Project Objective:Develop an open source AIS Alarm that alerts sailors that a new marine vessel with AIS is within range
In this post I will describe the hardware to be used for prototyping and why it was chosen.
Starting in the upper left and going counter clockwise:
dAISy Single Channel AIS Receiver - This receiver is inexpensive, reliable, and I have experience with it. It is open source and the developer is open to working with hobbyists on their projects. The antenna is not shown but I can connect to it in my work area and pick up AIS signals.
LM1117-3.3 and 0805 SMD 10 uF tantalum capacitors - I may or may not use a LDO in the prototype but it will be required in the final design. A LDO makes sense when using a radio due to low noise and efficiency is not an overriding concern here. I happen to have these on hand and have used them in the past. I will follow the datasheet for the design which recommends 10 uF tantalum capacitors. The SOT-223-4 and 0805 can be hand soldered and I have adapters for 0.1" connection if needed.
MSP-EXP430F5529 - Almost any LaunchPad for the MSP430 series will do. Another good choice would be the new MSP-EXP430FR2433. It could even be used for the prototyping since it has FRAM and would be easy to port to another part in the FR2xx series.
Piezo-Electric Buzzer - I have a couple on hand of unknown origin. I will use an active buzzer (one that buzzes with just voltage applied) to start due to simplicity. When the final design is done I will select one from a known manufacturer.
Small MOSFET - This will be used to supply 5V to the buzzer. I happen to have BS170 through hole versions on hand but will select a SMD MOSFET for the final design.
LEDs and resistors - I have 5 mm through hole on hand but will look for high visibility panel mount for the final design. Resistors will be 0805.
Button Switches - These are what I have on hand. Will need 90 degree or something different for the final panel mount
Slide Switch - Again, what I have on hand. Will need something panel mounted in the final design. May decide to add a "quiet" switch for the buzzer in the final design (feature creep already?)
MSP430FR2111 - I think this will be the best MSP430 FRAM chip for this project although there are versions with increased FRAM and SRAM if needed. FRAM is an advantage since I need to write quickly and retain the incoming AIS messages when the project is unplugged from it's power supply. There are also sufficient GPIO, timers, and UART. I checked Newark/element14 and they weren't carrying it as I write this - I obtained my samples directly from TI. I previously designed the little board in the photo and had it fabricated at OSH Park so I can use it on a breadboard.