Automotive current monitor

If you’ve ever had a car with an electrical system problem you know how hard it can be to pin-point the source of your woes. Here’s a hackery solution that uses a diy PCB to monitor the current being drawn off of the alternator.The sensing is provided by an Allegro ACS758 integrated circuit. This chip measures current up to 150A and outputs an analog signal that can be measured by a microcontroller. In this case an AVR ATmega8 measures the signal and spits the info back to a PC via the serial port. This data can be graphed to help locate when too much current is being drawn for the battery to remain charged.

Check out that CNC milled PCB, what a beauty!

[Thanks Joshua via Elektronika]

Cheap cup holder laptop tray

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[Michael Davis] sent in his homemade laptop tray. He does a lot of traveling in his Toyota Tacoma and was looking for a good way to mount his laptop inside. Unfortunately, [Michael] soon discovered that commercial laptop trays can be very expensive and difficult to install. He saw an opportunity in the empty cup holder in his car. Fifteen dollars worth of PVC pipe fittings and a piece of plywood later he had a laptop tray.