DIY digital A/F ratio gauge **PICS ADDED**

[Turbo383TA]

Well the link isn't working for me, but I can probably tell enought by the picture.  I'm with Mystang in thinking that a scan tool is a little over my head as well.

As for the idea of running two regulators, that's about the easiest way I can think of doing it.  I assume the display has an LED backlight, so it will use basically no electricity and pretty much never wear out.  I would probably try it first with the backlight on all the time and see how it does.  You could always put a switch on it, but then you would have to flip it when you turned your lights on.

All it really does is display data read by the ecu. Ill see if I can come up with some easy ideas for it..

[gobtool]

Well that doesn't sound too bad.  Hey Mystang, I sent an email to Lascar to confirm what resistors we need to use.  I believe they're gonna say to use a 1M in series and a 10K to ground like we discussed.  I think were gonna use DP2 as well, since there's 4 digits total.  Then it should read like 14.70 for an input of 1.47V

[mystang]

Well that doesn't sound too bad.  Hey Mystang, I sent an email to Lascar to confirm what resistors we need to use.  I believe they're gonna say to use a 1M in series and a 10K to ground like we discussed.  I think were gonna use DP2 as well, since there's 4 digits total.  Then it should read like 14.70 for an input of 1.47V

i thought it was a 3 digit readout max though?   So it would have to be dp1 if we can get the decimal place "scaled" right

[gobtool]

According to the manual, it has 4 digits.  It showed examples of like 1.999, 19.99, and 199.9 for the different decimal places.  I assume that if you had it set on DP1, it would show you 19.9 and probably just not light up the very first number. 

I haven't heard back from them yet, but I'm almost positive about using the 1M and series and 10K over to ground.  The voltages listed in the chart in the manual was the maximum voltage you could put into the display.  If you set it with those resistors, the max voltage is 20V, and the max voltage gives a readout of 200.  Therefore, if you put 1.5V in, it should read 15.

[turbo'dnotch]

I'm planning on getting a LC-1 shortly, how are you guys coming along on this. I'm no electronics expert but I can follow directions pretty dam well. Can you guys get a parts list together and approximate cost for this.

[Millhouse]

http://www.innovatemotorsports.com/forums/showthread.php?t=1574&highlight=LED+display

Enjoy 

[turbo'dnotch]

So all thats needed is that particular gauge, program the LC-1 output for the gauge as well as the megasquirt. Making sure to use the same grounds, and thats all? Cant be that simple? What am I missing, no mention of resistors or anything

[mystang]

I'm planning on getting a LC-1 shortly, how are you guys coming along on this. I'm no electronics expert but I can follow directions pretty dam well. Can you guys get a parts list together and approximate cost for this.

Well i have ordered the enclosure which arrived here yesterday evening i am still waiting on the resistors which should be here today and the display which may be here today or friday, then i need to head over to radio shack and pick up some odds and ends.  As for the ouputs yes you just run one of them to the megasquirt, becuase the lc-1 has to analog outputs(1 and 2)  factory one is set as a wideband 0-5 volts and the other as a factory narrow band 0-1 volt i believe it is.  You can change this very eaisly just by installing the software that comes with the lc-1 and communicating with it.  The two ouputs are completely seperate from each other, but i would try to ground the "display" that we are working on to the engine block to prevent ground offsets.  Time will only tell, but if i get all of this stuff today i will build it tommorow and see if it does exactly what we anticipate.



As for the enclosure listed in the first link it is much smaller then i had though which is good, because it can be mounted almost anywhere even under your radio mostl likely if you have an aftermarket one with a "cubby hole" or what ever they call it, if not you could eaisly put it between your steering wheel and your instrument cluster.  I think i am going to take an autometer gauge that i took apart and was using for the lc-1 led light and calibration switch and reuse that and mount the display into that depending on if it will fit or not.

[turbo'dnotch]

As for the enclosure listed in the first link it is much smaller then i had though which is good, because it can be mounted almost anywhere even under your radio mostl likely if you have an aftermarket one with a "cubby hole" or what ever they call it, if not you could eaisly put it between your steering wheel and your instrument cluster.  I think i am going to take an autometer gauge that i took apart and was using for the lc-1 led light and calibration switch and reuse that and mount the display into that depending on if it will fit or not.

We might be talking about the same thing here, but I am asking if you just hook this to one of the outputs on the LC-1, program and call it a day?

[flyinhillbilly]

gobtool, would you consider making me one of these for a fee? if so pm me with a price, thanks.

