OBD MPGuino gauge

[Magister]

Yeah thanks, I fried my ELM327 months ago and was not able to fully debug the code!

[edllew]

Sorry to hear your ELM327 broke. I am hoping I don't do the same to mine...

I solved my engine off/engine on problem previously mentioned, so I am good to go with the code, and will now focus on containing all my wires in proper cabling and a box.

In all, to get the code running for my 2004 Pontiac Vibe, I made three changes to r193:

1.
elm_init(): Serial.begin(38400); (was 9600)

2.
elm_init(): removed command "ATDPN" through the end of the function, which removes the ISO-9141 SET HEADER command.

3.
loop(): in the non-useECUState part, following the call to save_params_and_display(), 3 lines added, which put the ELM in a state which makes it work for me on engine restart:
elm_command(str, PSTR("ATWS\r")); //warm start
delay(1000);
elm_command(str, PSTR("ATE0\r")); //echo off

These tweaks are not meant to be general solutions. They are just what is working for me, and might help someone else too. So I wouldn't recommend modifying the code base with them without a bit more investigation (like why the SET HEADER was there, and why it doesn't work for me). I'll pass on anything I learn.

The loop() code uses a few global variables that I failed to understand, and the two halves of loop() (one for useECUState and on for not) may have diverged over time. Which is to say that my ELM warm-start solution in loop() may cause other side-effects and problems.

[dar]

I used Si9243 with success. For me it was much easier to find instead of MC33290.
It's communicate with WW Passat 1.8 1999.
P.S. It is necessary to check DB9M 1(signal ground) for ground.
If no - connect 1 and 2 together.

[py7rjs]

I could only get hold of a Si9243, dar can you post a link to your modded code or give me some hints as to what needs tweaking. Any tips?
Kind Regards
py7rjs

[dar]

I used 187 without code modification (protocol ISO 9141).

+12V-------------------------------------------->9 Vbat
....................______...I--------------------->8 L
Pin 0 <-------I 1...8 I--I...I--1N4004 diode-->9 Vbat
Rx................I 2...7 I-----+--560R 0.5W--I
Pin <-100R--I 3...6 I----------------------+->4 K
+5V
Pin 1 <-------I 4...5 I------------------------>1 GND
Tx.................______ Si9243
Pin 0v <---------------------------------------->2 GND
GND
............dots is spacing..
I added 100R resistor and diode (1N4004) for protection.

[eimix]

Yes it looks like Si9243 does not need any code modification, unlike Si9241 discussed some time ago.

Just not understand why 6 and 7 pins are connected with 560R?

[dar]

For information about Si9243 -> VISHAY AN602 "Driver ICs for Automotive Diagnostic Communications Meet ISO 9141 Standards" (->google.com).
Resistor 560R 0,5W is between K-line (6) and Vbat (7) (Si9243AEY) alike 510R between 1 (Vbat) and 4 (ISO) leg of MC33290.
I'd used 560R instead of 510R, because found in few USB-KL-adapters. Sometimes there is adjustment (510R+ potentiometer 0-2000R).
I like it

[DJ_SpaRky]

Well, My OBDuino setup is acting weird, I updated to v193 and now all it displays is random hex values. I have checked the code and reloaded, I have also tried loading the generic (unmodified) code, I have also loaded the EEPROM Clear code and then reloaded, all to no avail. I am also getting display doubling and scrolling issues. Please assist. (I am using a MC33290 Chip and a 20x4 LCD)

EDIT: Got it working, had to disconnect everything form the 'duino and use only Arduino software to edit and upload. Still having doubling issues though, but I will search and maybe make a new thread for that. Thanks.

[dar]

Hello,
Now i'm trying to add SdCard support, but there are some problems.
1. Then used Obduino32k (ver. 194) with (// define useSDcard) - i get many errors ( as, "364: error 'byte' does not name a type", ....). Adding #include "WConstants.h solved some problems, but not all.
Then went to previous version (v.193) - withtout CDcard support (// define useSDcard)- it is posible to compile and upload. (Now trying in the car).
2. But then trying Obduino32k with SDcard support (both version 193, 194), compilation goes O.K. ( Binary sketch size: 30050 bytes (of a 32256 byte maximum)), but I can't to upload to arduino.
Whitch version of "FileLogger" library is used?
Thanks for answers.

[eimix]

I used arduino_22
FileLogger was V0.6

Is your arduino version same?

did you uncomented
#include <FileLogger.h>?