The original GPS receiver, purchased on ebay, just wasn’t up to the task of getting a good GPS signal inside a Raspberry Pi case. The HAB Supplies board has an SMA socket for use with an external GPS antenna which can then be placed in a suitable position in or on (using a magmount antenna) the chase car. For a car especially, where the sky is partially blocked by the roof (and perhaps by a heat-reflective windscreen) this is a much better arrangement.
The board has a couple of other nice features. Firstly there’s a backup battery (supplied) so the receiver will regain lock very quickly after power-up. Secondly, all of the GPIO pins are connected to two rows of holes on the board, making it easy to connect to LEDs, switches or anything else. For my chase car computer, I wanted to connect 2 switches to enable or disable a couple of functions, so this was ideal. Here’s the board connected to a model A:
The yellow/black wires connect to two small and very neat rocker switches bought from Maplin for 99p each. I fitted one into each half of a Cyntech Blackberry Raspberry Pi Case, by cutting (carefully, with a sharp scalpel) the RJ45 aperture (not needed of course as this is a model A Pi). No doubt other cases are just as suitable though ones made from harder plastic will require cutting with a Dremel or similar rather than a knife. This case is nice as it includes an SD card cover – essential for use in a car where the card could get knocked, breaking the card and/or holder. After cutting I glued the switches in place, firstly with some super-glue to get them into position, and then with some hot melt to secure them further. Here’s the outside of the case showing the switches, plus the WLAN adapter and the GPS cable coming out of the case where the model B’s double USB socket would have been:
One switch controls the position uploads to spacenear.us, whilst the other controls streaming to batc.tv.
Lastly, I mounted the Pi camera on the case using a Pimoroni Camera Mount, used upside-down to normal. I’ve yet to install everything in my chase car, and when do I may have to move the camera for a better view, so a permanent fixture can wait.