Replacing the dash cluster with a lcd screen

[bakes]

Looking for anyone or info on replacing the old mechanical cluster with a lcd screen . Why you ask ? 1. Well it's hard to finding good working gauges nowadays . 2. i can set up any gauge i want or use it with Mp tuner or scanner. 3 i can pick my own skins and backdrop ( just that alone is cool sh*t )
I know i will be running small pc with bluetooth for key board and usb ports . I think touch screen is cool but will add a lot more work .

[shackwrrr]

Subbed, been researching this for use in my truck and van. I don't like having lots of gauges all over the place. I'd rather have a small LCD gauge that I can scroll through to see the critical items. I'm interested in using an android based unit but I can't find any worth using. I would like a unit that has 5 or so 0-5v inputs, and an EGT input. I have no EE experience but it seems that this could be a very simple device with Bluetooth connectivity.

[acannell]

Subbed, been researching this for use in my truck and van. I don't like having lots of gauges all over the place. I'd rather have a small LCD gauge that I can scroll through to see the critical items. I'm interested in using an android based unit but I can't find any worth using. I would like a unit that has 5 or so 0-5v inputs, and an EGT input. I have no EE experience but it seems that this could be a very simple device with Bluetooth connectivity.

I seriously considered developing a glass c0ckpit module that would replace one of the three instrument cluster modules in my 90 daytona. You're right, it would be a relatively simple device and for anyone who wants a very rewarding electronics project it would be a ton of fun. I think its actually not overkill, and justified, if you want to have alot more sensors like thermocouples and pressure, have them all logged and displayed, and also output to MPSCAN.

I already have the sampling and analog front ends done via the electronics in my dual thermocouple gauge. And I've gotten those electronics to talk to my android phone via bluetooth, as well as to the chrysler ECU, including intercepting and manipulating the chrysler data stream, which would allow you to send your 0-5V inputs to MPSCAN for combined logging. So all the pieces have been proof-of-concept-ed for an insane sampling/logging/displaying glass c0ckpit drop in super gauge. So its a matter of putting it all together into a drop-in unit.

There should be off-the-shelf LCD's that would fit the bill for a from-scratch design. I'd check digikey and mouser since their search engines are pretty good. Narrow it down by dimensions, then technology, then price. Want to make sure it is readable in the real world lighting conditions in the cab.

If anyone wants to take this on as a project I'd be happy to help with advice. Combining interests like electronics and automotive can be VERY fun....I know a few people on here are into both and I would really suggest going for it, it will pay huge dividends. Be warned though I am not a fan of integrating hobbyist components into new designs aka arduinos and what not. So if thats the way you want to go you're own your own

But, another reasonable way to approach this would be to simply get a cheap small LCD monitor that hooks up to your laptop/netbook running mpscan. Wont have all the extra inputs but might be a good enough solution for some.

[shackwrrr]

I can solder pretty good and know my way around some hardware, ill offer any help I can if someone goes forward with something.

[shackwrrr]

https://www.chariotgauge.com

I was looking at this unit and I like the price and setup but I talked with the developer and there wasn't any interest in opening up the possibility of configuing the inputs for other uses. On my diesel I have no need for a WBO2 input so wanted to use the input for something else.

Using the existing mpscan software is a great idea as the system to setup gauge parameters is already there.

what ICs are available that offer a decent selection of inputs? Also low level outputs if those are cheap enough. You could set up arming outputs for boost pressure or temp.

[EaZyE426]

I've been thinking about looking into a Raspberry Pi 2 running the new Windows 10 for it. Not sure if it'll run mpscan though.

[RoadWarrior222]

Theoretically, you can just pick up a cheap android tablet, open it up, find the JTAG pads or connector, find the serial lines, break them out, enable serial on the tablet (probably requires root), wire that serial to the serial on the SBEC/SMEC diagnostic connector, I believe it should already be 5V levels. Then dig up posts here and "there" to help you figure out the serial data, use some scripting for glue, knock up front end in an app creator and robert is your grandfathers other son.

[RoadWarrior222]

BTW those headrest DVD screens come dirt cheap these days if you've only got room for 7" or so and don't want touch. Laptop guts hid somewhere with composite out will light 'em up.

If you don't wanna trust ze mopar micro, you can piggyback arduinos on the inputs, use their analog inputs to read sensors directly, but you practically double up your underhood wiring doing that.

Me... I'm all OBD II + now so just need the bluetooth dongle and I'm set.

[acannell]

Microcontroller:
-Several serial ports (LCD, ECU, ADC's, bluetooth..likely all need their own ports and wont share buses because of different logic levels/bus timing)
-Several ADC inputs with 10 bit resolution (for low precision stuff like TPS, MAP, etc..)
-Cheap development tools
-There are zillions of MCU's which would fit the bill..wont be a problem

For thermocouples you should use something like the TI ADS11xx series which has an onboard cold junction reference and is well characterized for temperature measurement.

