Interface with in-car lcd display

[Paul Noga]

I'm looking to upgrade my current in car display (which is just a basic
clock), to a multi-line lcd display that comes with higher-spec models. As
far as I understand it, in order to interface with the engine management
unit to provide details of temperature, mileage, faults, the entire engine
wiring loom would need to be replace which is way too much work. So I was
thinking that maybe I could just source a genuine replacement lcd display
part (very cheap off ebay), and somehow drive it to display just the time
plus maybe a few other bits of static info (ie. not requiring any external
data from the car's sensors) to spice things up a bit.

Would anyone have any ideas as to how I could go about doing this? Please
ask away with any additional information that you would require and I'll try
my best to respond. I may possibly be looking to pay someone to design the
driver unit for this as I know of many people in my online vehicle community
for this particular model that would pay good money to have this sort of
aftermarket upgrade to their vehicles.

Please respond on here or reply to my email address omitting the spamtrap.

 

[[email protected]]

Your best bet would be to find a digital gauge set that closly matches
the existing display and go with that rather than try to interface with
the existing one. A google search turned up a lot of vendors. Here's
one that looks interesting. http://www.dakotadigital.com/index.cfm

 

[Paul Noga]

Your best bet would be to find a digital gauge set that closly matches
the existing display and go with that rather than try to interface with
the existing one. A google search turned up a lot of vendors. Here's
one that looks interesting. http://www.dakotadigital.com/index.cfm

Hmm, well this is the kind of display I was originally after:
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=10406&item=4554416828&rd=1

So something similar to this (to stick with the current look of the car
interior), would be best - unfortunately I can't find anything close on that
site!

 

[Luhan Monat]

I'm looking to upgrade my current in car display (which is just a basic
clock), to a multi-line lcd display that comes with higher-spec models. As
far as I understand it, in order to interface with the engine management
unit to provide details of temperature, mileage, faults, the entire engine
wiring loom would need to be replace which is way too much work. So I was
thinking that maybe I could just source a genuine replacement lcd display
part (very cheap off ebay), and somehow drive it to display just the time
plus maybe a few other bits of static info (ie. not requiring any external
data from the car's sensors) to spice things up a bit.

Would anyone have any ideas as to how I could go about doing this? Please
ask away with any additional information that you would require and I'll try
my best to respond. I may possibly be looking to pay someone to design the
driver unit for this as I know of many people in my online vehicle community
for this particular model that would pay good money to have this sort of
aftermarket upgrade to their vehicles.

Please respond on here or reply to my email address omitting the spamtrap.

Hi,

From the tone of your question, it seems you have little experience in
electronics and engineering.

From the complexity of your question, I suggest you 'cant get there
from here'.

I have about 40 years in electronics and would hesitate to try this myself.

 

[Jim Thompson]

Hi,

From the tone of your question, it seems you have little experience in
electronics and engineering.

From the complexity of your question, I suggest you 'cant get there
from here'.

I have about 40 years in electronics and would hesitate to try this myself.

I have 43 years, after BSEE, experience in automotive electronics ;-)

I've yet to run across a vehicle that didn't have a COMPLETE wiring
harness, such that any FACTORY accessory couldn't simply be plugged
in.

Just take a look under your dash sometime and count the unused
connectors tucked in there.

...Jim Thompson

 

[Paul Noga]

I have 43 years, after BSEE, experience in automotive electronics ;-)

I've yet to run across a vehicle that didn't have a COMPLETE wiring
harness, such that any FACTORY accessory couldn't simply be plugged
in.

Just take a look under your dash sometime and count the unused
connectors tucked in there.

I have done, and didn't actually find any prominent wires that looked like
what I was after (that's not to say it's not buried deeper in the dash).

Unfortunately being a French car it does actually lack a complete wiring
harness - as I found when trying to install an aftermarket fog lamp kit
which comes as an optional extra for the car. I was intially told the wiring
would just be dangling loose and that it was a plug and play affair,
unfortunately it required the fitting of the wiring from scratch.