[mystang]

We might be talking about the same thing here, but I am asking if you just hook this to one of the outputs on the LC-1, program and call it a day?

Ahh yes and no the outputs of the lc-1 will have to be reprogrammed which is simple to do just install cd hook up computer to lc-1 type in new values and hit program, but essentally yes

[mystang]

gobtool, would you consider making me one of these for a fee? if so pm me with a price, thanks.

Are you refering to the display in the original thread, or the one that gbtool is using the "red number" or the one that me and him are trying to make a prototype of.  This would be the black lcd readout like you would see on a digital volt meter, but with a green backlight,  we have to see if this one will work first as i am waiting on some resistors and the display to show up to my door.   Also on another note if this works out there are also blue backlight displays that you guys can use.

[flyinhillbilly]

the original would suit me fine, i'm just looking to save some money on the guage part of it for my racecar, being poor white trash sucks

[Big Studly]

This might have been mentioned because I didn't feel like reading all the responses, but I got a glowshift gauge that has an a/f "light show" type gauge and a digital volt meter built into one for about $40.  I am going to run one LC-1 output to the lights and the other to the volt gauge so I have a number and a light.  I only did it this way so I could have a numerical readout and match a boost gauge.  I wanted to have a matching pair because I am anal.  I tried to do a lot of reserach, but I am still new to the turbo world so this might not be the best option, but it was one I was satisfied with.  For about the price of an AEM wideband I got the LC-1, a boost, and a/f gauge that should work just like any other wideband with a digital display.

[Kerrdogg]

I guessing the enclosure is a Motorcraft oil container?

[TwinTrouble]

So has anybody got a guess about what I used as a enclosure?

Tape measure?

[gobtool]

I guessing the enclosure is a Motorcraft oil container?

No, but damn close.  It's a Marvel Mystery Oil container.

gobtool, would you consider making me one of these for a fee? if so pm me with a price, thanks.

I'll look into it.  If I win those two displays on eBay that are like mine, I'll be able to make up a couple of them.  I'm not sure of the price, but it will be pretty cheap.  I'll let you know when I get number.  If I make you one I'll get a real enclosure and all to put it in.

We might be talking about the same thing here, but I am asking if you just hook this to one of the outputs on the LC-1, program and call it a day?

Yeah like Mystang said, you'll have to reprogram one of your outputs on the LC-1.  You'll probably need two resistors as well to get it to read right.  For the type display that is used in the very first link, you need a 1M resistor and a 10K resistor for it to work right.  You also need a voltage regulator to supply the 5V that most displays operate on.

[mystang]

Allright i made the circuit board and got the enclosure and did the necessary trimming for heat sink etc hook up battery to it and i am getting the correct readings, so now i am just waiting on the display to show up and when that happens i am very sure that it will work.

[mystang]

It works  i got the display to work and apparently me and gbtool were wrong on the second resistor so the decimal point is off but that is as simple as swapping a resistor so about two minutes and it should be correct.  The display works flawlessly i will see if i cant get some pics tommorow as it is kind of late here tonight and i have a test tommorow i need to study for.  See if i cant get the girlfriends digital camera compared to my camera phone.  It turns out that the display had been here at my apartment complex since thursday but the idiots at the font desk could not find it  so i called the company today and they said it had been delivered the first which was thursday and said so and so signed for it and i had been waiting on this thing    ohh well got it and it works so all is good.

[gobtool]

Glad to see that you got it working.  So what is the display showing now with 1.5V input.  Any idea if you need to go up or down on the resistor? 

[ChevyIIMan]

You could always just Drop $70 on a Moates "O" Meter. Does AFR/Lambda/Universal display, data storage, etc. Fully user configurable through two easy-touch buttons.

Here is the instruction guide for the O-Meter so you can read about all the features:
http://www.moates.net/zips/ometer_guide.pdf

Here is a video of the O-Meter in action:
http://www.moates.net/zips/ometer_1.mpg

[gobtool]

Yeah, it looks like that would work good.  Is anybody on here using one?  I couldn't find a picture of it on their website.

Edit:  Nevermind, I watched the video.  That thing is small.

[ChevyIIMan]

Ive got one ordered. With an LC-1 im going to use it in conjunction with my Autometer LED gauge that is already installed.

[Millhouse]

Seeing all these posts makes me like my XD-16 just that much more!  If you need to re-cal your wideband you just push the button on the gauge.

 

[gobtool]

Yeah, but the LC-1 should have came with a calibration button and led anyway.  To recalibrate my LC-1, I just hit the button mounted on my dash.

Those XD-1's are nice though.  Just a little too expensive for me.