Picking the right MSP430

Update: This project was completed and published as a Masters thesis (Slides).

Listening to: Into the Light by Philip Wesley on Dark Night of the Soul [Pandora/Instrumental Radio]

TODO: Pick one of 412 MSP430 products for tracking human wrist motion data all day.

Requirements:

1. Needs to have SPI / I2C support.
   1. The Invense sensors we’ve picked run on I2C or SPI. I2C is preferred.
   2. The Memory Chip we’ve picked needs SPI.
2. Needs at least 2KB of internal SRAM. The memory chip has 2 SRAM buffers of 1K each. 2k of SRAM would mean extra space for storing other data.
3. Around 4 – 10KB  of Flash memory to store our program.

Updates:

1. Looked at Shimmer, the product we’ve reviewed earlier. It uses the MSP430F1611. Looks to fit our requirements, however, the MSP430 series comes with 3 different communication modules (USI, USCI, USART) ^a, and this one lack’s *good* support for the I2c and SPI protocols ^a.
2. Grabbed the product brochure from MSP430: http://www.ti.com/lit/pdf/slab034
3. Went through the products looking for 2K of SRAM, and USCI support. See something near the MSP430F247 which has 4K. Also like the F248. The MSP430F2419 looks like the big daddy of the F2xx series.
4. F249 has 2k of SRAM. I think I’ll go for the higher (4K SRAM) so that I can buffer more data, and probably write simpler code.

Meeting Updates:

1. Need some kind of connector to connect from watch to computer. Thinking of a USB Library running on the MSP430. Need to use more of those 64 pins.
2. Some kind of interface for the watch to show that it’s tracking. LED’s consume too much power, which means less for the watch and data logging.

Simple Flow Diagram for the three components. Battery / Power missing.

A: See discussion at http://e2e.ti.com/support/microcontrollers/msp430/f/166/p/124083/444354.aspx