ultra cheap gauge to display any ECU parameter

[acannell]

I connected some ingredients I had around to setup a proof-of-concept.

Its a small microcontroller, which talks to the ECU (T1 SBEC in this case) over the diagnostic connector, reads a parameter (in this case TPS volts), and then displays that parameter on a small LED 7 segment display.

The video shows the whole mess, along with the scope trace showing the output of the SBEC changing as I slowly change the TPS voltage from 0V to 5V. The display on the gauge also changes to show the value go from 0 to 255.

I dont want to get into the electronics that I used to do it. Its a mess and was just what I had laying around. Theres nothing special about it. But I wanted to make sure I could actually read a parameter from the ECU and display it on custom hardware and firmware. Always nice to get that foundation solid.

SO. The product idea is this:

-display 1 or more ECU parameters in real time
-have a serial and/or bluetooth output to allow those parameters to be logged on laptop/phone if desired
-always-on functionality like any other gauge, no fussing around with cables, laptops that have issues, problems getting things working. You install it just like another 2" gauge and you can always see the parameter(s) you want to see.
-CHEAP AND EASY. Cut every corner to make it cheap.

So for instance if you want a gauge that always shows you knock sensor counts or knock retard this could show you that. Not just when you have a laptop and MPTUNE running, but ALWAYS. Just like your boost gauge.

How many parameters it can show depends solely on the display. So I would find the absolute cheapest display that would allow as many parameters as possible to be shown.

So would anyone be interested in something like this? How many parameters would you want to observe on a gauge like this? Would you want to use the logging or would you just use MPSCAN for that during more dedicated "tuning" runs?

By "parameter" I mean anything the ECU will output over the diagnostic connector which is pretty much everything imaginable from injector pulse width to rpm.

And of course all parameters would be appropriately scaled so they are easily understandable. In the video it shows TPS volts as 0-255 because thats what the ECU spits out, but in the product it would be 0-5V or whatever the actual parameter is.

And by cheap, you know I mean it. You can already get MPSCAN up and running for very little money so this is not meant to compete with that, its mean to be an always-there, always-on, way to observe critical engine parameters.

VIDEO CLICK HERE: https://vid.me/3GGS

[shackwrrr]

I'm game for kit form or pcb only, need to dust off the soldering station. Something based off those cheap 4 line lcds would be nice.

[cordes]

I am very interested in this.

[acannell]

GROUP BUY
1. shackwrrr
2. cordes

lol! J/k

well not really..

this is so easy theres not really much between now and a working product

but I need to know EXACTLY how you guys want it..what kind of display do you hate/like, how many parameters do you want to see, just how cheap can I go, i.e. would a potted rectangular display with 6 wires coming out and two holes for screws work for you or do you need a circular gauge that actually fits in a standard hole, etc..etc..

Im thinking to serve the TM humanity best I should cut EVERY corner and make something that makes it so every person no matter how broke can observe knock counts live and/or knock retard

Not that this is limited to that. Technically any parameter could be observed. And any actuator test or switch test could also be monitored or activated.

Code is free and most hardware like switches, wires, serial ports is cheap. So with a clever design you can pack a tremendous amount of functionality into a small, cheap device.

For instance, if you look at an OTC 2000 scanner, its got a 1 line display and you can basically read every parameter and test every actuator and switch, and read and erase faults, with the use or 2 or 3 buttons. You dont need much to create a very powerful tool.

Hmm maybe I should make this an OTC 2000 scanner clone but since it will use 21st century technology it would be the size of pack of gum, and have a special feature that allows continuous display of any parameter and automatic startup and configuration, so it acts as a gauge. That would make it a tool for not only people who are at the "observing knock retard' stage, but also everyone else who is at the "cant start the engine" phase of troubleshooting.

????

[shackwrrr]

http://www.turbo-mopar.com/forums/sh...ad.php?t=76333
DRB II LCD Modification

This display due to the price and expandability. I would think 8 parameters with lables or 12 without labels. a standalone would be nice but it would be cool to have the display remote mountable so you can "hack" it into the cluster or a traveller housing.

[shackwrrr]

a standard project case would work, if the end user wanted to mount it to a 52mm gauge pod, a 52mm "spud" cpuld be affixed to the back for mounting.

[acannell]

http://www.turbo-mopar.com/forums/sh...ad.php?t=76333
DRB II LCD Modification

This display due to the price and expandability. I would think 8 parameters with lables or 12 without labels. a standalone would be nice but it would be cool to have the display remote mountable so you can "hack" it into the cluster or a traveller housing.

That VFD is awesome looking but its $84 in single quantity. In the spirit of making this as cheap as possible I think the display component needs to definitely be less than $10 for a multi parameter display. And for a single parameter display less than $3.

