Over the last couple of months I’ve done quite some research on the kind of display I want for showing the information related to the electrical system. The Volvo 240 converted by New Electric has an EVIC display.
Nicely integrated and at that time pretty much the only thing for sale. However, brightness and viewing angle were not ideal.
Another candidate was the Opus A3e touch from Topcon. It looks like the one below.
And this is what the information on the screen could look like.
The software to design the graphical user interface unfortunately was not very intuitive.
Then we took a look at the corner of the Raspberry Pi, a compact mini computer that runs a Linux variant. So I picked up some dashboard stuff to experiment.
I want to keep the original speedo with some updates for the conversion to electric. The old temperature meter becomes an econometer and the tankmeter will show the ‘state of charge’. Furthermore I’m going to replace the Oil and Amp light since it is not allow to re-purpose them with the old text and a new meaning. I already found a nice LED with a battery warning symbol that fits.
Next to the original speedometer I want to have a screen that shows the electric vehicle related information. I like the approach of the Volvo 240 and add it under the bump. For the Raspberry Pi a nice 5″ TFT touchscreen is available with a good brightness and viewing angle. So I created a dummy.
That could work out pretty nice. I can even keep the original trim below. Question is: How about the line of sight while driving?
Hmm, far from ideal. Due to the fact that I’ve installed front seats from a Volvo 164 you are sitting quite close to the steering wheel but still not great. I also did a test with an actual screen using my phone.
Too much hidden behind the steering wheel. A little more to the right is better in my view.
The bump would become quite wide in that case, but it should be possible.
So I bought a Raspberry Pi and a screen to give it a try.
And it works out pretty nice!
Next challenge is how to make sure I can present the relevant information on the screen. Programming from scratch in Python is out of my league. Therefore I explored concepts that I could potentially use. I found the following options:
Runs on a Raspberry Pi with a hat/extension that allows you to plug it into a CAN-BUS network.
More info and details on carberry.it
This is more elaborate that the above since this hat/extension for Raspberry Pi not only has a CAN-BUS component but also a 4G modem.
More info and details on autopi.io
For these type of of the shelve solutions it can be a challenge to represent the data related to my electric systems. However, linking a CAN-BUS hat to the Raspberry Pi myself and then developing an interface from scratch is also too complex for me.
ECU Master ADU (Advanced Display Unit)
Mischa had the ADU from ECU Master and suggested to use that screen. It’s a robust display from the autosport scene.
It’s available in both 5″ and 7″.
In addition to the CAN-BUS connection, it also has 15 programmable LEDs, 8 analog inputs, 8 digital inputs and two outputs. In addition to display, it is also a PLC for, for example, doing some calculations.
There is software included to create the screen layouts. On the advice of Martijn (of the Volvo 240 Classic Electric) I gained some inspiration from the Volvo C30 electric. There, the charging screen looks like this.
In no time I had that kind of recreated.
But (how) does it fit?
A promising option! It’s much more robust that the Raspberry TFT but as a result also bulkier. I created a dummy using the screen Mischa had. Building on the idea to add the screen under the bump I saw two options:
1) Adding the screen above the chrome trim and heighten the speedometer to keep them aligned at the top.
2) Keep the speedometer at the original height and add the screen ‘in’ the dashboard and interrupt the chrome trim.
For the second option the line of sight could be sub-optimal. In both cases I’ll have to move the heater controls. Paul shared a nice example of an Amazon dash with an extended bump.
Other options / ideas were a pop-up display.
Or perhaps using a dash from a PV since it already shows the entire speedometer. Or perhaps very straightforward position it in front of or on top of the dash like you position a 123GT tachometer.
In all cases the 7 inch version is too large. Furthermore it is a supporting / secondary screen and does not need to present that much information to the driver. And like Erik concluded, since the 7″ and the 5″ both have a 800×480 resolution the pixels on the 7″ might be too large. Last but not least the 5″ has the best brightness. So I continued using a 5″ mockup.
And decided to use the ADU and bought 5″ version at/via Garage71.
And tried it in the dash I had still laying around to experiment with.
Perhaps a little more towards the edge, but looks like a very nice option. Or perhaps fully on top?
Since the dash pad in my wagon was damaged as well anyway I did another test.
That surely is my preference! What do you think? On top of the dash or a little lowered? Comments and suggestions are welcome.