alexanderfitu
Posts: 2
Joined: Sun Jun 14, 2015 9:45 pm

Raspberry Pi as Motorbike Dashboard

Sun Jun 14, 2015 9:53 pm

Hi All

I have no experience with Raspberry PI but am aware of its concept and have had friends explain how it works.

I would love to setup a Raspberry Pi to replace a motorbike dashboard in its entirety. The plan is a 7 inch LCD connected directly to the PI. It is my understanding that this type of display will show the OS and the Gui (should I choose to have X windows running).

The idea is to have the screen display all paremeters, including

Speed
RPM
Engine temp
Indicator lights, oil pressure lights etc.
and also

use it to control various electrical items on the bike with its GPIO pins.

Is this something that is theoretically possible? I understand that using a large 7 inch LCD essentially means I have to code a program to display these values, as opposed to using a 16x4 LCD display or a Nokia 5110 LCD display, where coding is much easier.

Is this something that is possible

Thanks in advance!

henryhanselscott
Posts: 107
Joined: Sun Jan 18, 2015 1:31 pm

Re: Raspberry Pi as Motorbike Dashboard

Mon Jun 15, 2015 1:58 pm

Probably not directly possible. The pi is strictly a digital device, you can use some timing functions and RC circuits to get some basic not very accurate analog data using a digital port watching for the trip point for the on/off, off/on transition. So you would likely need something along the lines of an Arduino to supplement the requirements of your project. Then you would have to deal with the power sensitivities of the pi and proper shutdown procedures, not just switching the bike off and hoping that all is well the next time you get on it to ride. Not trying to discourage you at all, just letting you know up front that a learning curve is ahead of you. That is not a bad thing, it is exactly what the pi was created for, learning.

Henry

Heater
Posts: 15484
Joined: Tue Jul 17, 2012 3:02 pm

Re: Raspberry Pi as Motorbike Dashboard

Mon Jun 15, 2015 5:50 pm

Given your apparent lack of experience I suggest you don't start with big dreams of ripping out the original dashboard and replacing it with your own creation. There are so many things to go wrong mechanically, electrically and software wise and it's a big project anyway.

Start with one simple thing, build it, test it, tweak it till it works, test it again over the long term. The speedo or the tacho would be a good place to start. With that experience under your belt you will be better placed to see if you want to continue and if so how.
Memory in C++ is a leaky abstraction .

alexanderfitu
Posts: 2
Joined: Sun Jun 14, 2015 9:45 pm

Re: Raspberry Pi as Motorbike Dashboard

Tue Jun 16, 2015 3:58 pm

Thanks indeed.

I don't have experience with the Raspberry Pi, as you say. I do have some electronics experience.

I do understand that what I am trying to undertake isn't going to be straight forward, not to worry, I wont be removing the original dashboard anytime soon. I will work on adding small bits at a time, as you say. Maybe run them in tandem whilst testing.

I see, as you say the raspberry pi is a digital device. I assume then to read sensors that output a resistance value, I would need an ADC to accomplish this? (http://www.adafruit.com/products/1085)

Am I right in thinking that the Pi can read digital signals and control digital device (relays etc) out of the box without additional boards?

The bike it is going on is rather unusual. Its a Honda Superdream with the engine replaced with a 3 cylinder Kubota diesel engine.

As a result, the idea is to get the pi to display:

Speed
RPM
Engine temp
Indicator lights, oil pressure lights etc.
and also control:

Electronic water pump
Electronic cooling fan
Glow plug (both pre glow and post glow)
various other things (external indicator lights)

I also understand that the pi will need a heavily regulated power supply, and will need to shutdown and bootup, which isn't a great issue.

Even though the above isn't trivial, is it something that could ultimately be accomplished?

Thanks all.

henryhanselscott
Posts: 107
Joined: Sun Jan 18, 2015 1:31 pm

Re: Raspberry Pi as Motorbike Dashboard

Tue Jun 16, 2015 4:44 pm

Am I right in thinking that the Pi can read digital signals and control digital device (relays etc) out of the box without additional boards?
The pi is a 3.3 volt device at the inputs and outputs and VERY low current on the outputs. So, really it is not directly able to connect to most sensors and drive most loads. There are add-on boards that make connecting to sensors and driving loads much more feasible. If you are into electronics then you could build your own board that suits the exact needs that you have. This is my approach. Sounds to me like you need support electronics that can.

1. Read digital signals of higher voltages than the pi can take directly, then translate this into pi level voltages for the inputs
2. Read analog inputs and communicate the information to the pi via serial or other known methods (ADC)
3.Take low level output signals from the pi and then drive high current loads through either relays or transistors
4. Have a way for the pi to safety shut down when the bike is turned off with the key
Even though the above isn't trivial, is it something that could ultimately be accomplished?
Yes, absolutely.

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