4 digit 7 segment LED displays like the one in the video are about $1.50 each. That would do fine for a single parameter display but would make any sort of user interface a somewhat tricky affair with very limited display of letters. But it could be done. In a pinch, when you need to just test an actuator or read some parameter, I think having to press a button some arcane number of times and read funny look abbreviations would be worth it.

But if we want some luxury with actual labeled values then I think it could still be done for less than $10. At say 25 quantity probably less than $5. There are alot of alphanumeric LCD's out there and they cheappppppp

So lets say alphanumeric, can display say....at least 10 digits per line and has 4 lines for 4 parameters each with a label.

Now, its not fun trying to read a tiny 5mm square character while you are driving. It may make more sense, if the display is to be capable of multiple parameters, that it be graphical, so that if need be the font can be increased in size dramatically for single-parameter display.

[acannell]

I've used this EADOGS series before on another project. Its only $13 at 50 qty and is graphical with a 102 x 64 resolution. For a 7 x 7 font thats roughly 10 char and 9 lines if you really pack it in. Or you could do a much bigger font.

Theoretically since its graphical you could draw an analog gauge on it too instead of numeric value.

http://www.mouser.com/ProductDetail/...%2fB4LZQ%3d%3d

[shackwrrr]

http://www.buydisplay.com/default/di...qOEaAp5K8P8HAQ

Here is a 20x4 with a good price. The white on blue displays really pop and I think they would work well. I'm a tinkerer so something cheap could come with it and later on I could throw in a VFD.

[acannell]

http://www.buydisplay.com/default/di...qOEaAp5K8P8HAQ

Here is a 20x4 with a good price. The white on blue displays really pop and I think they would work well. I'm a tinkerer so something cheap could come with it and later on I could throw in a VFD.

Wow that is cheap!

Okay so as far as multiline alphanumeric looks like price is not an issue.

But personaly I would not want to try and read small letters like that as a true-gauge-like-function. I think it makes it more of a diagnostic tool to look at on a dyno or for other troubleshooting than something you want to use as a gauge. So something graphical would be preferable IMO.

And something with a more square shape so if need be it can more reasonably fit into a standard gauge pod hole to make it more compatible with more typical mountings.

[shackwrrr]

if you peek around that site there are some cool b/w oled screens that would work great in a 52mm housing. I personally don't like round housings, too much wasted space. The few 52mm gauges I have I don't like.

[OmniLuvr]

im trying to follow all the awesome lcd talk, but im a little slow today

id like to have a bunch of large # lcd displays, something like an alarm clock, that i could label myself, im thinking something that would belong in the delorean of the "back to the future" or "kit" from night rider, just large #'s that display voltage, ms, or whatever you need. no covers, housings, or filters, just bare lcd and exposed wires, and you could add individual "gauges" as needed, then make your own housing and filters if wanted. i just want something that would be very easy to glance at and read while the torq steer is trying to rip the steering wheel from your hand.

And could this be modular? like add or subtract lcd's as needed? leaving just a knock gauge in there, or have coolant, 02, knock, tps, fuel trim, voltage etc being displayed at one time?

or does this need to be an lcd with multiple displays and labels like the scanners do? im pretty electronically newbie status, good with electrical tho...

[acannell]

im trying to follow all the awesome lcd talk, but im a little slow today

id like to have a bunch of large # lcd displays, something like an alarm clock, that i could label myself, im thinking something that would belong in the delorean of the "back to the future" or "kit" from night rider, just large #'s that display voltage, ms, or whatever you need. no covers, housings, or filters, just bare lcd and exposed wires, and you could add individual "gauges" as needed, then make your own housing and filters if wanted. i just want something that would be very easy to glance at and read while the torq steer is trying to rip the steering wheel from your hand.

And could this be modular? like add or subtract lcd's as needed? leaving just a knock gauge in there, or have coolant, 02, knock, tps, fuel trim, voltage etc being displayed at one time?

or does this need to be an lcd with multiple displays and labels like the scanners do? im pretty electronically newbie status, good with electrical tho...

Anything can be done as far as modularity. But the idea is to realistically come up with a design that will make sense for most people and have the most powerful functionality.

Im thinking a device which has OTC2000 diagnostic functions (display any sensor, actuate anything, read/clear faults), and also can be set to a "gauge" mode where it shows one parameter all the time automatically, would really be useful to the most people for more than one reason (diagnostics plus in-car knock monitoring) and also be the simplest and cheapest.

Big digits like LED 7 segment displays are the easiest to read, thats why they are still used to this day on modern gauges. Small text is better for handheld diagnostic tools used for tuning while you arent driving. I think the best of both worlds might be had with a graphical display that can show small text and big text when desired, the cost would be about 4 to 5 times as much as a simpler 4 digit LED display but we're talking $2 versus $10. Not $10 versus $50. It still might work out for a low cost device.


