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PostPosted: June 13, 2014, 12:29 pm 
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Location: Richmond, VA
So the gauge cluster in my Corolla no longer agrees with the engine I put in it. The tach only goes to 8k and is incompatible with COP ignition, and the speedo is cable driven. I decided I wanted a new cluster.

My first intention was to use an S2000 cluster. Picked one up on ebay, bought connectors and pins, and started looking at what would be involved in mounting it and driving it. There's a company called JSP Fab who makes a mounting bezel, but it puts I'm not happy with it. Driving it would involve something like an Arduino to convert inputs into something the cluster can talk to. After some soul searching I decided to build my own dash with the arduino and some displays.

A few days later, here's a functioning prototype:
Image

The wirey thing on the left is an arduino uno with two shields on top of it. You can kinda see that it's a stack of three PCBs. The middle shield is a CAN Bus shield from Seeedstudio and on top of it is a MakerShield from MakerShed with a breadboard adhesived to it. On top of the breadboard is an [urlhttp://www.adafruit.com/products/746]Adafruit Ultimate GPS brekout board[/url]. It is what I'm using to read my speed. The display is a RGB backlight positive 20x4 character display.
Right now the assembly is being driven by my Megasquirt 3 hooked up to a JimStim.
The Arduino talks to the Megasquirt via CAN Bus, which means there are only two wires connecting the arduino to the Megasquirt. Any data the Megasquirt sees or generates can be sent over CAN Bus and read by the Arduino. Right now it is reading RPM, lambda (air to fuel ratio), and water temperature.
The GPS sends the Arduino position and speed information over a two wire serial connection. It takes it a bit to get a fix, so I'll probably be putting in a battery backup for the GPS unit and also getting a digital speed sensor for the transmission.
Fuel level comes from the regular fuel sender. If I ever have to open up the fuel tank I'll try to install a strip level sensor.

The screen is about 3 in long and 1 in tall. Right now the bar at the top is RPM, with 0 on the left and redline on the far right. Below that on the left is a numerical RPM read out. On the right is speed. There's nothing there until it starts moving, so it's blank right now. Below that is lambda, next to it is a bar read out for oil pressure and then fuel level. At the bottom is water temperature.

I'm thinking about having a larger screen for the tach and speedo only. It would be a 40x4, so it would be the same screen, only twice as long. The current screen would then be only for ancillary information. I'm also thinking of switching to a full LCD.

To temporarily mount the screen I grabbed a piece of masonite, pulled the bezel off the original gauge cluster, and used some double-sided tape.
Image
Image

I need to put some warning and indicator lights. I would like lights which have the proper symbols. I saw a bunch which would work well from UK vendors like these. I'm curious if anyone has found anything here in the US which would work.

The next step for me will be smooshing all of that Arduino into a case so I can continue prototyping on the car without risking losing a connection. Here's an enclosure with an Arduino Micro and the GPS breakout in it. I have to find room for the CAN Bus chips and the ancillary circuits, but it looks like it will all fit.
Image
This would be a fully functioning unit, but I'm not going to stop there :mrgreen:


Last edited by killer_siller on June 17, 2014, 8:14 pm, edited 1 time in total.

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PostPosted: June 13, 2014, 12:35 pm 
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Nice work.

I've been tempted to play with the arduino but never got the final urge to pull the trigger. It looks like it has a lot of support.

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PostPosted: June 13, 2014, 1:06 pm 
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Location: Richmond, VA
rx7locost wrote:
Nice work.

I've been tempted to play with the arduino but never got the final urge to pull the trigger. It looks like it has a lot of support.


I picked up the Arduino Micro, character display, and GPS board a while ago and did nothing with them. Finally last week I decided to do something with it. I picked up the Uno, breadboard, jumper wires, CAN Bus shield and MakerShield. Three days later I had the prototype working the way I wanted. I was very happy with how easy everything went together, how well documented it is, and how painless the process is. I had no previous experience with C programming, or any C derivative language, but had done quite a lot of programming in Python, so that wan't all that difficult for me.

This week has been learning how to draw up PCBs for etching.


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PostPosted: June 13, 2014, 1:50 pm 
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Joined: October 19, 2012, 9:25 pm
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Location: Summerville, SC
how much do you have in parts?

Could you send data to a small tablet or e-reader?

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http://www.locostusa.com/forums/viewtopic.php?f=35&t=17496

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PostPosted: June 13, 2014, 2:03 pm 
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Location: Richmond, VA
TooBusy wrote:
how much do you have in parts?

