My LCD screen project, boost, WBO2, Knock, etc

[fastbikes76]

Sorry for all the short replies but I post from the car as I see what's going on.

I did notice when connected once all figures were shown as a max which decreased when I revved the car (almost working opposite )

The pic below is on tick over yet it shows 7500rpm, 33 psi boost etc etc


ImageUploadedByTapatalk1378231139.662172.jpg


Oh and I can't work out what I did right too make it connect and log, but I can't get it too connect again. I've tried connecting immediately after LCDBC connects, tried waiting a couple I minutes, tried connecting evoscan first and then starting car... I just can't get my head around why it suddenly worked for a few minutes.


What I do know is it was awesome being able to log afr and boost through the unit

[Unlogic]

Oh and I can't work out what I did right too make it connect and log, but I can't get it too connect again.

This seems exactly like the problem I had when trying to update my unit. I tried to connect at least 100 times and they all failed except one where it actually managed to connect for a few short seconds.

[fastbikes76]

This seems exactly like the problem I had when trying to update my unit. I tried to connect at least 100 times and they all failed except one where it actually managed to connect for a few short seconds.

Yeah we definitely all having the same issues so it must be the box rather than the cars. I'm sure Blackstealth is on the case though

[Unlogic]

Yea I'm sure he'll figure this out given how many units he must have built by now.

[fastbikes76]

Yea I'm sure he'll figure this out given how many units he must have built by now.

Ok I think I have Sussed out the evoscan connection.

First try the normal route by starting the car and once the LCDBC is connected try connect evoscan. It probably won't connect.

Now try this ..after you have tried connecting the normal way turn the ignition switch OFF, start logging on evoscan and it should connect straight up .... Once it's connected once, stop the logger and start the car. The LCDBC should connect up fine and then if you start evoscan it should connect too.

If you leave evoscan connected the LCDBC WON'T connect too the car when you start it. It does its 4 attempts and then gives up.

It also seems once you have got evscan to connect to the LCDBC it will work flawless no matter what method you use to connect. After leaving the car for a while though you are back to square one of NO connecting unless you first try connect with ignition on, and then connect while the ignition is OFF .

Very hard to explain but I have spent a out two hours working out the 'method' . I can get it too work after a couple of minutes playing with IGN.

[Unlogic]

Great research! I'm sure that it will help Blackstealth diagnosing why the expansion serial port is so funky.

[fastbikes76]

Great research! I'm sure that it will help Blackstealth diagnosing why the expansion serial port is so funky.

Yup I now have it 100% confirmed. After spending 3 hour min I can do it every time now.

1. Start car
2. Fit USB cable to laptop
3. Fire up evoscan and try connect
4. Select 'stop data logger'
5. Switch IGN off
6. Select 'start data logging' immediately
7. Once evoscan has connected select stop again
8. Start car and wait for LCDBC to connect
9. Start evoscan logging
10. Smile and enjoy lol


I have just done this 5 times and it is the ONLY way to connect.

Hope this helps

[Unlogic]

Thats excellent!

I can't verify if the works with my box yet however due to the fried MAX232 chip in my unit.

Could you take your car for a ride while you are logging with evoscan and check with which values you get right before the LCDBC disconnects from the ECU?

Maybe we can find a pattern there.

[fastbikes76]

Thats excellent!

I can't verify if the works with my box yet however due to the fried MAX232 chip in my unit.

Could you take your car for a ride while you are logging with evoscan and check with which values you get right before the LCDBC disconnects from the ECU?

Maybe we can find a pattern there.

I will be able too tomorrow after work. I could be bothered to move my van and wife's car to get mine out tonight lol.

I am 100% now I can get Evoscan too connect in the manner I worked out so hopefully I can go out logging tomorrow and see if anything shows up when the LCDBC disconnects. For some reason though I've not had any disconnects tonight while sitting in the car testing, Could just be I haven't left it long enough though.

Progress is being made

[BlackStealth]

Using a circuit simulator on the OBD2/MUT transistor circuit and I discovered R1 works best at 0 ohms, which is equivalent to not needing it at all. This produces a low signal that is much closer to 0 volts. I went online and searched for other OBD2 circuits and made comparisons, and they too have discarded R1, so I feel good about that confirmation. This transistor/resistor version will produce a low signal voltage much lower than the OBD2 chip, which means it will resist electrical noise better.

Here is the OBD2/MUT adapter I am working on. It includes a 33uH and 82pF components for a band pass filter to further reject noise. I will have these PCB made ASAP.



Other comments:
(1) When you install FTDI drivers, you will need to reboot windows, it won't work correctly until you do.
(2) When you want to use Evoscan, first allow LCDBC connect to the ECU and then use Evoscan to connect. Should the LCDBC get disconnected from the ECU, Evoscan will continue to receive data from the LCDBC; the data will be static except for Boost and WBO2 info. When LCDBC attempts to reconnect to ECU it will ignore Evoscan requests at that moment and then resume.
(3) When you adjusted the screen refresh rate to 2, this already indicates there's a problem with communication between LCDBC and ECU. If the LCDBC cannot get info from the ECU, it won't have anything to update the screen with.
(4) Previous versions of LCDBC used Texas Instruments MAX232EIN chips and never had a problem with those. Now that I use Maximum MAX232EPE+ chips we have our first bad chip, and hopefully last.
(5) Evoscan calculates Coolant and Air temperatures incorrectly for our cars; LCDBC uses an internal table to report correct values.
(6) "Can I replace the 2N3904 with a BC337 and the 2N3906 with a BC327?" Yes.