The store that I purchased this from (for $30), wants to charge $9 for a breakout board for this, which I feel is kind of crazy (with that money, I could add an ATMEGA328 to parse the GPS), so I made a cheap $0.30 breakout board (well components push the board price to 0.50 or 1.00). It has the connections for USART and USB, and I plan to have an RJ45 connector to put this GPS circuit somewhere remote (RJ45 – ethernet connector). Thinking about disguising it in a gum box, but then again, it would be a gum box + ethernet cable coming out of it, so not much of a disguise.
I’ll update the Projects page, but here is the details of the car monitor (which will be similar to my UPC battery backup logging experiment):
– 6 Temp sensors (Engine x 2, Radiator, Transmission, outside, inside)
– GPS (location, speed, time)
– Piezo (maybe alert on high temp?)
– MotionPlus Gyro (sense direction)
– Bluetooth Serial module
– 3.3v system, powered via car battery
I will have the power for the GPS + MotionPlus + BT module controlled using a BSS123 nMOSFET, as explained here. When the car is off (can detect because Alternator pushes battery voltage to around 14.2), it will turn off the non-essential things and enter a sleep mode, where it wakes to determine if it should still sleep. Cars are noisy environments, so I will be using some techniques discussed here to protect the inputs of the ATMEGA328. This project shouldn’t take too long (ha) because most of the framework is there, I just need to add the code to sleep, to use the motionplus, filter the car battery voltage to power my circuit, and to parse the GPS data. Progress!