OTOH my dual thermocouple gauge has all the hardware, which is what the video shows disassembled being used for the proof-of-concept, has two 4 digit 7 segment displays and all the electronics and housing already designed. I could turn it into this new device pretty easily. But it would just be two 4 digit lines, 7 segment. I can display some letters but not all. But I bet I could make a user interface that would do the job. If I go that way I could get things rolling pretty fast since so much of it is already designed. There would probably be some minor hardware changes and a connector for the chrysler diagnostic socket would need to be designed so its 90% there I'd say.

[cordes]

http://www.turbo-mopar.com/forums/sh...ad.php?t=76333
DRB II LCD Modification

This display due to the price and expandability. I would think 8 parameters with lables or 12 without labels. a standalone would be nice but it would be cool to have the display remote mountable so you can "hack" it into the cluster or a traveller housing.

I would love a display like that. This is what I really had in mind. I figure I could put an LCD in a case and do my own thing there. Is this thing going to run off of an Arduino?

[acannell]

I would love a display like that. This is what I really had in mind. I figure I could put an LCD in a case and do my own thing there. Is this thing going to run off of an Arduino?

Anyone knowledgeable enough to wire up an LCD is only a few inches away from writing the simple code it takes to talk to the chrysler ECU's. Its REALLY easy. If you are thinking of an electronics project this has all the ingredients of a great experience. Cosmetics, powerful tool for your car, easy coding, and the rich possibilities for all kinds of insane functionality based on what you can control and read from the ECU.

If I use the existing hardware in my dual thermcouple gauge the processor would be a PIC. I'd most likely use a PIC even if I dont use the same hardware because I already have a large code base written up for them. But you could do chrysler ECU communications even in BASIC on anything. Are you thinking of making something from scratch?

[OmniLuvr]

Anything can be done as far as modularity. But the idea is to realistically come up with a design that will make sense for most people and have the most powerful functionality.

Im thinking a device which has OTC2000 diagnostic functions (display any sensor, actuate anything, read/clear faults), and also can be set to a "gauge" mode where it shows one parameter all the time automatically, would really be useful to the most people for more than one reason (diagnostics plus in-car knock monitoring) and also be the simplest and cheapest.

gotcha!

im using a scanner now that can display 5 pids at one time, but sometimes its not enough and the display is pretty small (but does have a back light), i wish i knew more, id dissect my scanner (its a auto x-ray orielys unit) and replace the display with a larger screen with bigger letter/#'s, and make it a semi permanent unit.

im still interested to see how this turns out...

[cordes]

Anyone knowledgeable enough to wire up an LCD is only a few inches away from writing the simple code it takes to talk to the chrysler ECU's. Its REALLY easy. If you are thinking of an electronics project this has all the ingredients of a great experience. Cosmetics, powerful tool for your car, easy coding, and the rich possibilities for all kinds of insane functionality based on what you can control and read from the ECU.

If I use the existing hardware in my dual thermcouple gauge the processor would be a PIC. I'd most likely use a PIC even if I dont use the same hardware because I already have a large code base written up for them. But you could do chrysler ECU communications even in BASIC on anything. Are you thinking of making something from scratch?

I've already made a device that will output temp and boost pressure to an LCD. It would be nice if I could get it to display the computer stuff too.

[knownenemy]

I like the idea of having a gauge that would read any parameter I choose.

How about wiring to several different readable parameters,
and a simple 5,6 or 8! position switch that can be switched from one to another to the same gauge?
(ie: Switch position #1 is knock, Switch position #2 is 02 sensor voltage, etc, etc, etc...)

wuddya tink?

[ShelGame]

I like the idea of having a gauge that would read any parameter I choose.

How about wiring to several different readable parameters,
and a simple 5,6 or 8! position switch that can be switched from one to another to the same gauge?
(ie: Switch position #1 is knock, Switch position #2 is 02 sensor voltage, etc, etc, etc...)

wuddya tink?

This.

Asa, there's another DRBII command that will output 1 of 16 different PIDs. The scantools expect certain PIDs in each slot, but there's no reason they can't be changed for this device. An up/down toggle could then be used to 'scroll' the PIDs.

The usual PIDs are rpm, speed, o2 volts, knock on each cyl, injector PW, etc. The main stuff.

MP Scan uses the development command that gives it access to all 256 RAM locations. Not sure what command you used.

Myself, I still want a stand alone automatic data logger that will log selected channels to a .csv file on a microSD card for later analysis in Excel.

[wowzer]

Rob,I'm looking at an arduino to do this for me also. Actually was going to start on it in a few months. Mpscan uses two methods to get data as rob said, the high speed 0x12 method for scanning and the diagnostics method that the OTC type scanner uses to get the selected pids as well as run some of the actuator tests. Really interested in what you're doing also asa. Be great to come up with a cheap way to bypass the ftdi cable setup and still get the data out of the ecu reliably and easily. Curious how you're dealing with the inverted TTL signals and what baud rate you're using.