Speedo internal wiring

I have finished a little sub-circuit board that links my main uProcessor board to the three displays.
The two lines of pins are for the two 16 x 2 line white-on-blue LCD displays. The connector hanging out the front is for my main display. The red heat-shrunk wires will have a four pin connector on them that connects to the trip reset button and up/down buttons (contrast/menu selections). The black wire with the RJ45 connector (bottom of picture) is so I can re-program the Flash without having to remove the speedo from the car or remove any covers. It will be accessible from underneath the dash once it is installed.
 I'll tidy the wires up and secure them when the displays are in and the layout is locked down. I have yet to connect wires to the DB15 connector that will be secured to the rear of the speedo housing.

Closeup. Thanks to Theo for the fiddly soldering on the two fine-pitch connectors.

Next job is to wire the DB15 then the stressful task of gluing the main display to the front panel (silicone), without getting any bleeding out to the front.

Speedo, ODO and other Gauges

As mentioned earlier in this blog, I have no speedo cable therefore I can not use the original mechanical speedo. One of the many side projects (that most EVers do NOT have to do), is to make a new speedo cluster. The brief is easy - it should show:

• Speed.
• Odometer (distance the car has ever travelled)
• Tripmeter
• State of battery charge
• Instanateous battery current

Fortunately I work in an industry where I have a jump-start on providing these readouts. I guess if I didn't work with this kind of thing I wouldn't have embarked on this little project - but on with the story.
The "smarts" in the dash will provided by the guts of a proto-type of this Control Unit (for the SIMOCO mobile radio). This one is called a 9022, it runs a PIC 18F6627 microprocessor which gives me plenty of Digital inputs, outputs and Analogue inputs.

The other huge advantage of using this as a base is that display drivers have already been written and the development system is already set up and running. It's an area of software projects that I dislike - having to set up new environments and get used to them. While I didn't write the CU software in these products, I was familiar enough with them where my learning curve was quite fast.




The display itself was not big enough for my purposes, but another Control Unit we make (9030) has a much bigger display and uses the same micro (but the circuit board was way too big), so I grabbed the display driver from the 9030 and came up with a single set that runs the 9030 display. (In reality I ended up using the 9030 software and adapted it to the 9022 circuit board.)

The 9022 and the 9030 Control Units.

Here is my prototype - I do not have the backlight connected yet so it's a bit dark under the light I took the photo.

The centre display shown below is about the same height as the width of an iPhone.

I have placed all information on this one display for now, but the final system will have battery and ODO displays on the two 16 x 2 white-on-blue LCD displays either side of this main one. The main display is "transflective" meaning that it can be read in bright sunlight or backlit - essential for the speed indication.

First line is battery current.
Second line is AH consumed from battery. It starts at zero at the moment but when I start using the car and getr used to how much I can use safely, I will rework the software so it show AH remaining.
Lines 3,4, 5 and 6 are speed in km/hr.
Line 7 is distance travelled. This value, trip and AH are all saved when the speed goes from above zero to zero and are also saved each kilometer travelled.
Last line is Trip. Accurate to 10 meters.

I will show how it all fits together into the Vogue orginal speedo housing in the next post.

Rear Chargers

One of the last mechanical type things I have to attend to is mounting the rear battery pack chargers.
I originally intended them to mount on a rail on the rear firewall but there really isn't enough room and I wouldn't be able to see the lights easily.
This arrangement uses the battery straps looped under part of the mount to hold the charger mounts onto the top of three of the battery packs. The inverted 'L'  aluminium will be neoprene rubber lined. I will have to be pretty accurate with the mounting rail widths as there is only 10 mm between packs.

Here is my Sketchup of the proposed mounting scheme.

Close up.

Basically it's four pieces of 12.5 x 20 mm aluminium angle with 3 mm spacers to allow the strap to go though.
I have bought the angle so I'll try to get them done this week at night.

Engine Bay Relays Mounted

The DC-DC Isolator, Start/Run and Fan Control relays are all mounted. I have also updated the control circuit diagram here to reflect the fact that I have moved the Start/Run latching relay to the engine bay. The wiring will be tidied up as it is terminated. The heavy red wire comes from the boot BMS monitoring. The loose wires draping down toward the battery tray will be used to connect to the relays, so I might modify the wiring loom on this side of the car as well - then again I can hide them pretty easily.
The odd looking mounting positions are due to using existing tapped holes that were previously for the ignition coil, starter solenoid etc.

DC-DC Relay

As mentioned many posts ago in this blog, I have two Switch Mode Power Supplies (DC-DC converters) that will supply up to 40 Amps for the 12 V systems in the car. I do not want to connect them directly to the little 9 AH, 12 V battery because if the car is left idle for some time the DC-DCs will drain the 12 V battery.
So there will be a relay in between the DC-DCs and the 12 V Battery. The relay will turn on when the high voltage system is energised.

A Tyco 150 A relay seems to be a good overkill. Seriously - I had it - and it gives me some convenient 6 mm terminal posts to connect things to. The coil doesn't draw any more current than one of those automotive Narva (or similar) 70 A relays.

The two purple wires go to the coil.

I will try to get it mounted and partially wired tonight.

Horn Relay Mounted and Wired

The original Vogue did not have any relays in it. The result that on a wet, rainy night with heater, wipers and headlights on, beeping the horn got no sound at all. The rest of the time they worked fine. Just too much voltage drop in the wiring.

The relay location is just above the left "fender" where the original Generator regulator used to live.
I did something I said I wouldn't do - I modified the Vogue wiring loom.
Not too serious - I removed wires that extended the loom to the Generator. They were redundant and messy. It was the first time I have got greasy and dirty since beginning the re-assembly process. When I unwrapped the loom tape there was lots of oil and grease underneath. They also used black tar tape about every 100cm which made a heck of a mess. The remaining wiring here is original except I removed two large spade connectors and replaced them with 6.25mm spades so that they would plug onto a standard relay.