MSP430 IO 16bit Expansion board(shield)


A note on the cost and time estimates.

  • Time = time to draw out the schematic, do the layout and then populate the board. It's also the little things that seem to be the most time consuming and also what seems to not take long until you look at the clock.
  • Cost = cost of getting the boards fabbed(you get 3) plus parts to populate the board. This is the high side. actual cost of the board iteself would be around 10-15.

MSP430 IO 16bit Expansion board(shield)

This is the second shield I've created for the MSP430 launchpad dev boards. This board provides a 16bit io chip that can be set up as either an I2C or SPI, but not both as each chip only provides support for 1 protocol. I've provided a means for configuring the address of the chip if needed, the reset pin can be hardwired or or set by the proc and there are two options for the enable pin, one for 16pin and the other for 20 pin chips to use.

IO chip - MCP23X17 IO expander with serial interface.

  • supports I2C or SPI
  • Configurable interupt output pins
  • Configurable interupt source
  • External reset
  • Low standby current
  • Operating voltages work well with msp430


  • Some uses that I was considering.
  • multiple 4pin lcd controller(HD44780)
  • LED display controller(no pwm though)
  • Keypad input interface
  • rotary encoder interface(using port A and B ints I think this can be done)
  • Expanded inputs for something like comparator devices.(INT triggered)


Is the board big enough for

Is the board big enough for a 12 oz pop can :stuck_out_tongue:

Looks interesting. Any plans on a Motor Driver shield?

Yes it is, and I even made

Yes it is, and I even made it thin enough for the can to breath at the bottom.

Motor driver shields are your thing, when I look at getting one designed(I will need one in the future), I’ll come askin for your assistance.  :)

Maybe I can create an adapter for the current ones that you have.

Wouldn’t it be preferred if

Wouldn’t it be preferred if the motor shield was driven by the line multiplier?