June 2005

Digital volts and amps in the dash.

Ben wanted to replace the original analog volt meter with a digital one, but since he is such a tech head he could not just have volts, no, he had to go for amps as well......heh, here is how not to do it!

Ben bought the Jaycar volt/amp meter combo gauge (no link cause keep reading). The first one he got turned off after exactly 2 minutes. He was sure glad he opened it carefully and tested it on the bench first. It got returned and a replacement was sent. It tested just fine. The volts were pretty accurate, but the amps, oh, woe is Ben, the amps measure from 0 to 200, so in order to get the electronics to span that range, they have a resolution of 3 amps, so the meter reads, 3,6,9,12 and so on up to 200. Well, it was not perfect, but he figured it was better than nothing, and he had paid the money, so here goes nothing. Well, after a lot of stuffing around trying to get it to work, Ben found that nothing is pretty much what he had bought. The way the amp gauge works is by dropping a small voltage across a known resister and this gives you the current. The resister is known as a shunt, and the Jaycar one was stuffed. A total waste of time. So he replaced it with one he had bought from Oatley. Of course it was a different value, so he had to re calibrate the meter.

This is a photo of the Oatley one before it got wrapped in heat shrink and stuffed behind the battery. If nothing else Ben will have a good shunt installed for the next amp meter project.

The major downer about the whole project is that you can not see the green LED display in the sun, like even over cast dull days its very hard to see. How ever, on the up side, Ben now know his bike uses around 12 amps driving down the road, so he has plenty of alternator grunt to use with a few more gadgets! Yah!

May 2006

Currently, the dash board lay out is pretty much settled. It consists of a 4 line 16 character back lit LCD display that is driven by a PICAXE microcomputer. Ben wrote the software himself. On the top line we have air intake temperature (this is just a temperature sensor on a longish lead, so it can pick up the temperature from any location on the bike) and outdoor air temperature. On the 2nd line we have main battery volts, and secondary battery volts. On the 3ed line we have current produced by the alternator and current being used by the bike. On the last line we have the difference of those two currents (this is what is going into the battery, i.e. recharge amps) and lastly a bit of a tongue in cheek theft deterrent. The words "Alarm on" are constantly displayed. The idea is to have some extra data there while riding, and switch the alarm message on when the ignition is off).

Because it is back lit, it looks fantastic at night, and because its a mono LCD, its crystal clear to read in full sunlight. I have a switch to turn the back light on and off as required.

In this day time photo, you can see that I have been riding the bike, hence the intake is still warm. The ign is off, hence the 0.0v for the main battery. The secondary battery was a bit claged, so its very down in voltage, it should read (as the new one now does) about 12.8v when off charge. You can see that I have not calibrated the current sensors. They now read 0.0 A when the motor is off.....notice the double "AA" at the end of the second current, Ben had some screen refresh issues, but some better software coding has cleaned these up now.

This is a photo of the back light connection on the Veypor. This red wire takes the 5v to the LED back light strip. If you feel (as Ben did) that the back light is too bright on the Veypor, then insert a 200 ohm resistor here, and it will drop the light to about half. Ben put a switch across this resistor, when the switch is on, the resistor is shorted out and the light is at its usual full intensity, when the switch is off, the resistor is in circuit and the light drops to half. Ben uses full in town and half when out in the back blocks.

This is a photo showing the Veypor back light at full brightness. Not the position of the switch.

This is the back light at half, note the position of the switch.

Here is a photo showing how well the Veypor fits in the 1982 Goldwing tacho case. You only have to round the corners off a fraction, and the Veypor still fits perfectly in the original case.

This is the top view of the Veypor, sorry about the fuzzy image.

This is how the screen folds out from the main circuit board.

Top view of the Veypor, this is before Ben cut the back light power feed.

This is how the Veypor sits together in its original case. Note the bit of black padding keeping the PCB off the back of the screen. Makes for a nice safe snug fit.

Ben extended all the cables out the back of the Taco case so the original Veypor connectors will just hook into the same places. The white rectangle connectors are a common connector and should be available from your local electronics shop.

This is how the back of the Veypor looks when you open the case. NOTE! You need to open the case if you want to remove the RAM mount. The two nuts are not held captive and they will drop into the circuit board if you don't open the case and take them out.

If you don't want to open your Veypor, it will fit on the bike, it just doesn't look as finished as fitting it into the Taco case.

Here you can see that the mapping device really is a Gameboy. More about this on the GPS page.

How did Ben program the PICAXE when it was on the bike and the programmer is in the house?

Using a video camera to look at the screen and extending the PICAXE programming leads did the trick.

Here you can see what is getting programmed on the PICAXE LCD screen from the house. It was a simple matter from there to set the screen up how he wanted.