If you want a device which has a bunch of new inputs and allows MPSCAN to read those inputs, you will need to send the chrysler SCI bus through your device, and break its connection as needed to insert your response (and silence the ECU's response) when MPSCAN calls your "special" ram locations that will be used to communicate your new inputs values. I've already actually done this so I know it works. It will require a bit of hardware to act as a mux or digital switch and some level shifting.

For bluetooth, an HC-06/05 module can work. They act as serial pass-thrus and are very easy to work with and cheap too.

[csxtra]

Asa,

What is required to get a Microcontroller to talk to the SCI bus? I've got a logging project I'm working on and I haven't yet been successful getting the MCU (actually a Netduino) to talk to the SCI without using an ancient SCI to RS-232 converter then a RS-232 to TTL converter.

It works fine with the RS-232 in the middle, but I'd like to figure out how to eliminate the extra hardware and use a more direct connection between the Netduino and my Logic Module.

Thanks in advance for any help you can give.

[RoadWarrior222]

I've got the feeling that you can hack this to work with a USB port signal level to diag connector, just wiring and driver hax, no point converting to RS232 levels and back again... http://janaxelson.com/usb_virtual_com_port.htm

But get feeling it would not play nice with anything else on same USB root, no fifo.

[acannell]

Asa,

What is required to get a Microcontroller to talk to the SCI bus? I've got a logging project I'm working on and I haven't yet been successful getting the MCU (actually a Netduino) to talk to the SCI without using an ancient SCI to RS-232 converter then a RS-232 to TTL converter.

It works fine with the RS-232 in the middle, but I'd like to figure out how to eliminate the extra hardware and use a more direct connection between the Netduino and my Logic Module.

Thanks in advance for any help you can give.

Here is a document I wrote about the SCI bus which should answer your questions. I wrote it a few months ago and it looks like maybe some parts of it were deleted...not sure, but the important stuff is still there.

http://www.boostbutton.com/turbonato...=sci_tech_info

In short, the SCI bus is 0/5V. So if your processor serial port is 0/5V, and can be configured to operate with inverted logic (5V = logic 0, 0V = logic 1) then you should be able to directly connect the SCI bus to your processor.

If it doesn't answer your questions just keep asking more! I tried to make it a one stop shop type document so that anyone who was trying to connect to the SCI bus would know everything necessary in one small space.

[RoadWarrior222]

just need a NOT gate

TTL level of course, 74 series part. can't get a NOT get a NAND tie inputs.

[csxtra]

Thanks for the link, after reading it, I have a few follow-on questions.

I'm assuming that the ECU is looking for an inverted input signal also, so both the xmit and rcv signals need to be inverted?

For inverting the signal, I had tried using a Motorola 74LS04N inverter chip, with one of the inverters (NOT gates) used for the xmit, and another used for the rcv. Is this a valid configuration?

Since the Netduino's ttl UARTs are 3.3V instead of 5V (they are 5V tolerant for inbound signals, but outgoing signals are 3.3v), I tried using a Sparkfun logic level converter (BOB-12009) to step down the Netduino RCV signal voltage from 5V to 3.3V, and step up the Netduino XMIT voltage from 3.3V to 5V.

Here are the signal paths I tried:

Logic Module Out:
LM XMIT -> 7404 inverter -> 5V to 3.3V -> Netduino RCV

I also tried (since the Netduino RCV is 5V tolerant):
LM XMIT -> 7404 inverter -> Netduino RCV

Logic Module In:
Netduino XMIT -> 3.3V to 5V -> 7404 inverter -> LM RCV

Can you think of anything I missed, or is there any issue with either the 74LS04 or the logic level converter?


I apologize for the thread hijack, but I figure this may be useful to others going down a similar path...

[shackwrrr]

https://code.google.com/p/multidisplay/

found this and it looks promising but requires making your own boards.
https://oceancontrols.com.au/KTA-259.html

This one would give 8 thermocouple inputs right out of the box, then the 5 analog inputs of the arduino would give a good array of input possibilities. On my truck I want to keep an eye on temps from ambient to trans temp.

[acannell]

Thanks for the link, after reading it, I have a few follow-on questions.

I'm assuming that the ECU is looking for an inverted input signal also, so both the xmit and rcv signals need to be inverted?

Yes both sides of the bus need inversion.

For inverting the signal, I had tried using a Motorola 74LS04N inverter chip, with one of the inverters (NOT gates) used for the xmit, and another used for the rcv. Is this a valid configuration?

Sounds reasonable.

Since the Netduino's ttl UARTs are 3.3V instead of 5V (they are 5V tolerant for inbound signals, but outgoing signals are 3.3v), I tried using a Sparkfun logic level converter (BOB-12009) to step down the Netduino RCV signal voltage from 5V to 3.3V, and step up the Netduino XMIT voltage from 3.3V to 5V.

