I’ve already fitted a Pumpkin Android head unit that has an input for a reversing camera, it’s wired up so that as soon as you go into reverse, the camera powers up and shows on the head unit screen. All’s good.
I’m thinking about fitting rear parking sensors (bloody flower tubs on the edge of the drive). The standard beeping ones are pretty straightforward, however, there’s some on the market that have a little screen (with a digital readout NOT just the coloured bars) as well as the (normally horrible cheap) beeper. I’m trying not to clutter up the dash area with another stick on screen so was wanting to find out if I could somehow connect the output to the head unit?
So Sparky Electronic Wizards, is it possible to somehow fix this up to send the output from the Parking Sensor’s control unit to the video input of the Android Head unit? I’m guessing (Ok, hoping) that it should be possible BUT, then there is the issue of it overriding the rear camera… Getting well past my 12v pay grade.
After a little more creative searching, There is already a ready made solution to this issue, probably easier and more reliable to throw some money at it rather than cobble together something… unless someone knows better!
Several of the generic beeper boxes simply intercept the analogue video from the reversing camera and pass it on to the head-unit having added the extra info to the signal; and while the connectors on the little box are tiny custom jobs, the leads supplied have the usual yellow phonos for the video.
Since your head unit knows about the car being in reverse and sends suitable power to the reversing camera, this might possibly also be used for the beeper box. The beeper I put in my MX5 takes only approx 30mA from the switched 12V without a display, but apparently this goes up to 180mA with a display (I don’t know if this includes display power as well since I’m not using a display with this beeper).
BUT be aware, some cameras are only 5V or 6V and the beepers are usually 12V.
On my Mazda3 the el-cheapo camera (about 1/20th the cost of the proper Mazda version) I bought needed 12V at 60mA, but the Mazda head unit only sends 5-6V and I needed to add an up-converter in this line to power the camera. If your head unit is sending 5V then the up-converter I used might do for the beeper.
And the up-converter is this one. I ordered two, just as well because I received one up-converter and one down-converter both with the same label on their bags but the insides different, oh well.
Rather than use an upconverter, you could do it the old fashioned way and use the 5v line to control a switched relay, which sends 12v direct to the camera.