Posts

System Design

Image
After some reasonably careful thought, I have come up with a tentative design for the system... The recessed area of the dashboard where the current instrument cluster sits is just about the size of two large phones.  It seems to me that economies of scale have made phones reasonably inexpensive, as well as being reasonably robust and very compact.  So the plan is to pick up a couple phones to use for the display of the digital dash. The signals from the car are both analog and digital.  They add up fast!  It seems to me that 16 digital lines (by "digital" I just mean ON or OFF) and 8 analog lines should be enough to receive all the data of immediate interest.  The phones have no way of acquiring all those data lines, so I'll need some interface electronics.  My plan is to get an inexpensive "discovery" board for a microcontroller (which is designed simply for people to play around with and experiment), and then add some custom electronics to it. Here is a
Post a Comment
Read more
Image
Here's what the current "instrument cluster" looks like on the dash of the car, seen roughly from where my eyes are when driving: The most natural thing is definitely to take over the recessed section, filling it with a new set of display elements.  The size of the area is slightly awkward though... approximately 300mm wide and 85mm tall.  That would ALMOST be perfect for one common automotive display form factor, a wide 12.3" diagonal display.  Unfortunately, the only ones I have been able to find in a usable form are around $300 which is more than I want to spend. Using two displays side-by-side is a good option also, and I'm leaning toward that.  In particular, there are other things to consider that make such an option attractive: I am going to need to hook up a large number of digital and analog "sensor" channels to the systems of the car, which means a bunch of custom interface electronics and a microcontroller to read the values.  Perh
Post a Comment
Read more

Goals

At a bare minimum, I need to keep track of, and display, the same information that appears on the current "instrument cluster" of the car.  This list isn't too huge: The speedometer is the major one of course. Also there are two "analog" gauges:  Fuel Tank level Coolant temperature Besides those, there are a large number of "indicators" which may or may not be "active"...  After a bunch of research in the electrical manual, those indicators are: Check Engine Air Suspension Warning Washer Fluid Low Warning Door Ajar Warning Oil Pressure Warning Seat Belt Warning Air Bag Warning Anti-Lock Brake Indicator Brake Warning Charge Status Warning High Beam Indicator Left and Right turn signal indicators And additionally there is the odometer-related data: Total Odometer Trip Odometer Getting all that would replicate the functionality of the current dashboard display.  BUT... it would be nice to have some more information
Post a Comment
Read more

Digital Dashboard for my 1992 Lincoln Town Car!

Recently the twists and turns of life left me in a fairly rural part of the US with very little money and no car.  I needed a car so I ended up buying a really cheap 1992 Lincoln Town Car.  To my surprise, I found that I actually liked this car quite a bit and decided to slowly work at fixing the many problems that come with such an ancient somewhat neglected automobile... most of that stuff isn't really of much interest to The World, but there is one thing... Turned out that the odometer doesn't work on the car.  I got lucky and managed to find the Service Manual and Electrical Manual for this exact model of car on eBay almost for free so I grabbed them and they have been helpful in understanding this beast as I try to figure out various problems. The troubleshooting procedure for the odometer informed me that the whole assembly needs to be replaced.  It isn't so easy to find those and about the best I can do right now is around $100 on eBay for one torn out of a junke
Post a Comment
Read more