This is a brief description of what was done to tailor the system the way I wanted it. The analogue part of these very cheap systems is actually pretty good. I have never liked the displays and I could not find a neat way to lose the cable. When I fitted one to a friend's Jag (I told him he would hate it and six months later he bought a Mercedes), getting the cable and connector from the boot to the dash was a nightmare. I have already said that I don't like the idea of powering stuff from the lights. The electronics in the car that sense if a bulb as blown is really quite sensitive and it is not a good idea to put an extra load on it. Click on any image to see a bigger version.
This is my display, built to fit into the oddments box. I took the led display from the original and added to two rows of leds as bargraphs. I also used the miniature speaker. The button is a MUTE touch on/touch off.	Another view of the display showing the micro, the speaker at bottom right, and the back of the 'folded' display module.	And one more view of the display.
This is the boot end. The large pcb is the orignal board. There are lots of parts missing because I took off all the bits I do not need, and then traced out what was left. The ribbon cable connects to my board on the right. It just plugs into the old micro socket. You can see the two leds, one indicates that it is working, the other flashes every time it sends a message ie a new distance reading.	The boot end.	I had to write my own code, obviously. The original system had an 11MHz crystal which is the main reason for the shortest distance of around 36cm. Mine runs at 20MHz which lets me get down to around 20cm. I also have an accuracy of 1cm, and the beeps simply increase in speed the nearer you are to an object. I may fit a sound processor so that I can use the sonar ping noise from a submarine (well why not ???). Four wires from the display carry +12v 0v and a current loop for comms. One wire is needed from the reversing light and I added an extra earth due to past problems with my GATSO system.

This is my display, built to fit into the oddments box. I took the led display from the original and added to two rows of leds as bargraphs. I also used the miniature speaker. The button is a MUTE touch on/touch off.

Another view of the display showing the micro, the speaker at bottom right, and the back of the 'folded' display module.

And one more view of the display.

The boot end.