voltage, interfacing with external memory, the GPS module, LCD, RF transceiver, and PC, and generating the transmit analog waveforms. The test board provides access to the four main I/O ports, JTAG and Spy-Bi-Wire programming ports, and necessary support components and connector for USB. The board also includes a button and LED for basic user interaction. The schematic for this test board is shown in Figure 1, and the board is shown in Figure 2.
As of 3/16/2012, the parts have been received for the USB connector, and a 24MHz crystal. By holding down the PUR switch (lower left of the board) while inserting the USB cable, the MSP430F5510 bootloader is initialized, allowing new user firmware to be loaded on. The firmware can be loaded through the firmware upgrade example program, found here. The firmware must be in the TI-TXT format. Instructions for generating this output from CCS can be found in the User's Guide. The MSP430F5508 test program was recompiled using this output format and loaded via USB using the example program, confirming the correct operation of the USB bootloader.
- 1.0: Initial release
- 1.1: Added diode between USB 5V and VBUS
Eagle schematic + board file + Gerbers can be found here: http://rev0proto.com/files/MSP430F5508_Breakout.zip
Bill of Materials
|Part||Quantity||Unit Cost||Total Cost||Source|
|USB Micro B Connector||1||$0.87||$0.87||Digi-Key|
|PMEG3020ER 30V 2A Schottky Diode||1||$0.48||$0.48||Digi-Key|
|0603 Capacitor||14||$0.0096||$0.13||eBay - mib_instruments|
|0603 Resistor||8||$0.00294||$0.02||eBay - mib_instruments|
|SMD Tactile Switch||2||$0.1198||$0.24||eBay|
|SMD 24MHz Crystal||1||$1.43||$1.43||Digi-Key|
|0603 Green LED||1||$0.11||$0.11||Digi-Key|
|0603 Red LED||1||$0.13||$0.13||Digi-Key|
|Total Unit Cost||$11.16|
- Texas Instruments Inc., "MSP430F550x MSP430F5510 Mixed Signal Microcontroller," March 2011. [Online]. Available: http://www.ti.com/lit/ds/symlink/msp430f5510.pdf. [Accessed 5 February 2012].