LM-2 Issues solved with full AFR range 7.35 to 22.39 with no band-aid fixes.

Hi to all.

I had the reading stability issue when you connect the LM-2 to EIO plug on VCM Scanner,
The LM-2 Analogue Out 1 this is the issue, it is Pulse Width Modulated not true analogue causing the readings to go from min to max very fast, i see some have tried ms filter and lower the effective AFR range to try and stable the readings.
Ground offset is NOT the problem either.
I found none of these band-aid fixes viable so,
I have built a Digital to Analogue converter, which has completely solved the problem.
It is now as stable as and accurate from 7.35 to 22.39:1 AFR.
What ever is on the screen of the LM-2 is also on the screen in VCM Scanner.
So problem fixed and solved..

While I was at it I made Exhaust Temp circuit to read and display EGT and a dial knob to display o-5v to log any audible knock, on VCM Scanner, I thought nice add on's for data logging..

Base Converter 1 channel of data converted.
Attachment 81400

Attachment 81139Attachment 81140Attachment 81141
Tomorrow when its light and warmer, i will do some more tests and share results here.

Well today I tested this thing..
here is the results.
Attachment 81181

My Serial log from the microcontroller,
Attachment 81182

It would be a lot easier if HP just used software Analog to digital converters instead of hardware ones on there inputs, and this issue would not happen.

It would also be easier if Innovate used a real hardware digital to analog output instead of pulse width modulated simulated analog, and this issue would not happen.

A=Analog
D=Digital
PWM = Pulse Width Modulation
HP = Pro interface with VCM Scanner

AFR Sensor = A
LM-x Meter = D
LM-x Output is D (PWM is simulated analog)
HP input is A (A/D converter) samples the input with PWM software.
so the HP Software sees this input as 0-5-0-5-0-5-0-5v(PWM) from LM-x output


So my converter takes the PWM from LM-2 as D and or A signal and converts it via a software controlled D to A converter chip to output real A to HP.

code..

//DAC_MCP4725
// Input 0-5v PWM or Analog on (A1) output DAC out 0-5v linear.
#include <Wire.h>
#include "i2c.h"
#include <Adafruit_MCP4725.h>
Adafruit_MCP4725 dac;
#define DAC_RESOLUTION (8)
int AFRSignal;
void setup()
{
dac.begin(0x62);
}
void loop()
{
int AFRSignal = analogRead(A1);
float DAC = map(AFRSignal, 0, 1023, 0, 4095);
dac.setVoltage(DAC, false);
delay (10);
}

This is what converts the LM-2 data to suit HP input
Hardware is
1 x Arduino UNO
1 x DAC MCP4725
1 x Box
3ft 4 core wire
will give you 1 channel of converted data.Attachment 81401

Nice exactly what I need. PM sent.

Need more Inputs on HP Interface 4 just isn't enough for me, the VCM Scanner software is great just need to be able to input more data to it for logging.
So Far I have
1- AFR
2- Knock
3- EGT
4- G-force - for mobile work
then I run out of inputs

need to add

5- weather correction
6- dyno load- when on the dyno
7- Oil Temp - some cars this can be logged through OBDII

Need more 0-5v inputs, and I could log all this data on VCM Scanner my preferred logging system.

arduino's analog out is PWM also. That DAC just puts a PID loop on the output to make sure it matches what is commanded.

The issue must be in innovative's frequency used and or output buffer/filter.

yes Aurduino is PWM out, the DAC makes it a linear voltage out, im guessing the PID is the number 0-4095, which creates the voltage out.

TO to free up an analog input, can you use the serial output from the LM2? I have an LC2 and I use only the serial output on that just to avoid any ground offset issues.

Quote:

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Originally Posted by Philbar715

TO to free up an analog input, can you use the serial output from the LM2? I have an LC2 and I use only the serial output on that just to avoid any ground offset issues.

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Need more inputs on HP interface not LM-2, one of these converters would fix your so called ground issues as well,

Quote:

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Originally Posted by ModchipMan

Need more inputs on HP interface not LM-2, one of these converters would fix your so called ground issues as well,

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I was saying, instead of using an analog input on the HPT interface for the wideband why dont you use the serial output on the LM2 to log the wideband in scanner? (dont use the analog output on the wideband at all, serial output only. The serial output connects directly to your laptop). That would free up an additional analog input on the HPTuners interface.

Quote:

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Originally Posted by Philbar715

I was saying, instead of using an analog input on the HPT interface for the wideband why dont you use the serial output on the LM2 to log the wideband in scanner? (dont use the analog output on the wideband at all, serial output only. The serial output connects directly to your laptop). That would free up an additional analog input on the HPTuners interface.

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Sounds Interesting..
How do you get VCM Scanner to log a serial input..?

arrh found it add serial channel

Quote:

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Originally Posted by ModchipMan

Sounds Interesting..
How do you get VCM Scanner to log a serial input..?

arrh found it add serial channel

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Yep, it supports the LC1 and LC2 and a few other serial widebands. You do have to use a serial to USB adapter in to your laptop unless your laptop has a native serial port. However its trivial to use a USB hub so you only have one USB connection going to your laptop while logging.

With serial input you dont have to worry about any of the issues you described in this thread. You can also log the status of the controller (i.e error codes if the sensor goes bad) and you can log it in lambda or AFR (or both like I do).

Serial is to messy, I keep going down this road..

So how does someone that is not an electrical engineer make the LM2 work with HP tuners? Because I'm lost here.

Quote:

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Originally Posted by Mystery Bird

So how does someone that is not an electrical engineer make the LM2 work with HP tuners? Because I'm lost here.

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I have it wired to my Pro-link and it works perfect.

Quote:

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Originally Posted by Jeff7577

I have it wired to my Pro-link and it works perfect.

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Guess it's time for me to upgrade?

I have an LC-2 and I need help. I have connected as all info I found said and in my chart and channel it shows 7.7- 10.8 while my gauge reads 14.2. I don't know how to get this to chart correctly. Can someone please help me understand what ive overlooked or done wrong?Attachment 90014