Here are the signal paths I tried:

Logic Module Out:
LM XMIT -> 7404 inverter -> 5V to 3.3V -> Netduino RCV

I also tried (since the Netduino RCV is 5V tolerant):
LM XMIT -> 7404 inverter -> Netduino RCV

Logic Module In:
Netduino XMIT -> 3.3V to 5V -> 7404 inverter -> LM RCV

Can you think of anything I missed, or is there any issue with either the 74LS04 or the logic level converter?

I apologize for the thread hijack, but I figure this may be useful to others going down a similar path...

That seems reasonable. But even simple stuff like this can have a million things go wrong. Do you have a digital scope? You could monitor the bus and know whats up very quickly that way. If you only have a DMM you could at least detect idle state voltage and possibly see data flicker through on both sides.

Are you making sure to connect all the grounds together especially the 7404? And bypassing it? What are you powering the 7404 with?

If you havent made a schematic for what you are attempting I would start one.

I take it you cant configure the arduino to have inverted logic on its serial port? What processor does it use? Are you allowed to access the processor directly to configure it how you want or does the arduino stuff prevent that?

[RoadWarrior222]

For inverting the signal, I had tried using a Motorola 74LS04N inverter chip, with one of the inverters (NOT gates) used for the xmit, and another used for the rcv. Is this a valid configuration?

Can you think of anything I missed, or is there any issue with either the 74LS04 or the logic level converter?


I apologize for the thread hijack, but I figure this may be useful to others going down a similar path...

I think the drive current of an LS (Low power shottky) part is weak, however should trigger a logic high on 2V input so if you've got 5V tolerant incoming you should be good there, but I'm thinking you might need a good solid 50+mA to drive the comms and you might only be getting 5 or 10 outa that.

[RoadWarrior222]

but just a thought before you get another part, hook up all 5 gates in parallel for TX, and just the one for RX

[csxtra]

That seems reasonable. But even simple stuff like this can have a million things go wrong. Do you have a digital scope? You could monitor the bus and know whats up very quickly that way. If you only have a DMM you could at least detect idle state voltage and possibly see data flicker through on both sides.

Are you making sure to connect all the grounds together especially the 7404? And bypassing it? What are you powering the 7404 with?

If you havent made a schematic for what you are attempting I would start one.

I take it you cant configure the arduino to have inverted logic on its serial port? What processor does it use? Are you allowed to access the processor directly to configure it how you want or does the arduino stuff prevent that?

Unfortunately, I don't have a digital scope (I looked into buying one when I was trying to get this to work, but life got in the way and I had to just fall back to the RS-232 approach due to time constraints).

I did tie all of the grounds together (signal ground out of the LM, Netduino ground, 7404 ground, and Level converter grounds). I powered the 7404 and the 5V side of the logic converter from the 5V power pin out of the Netduino, and powered the 3.3V side of the logic converter from the 3.3V power pin out of the Netduino.

I'll revisit my circuit and see if there is something I missed and draw up a crude schematic.

I'll also do some research into what the options are for inverting the logic on the Netduino UART. The Netduino uses a STMicro STM32F2 processor, but since it runs the .Net micro framework, it will probably be a bit harder to get to the base hardware...sometimes abstraction layers are nice, in this case, it may prove to be a PITA.

Thanks for your help, at least I know that I was on the right track and not way off base. Maybe after SDAC I can rationalize getting a cheap scope/logic analyzer and look into this further.

[acannell]

Unfortunately, I don't have a digital scope (I looked into buying one when I was trying to get this to work, but life got in the way and I had to just fall back to the RS-232 approach due to time constraints).

I did tie all of the grounds together (signal ground out of the LM, Netduino ground, 7404 ground, and Level converter grounds). I powered the 7404 and the 5V side of the logic converter from the 5V power pin out of the Netduino, and powered the 3.3V side of the logic converter from the 3.3V power pin out of the Netduino.

I'll revisit my circuit and see if there is something I missed and draw up a crude schematic.

I'll do some research into what the options are for inverting the logic on the Netduino UART. The Netduino uses a STMicro STM32F2 processor, but since it runs the .Net micro framework, it will probably be a bit harder to get to the base hardware...sometimes abstraction layers are nice, in this case, it may prove to be a PITA.

Thanks for your help, at least I know that I was on the right track and not way off base. Maybe after SDAC I can rationalize getting a cheap scope/logic analyzer and look into this further.

You can probably nail this with just a meter. Draw the schematic, including pin numbers and wire colors. Post it here (phone snapshot fine). Double check your inverter connections are correct. Measure all the voltages in the circuit. Confirm the input and output voltages of the inverter are opposite (they should ALWAYS be opposite unless something is wrong).

How many 7404 chips do you have? Where did you get them? Make sure its not getting warm to the touch, i.e. blown.

Post up a pic of your circuit connections.

I take it your whole setup is known working, known good, using your previous rs232/ttl setup..right? Try hooking it up that way and make sure everything still works.