 

[Paul Noga]

From the tone of your question, it seems you have little experience in

electronics and engineering.

I'm not entirely sure what 'tone' you're inferring, but I'm currently in my
second year at degree level doing an electronic and electrical engineering
degree

Though as I'm currently on vacation I can't really get in touch with my
tutors to ask them this question.

From the complexity of your question, I suggest you 'cant get there from
here'.

Meaning?


I have about 40 years in electronics and would hesitate to try this
myself.

From what I understand, albeit on a basic level as we haven't covered this
sort of stuff in any of my degree modules, a dot matrix display requires a
microprocessor to drive it and perhaps an eeprom to store the information
required for display. What exactly am I missing here that would impede
giving this a try?

 

[Jim Thompson]

I have done, and didn't actually find any prominent wires that looked like
what I was after (that's not to say it's not buried deeper in the dash).

Unfortunately being a French car it does actually lack a complete wiring
harness - as I found when trying to install an aftermarket fog lamp kit
which comes as an optional extra for the car. I was intially told the wiring
would just be dangling loose and that it was a plug and play affair,
unfortunately it required the fitting of the wiring from scratch.

Have you surfed for a factory-level manual with wiring diagram? MANY
years ago, as in 1963, I managed to get a complete manual on my 1961
Renault Dauphine, from a bookseller in London.

I then proceeded to install a Ford 60A alternator in place of the
generator ;-) (I was designing alternator regulators back in those
days.)

...Jim Thompson

 

[Paul Noga]

Have you surfed for a factory-level manual with wiring diagram? MANY
years ago, as in 1963, I managed to get a complete manual on my 1961
Renault Dauphine, from a bookseller in London.

Jim, from what I understand it's not only a question of missing wiring
(going from what a few people in the Peugeot community have told me), but
also the fact that the engine ECU lacks the features to provide the info to
pass on to such a display. Would I be correct in saying that ECU's differ
from engine to engine, that not all features are supported (and some
disabled), and I would require a completely new engine if I wanted to
upgrade the ECU?

 

[Jim Thompson]

Jim, from what I understand it's not only a question of missing wiring
(going from what a few people in the Peugeot community have told me), but
also the fact that the engine ECU lacks the features to provide the info to
pass on to such a display. Would I be correct in saying that ECU's differ
from engine to engine, that not all features are supported (and some
disabled), and I would require a completely new engine if I wanted to
upgrade the ECU?

That could well be. On this side of the pond I think the ECU, for a
given engine, has all the features. Since service is done by simply
plugging into a connector to read out all the data.

I've not seen a recent vintage Peugeot around here (Arizona)... do
they still sell them in the States? (But I've seen some "golden
oldies", like the one Columbo drives on his TV show, a dilapidated
1959 Peugeot 403 Grande Luxe Cabriolet.)

But, going back to the display, if you can sort out how to talk to it,
I'm sure you could create your own sensors and interfaces (with some
help from tutors... heaven help you if they're typical academics

...Jim Thompson

 

[[email protected]]

You're going to need to be creative. Search around - google, car
newsgroups and eb sites, even print catalogs. Find the best fit, or
the closest thing you can find and MAKE it work. I've done a lot of
work on hot rods and custom cars. Once you go beyond what the factory
offers, you're generally on your own. If you're just starting out,
this can be frustrating, and you *will* make mistakes! Two inportant
things to remember are: limit the damage mistakes make, and learn from
the ones you do make.

 

[Ian Stirling]

Jim, from what I understand it's not only a question of missing wiring
(going from what a few people in the Peugeot community have told me), but
also the fact that the engine ECU lacks the features to provide the info to
pass on to such a display. Would I be correct in saying that ECU's differ
from engine to engine, that not all features are supported (and some
disabled), and I would require a completely new engine if I wanted to
upgrade the ECU?

Of course not.
http://www.megasquirt.info/
Problem solved.