Could you send data to a small tablet or e-reader?


I'd say less than $100 for the prototype boards, which I'll be able to use for other projects, and probably $100 all together for the finished version.

Could probably output to something like a tablet. Eink display refresh rates aren't fast enough for things like RPM, but could work for fuel level or coolant temp.

There'll be another $50 or so in nice LED warning/indicator lights unless I decide to do something stupid like make my own. I might just use standard LEDs and write what they do on the backing plate, that'd be the cheap way to do it, but it's really nice having the symbol on them.


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PostPosted: June 13, 2014, 2:48 pm 
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My son built a 25 RGB LED ambient backlight for his computer monitor with the Ardiuno. makes watching movies and playing video games a lot more realistic

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OOPS I did it again
http://www.locostusa.com/forums/viewtopic.php?f=35&t=17496

Blood Sweat and Beers
http://www.locostusa.com/forums/viewtopic.php?f=35&t=15216


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PostPosted: June 13, 2014, 8:27 pm 
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TooBusy wrote:
My son built a 25 RGB LED ambient backlight for his computer monitor with the Ardiuno. makes watching movies and playing video games a lot more realistic


Does he help you with your locost?


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PostPosted: June 14, 2014, 8:25 pm 
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Location: northampton ma
Hi. I got a $80 tablet,ms shadowdash,,GPS,, hook them together and you have 4 screens of custom gauges..plus records your drive for later tuning.
Works well except in direct sun glare.
Read up at tunerstudio.com


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PostPosted: June 14, 2014, 9:34 pm 
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rad wrote:
Hi. I got a $80 tablet,ms shadowdash,,GPS,, hook them together and you have 4 screens of custom gauges..plus records your drive for later tuning.
Works well except in direct sun glare.
Read up at tunerstudio.com


Nifty. I'm familiar with the software. This was an inexpensive project to get my feet wet in arduino stuffs and work toward something cool. I have a fum eventual goal for this that I think will be really cool.

I may, down the road, grab a nice screen to throw in it and pair it to a beaglebone or raspberry pi. It'd be easy to get android involved to run the shadowdash and be fully integrated.


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PostPosted: June 15, 2014, 8:22 am 
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killer_siller wrote:
TooBusy wrote:
My son built a 25 RGB LED ambient backlight for his computer monitor with the Ardiuno. makes watching movies and playing video games a lot more realistic


Does he help you with your locost?


Not often enough. We did build him a full custom computer case a couple of months ago to demo how Locost fabrication skills translate to his primary hobby.

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Too much week, not enough weekend.

OOPS I did it again
http://www.locostusa.com/forums/viewtopic.php?f=35&t=17496

Blood Sweat and Beers
http://www.locostusa.com/forums/viewtopic.php?f=35&t=15216


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PostPosted: June 17, 2014, 9:14 pm 
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DIP sockets and CAN Bus chips came in. Looks like I'll be able to fit everything in that enclosure and use DB9 or DB15 connectors between the enclosure and the chassis harness and the enclosure and the display.

Image

So I went back and started putting my circuit together with the components I'm going to use on a breadboard.
Image


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PostPosted: June 26, 2014, 8:13 am 
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I was having trouble getting CAN Bus to work off the shield, so I went back and put the circuit together on the breadboard shield:
Image

That worked. So I copied the circuit over to the Arduino Micro:
Image

That also worked! Now I'm assembling the rest of the circuit on that breadboard before moving it to the enclosure.


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PostPosted: June 27, 2014, 4:16 pm 
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This is really awesome stuff you're doing!

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PostPosted: June 27, 2014, 11:22 pm 
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Laminar wrote:
This is really awesome stuff you're doing!


Thank you!

So it turns out laying out circuits on a perfboard is something I suck at. Even if it's paired pads. I ended up taking a Radioshack Coupon I had and picking up a cheap perfboard which is laid out similar to a breadboard and building my circuit on there. It works, but it isn't pretty, and I don't have an enclosure for it. I'll just attach it to the back of the bezel with some stand offs or something like that.
Image

Either way, there's version 1. Next is adding warning/indicator lights. I still don't have a good solution there. I'll also be rebuilding this circuit on some stripboard in a nice enclosure. I think I'll make some breakout boards for the CAN Bus interface, as it looks like I'll be building a bunch of these. That's something I can have made up on a few PCBs, maybe even sell a few over on the Megasquirt forum.


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