Author Topic: Adding 2nd wheel speed input (SCL)  (Read 13968 times)

Offline NOTORIOUS VR

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Adding 2nd wheel speed input (SCL)
« on: August 20, 2015, 06:54:13 pm »
Just looking for some verification on this topic before I make some modifications...

Can someone tell me if what I've drawn up here will be ok?  I've made this sketch according to the information I've got from speaking with Marcell. Just want someone to verify/back it up.

Thanks


Offline Kamuto

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Re: Adding 2nd wheel speed input (SCL)
« Reply #1 on: August 20, 2015, 09:57:57 pm »
diode in wrong place and you need one more resistor
just look at sec trig hall circuit
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Offline NOTORIOUS VR

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Re: Adding 2nd wheel speed input (SCL)
« Reply #2 on: August 21, 2015, 07:30:35 pm »
diode in wrong place and you need one more resistor
just look at sec trig hall circuit

odd...

this is what Marcell wrote to me via email:

Quote
Needs to be connected.

wheelspeed2 is the (non-GND) SCL pin right next to SDA pin (third trig), SDA seen on bottom of : http://vems.hu/vt/help/v3/v3_camshaft_angle_control.html

4k7 or 10k resistor, and diode protection to 5V recommended (normal diode like 1n4007 in rescuekit: stripe-marked cathode on +5V, diode anode on SCL).

(alternatively: 5V1 zener to GND, in that case zener stripe-marked cathode is on SCL input; zener anode on GND)

Offline PeepPaadam

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Re: Adding 2nd wheel speed input (SCL)
« Reply #3 on: April 29, 2016, 08:06:09 am »
Resurrecting the topic.

I need to add 2nd wheel speed and plan to use Continental FlexFuel sensor which should have square wave output (pulls 12v to GND).

Can anyone verify the 2nd wheel speed schematic?


« Last Edit: April 29, 2016, 08:08:59 am by PeepPaadam »

Offline MWfire

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Re: Adding 2nd wheel speed input (SCL)
« Reply #4 on: April 29, 2016, 12:05:11 pm »
What version of board do you have?
On v3.8 filter and protection is embedded in PCB.

Offline PeepPaadam

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Re: Adding 2nd wheel speed input (SCL)
« Reply #5 on: April 29, 2016, 02:56:40 pm »
It is V3.8b

Offline MWfire

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Re: Adding 2nd wheel speed input (SCL)
« Reply #6 on: April 29, 2016, 03:08:51 pm »
Than you have all elements for filter on pcb.

Offline PeepPaadam

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Re: Adding 2nd wheel speed input (SCL)
« Reply #7 on: April 29, 2016, 04:07:08 pm »
Even if it has 12v output that is pulled to GND?

Offline Mads Lund

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Re: Adding 2nd wheel speed input (SCL)
« Reply #8 on: April 29, 2016, 04:10:01 pm »
I've just made 2 wheelspeed input on my V 3.8

If you use only one lambda is the install straight forward. I you (like me) use 2 lambda's is it a bit more tricky.

WS2 is very simple, just use the hole on the first pic with white/blue wire.

WS1 is easy if you dont use lambda 1. In that case just shorten the 2 pads on pic 2 just below the resistors where i have the blue wire. then WS1 logic input will go to the EC18 connector. If, like in my case the EC18 pin is used for lambda 2, then do you have to get connectin on the resistors like I have done. DONT USE the lowest of the 4 holes above (like on older boards. In that case do you connect directly to the ecu without any protection.

If connected correctly are there a protection resistor and diode on the cpu. So it wont fry if you by accident connect +12v on the input.

Remember WS input's are for Hall/logic level 5V. If your sensors are VR, use the VR to hall converter pcba's. These can also divice the frequency, the CPU on the board is a old steam engine, and have limited speed. So WS frequency must be rather low. I'll try to find my test results, but as a guide, do I have 100 pulses per wheel rev, and that need a x8 divider to become usable.




Offline PeepPaadam

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Re: Adding 2nd wheel speed input (SCL)
« Reply #9 on: May 02, 2016, 08:14:02 am »
Thanks!

But the sensor is in fact 12v signal, it is not VR. So it is safe to feed the CPU with this signal on v3.8 board since it has the protection in SCL pin?

Offline Mads Lund

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Re: Adding 2nd wheel speed input (SCL)
« Reply #10 on: May 02, 2016, 09:53:56 pm »
Yes a 12V Hall sensor is no problem. But be sure to wire like on the pictures. By doing so, will you have a current limiting resistor and a 5V zener diode to step the 12V down to 5V.

But dont use the lower of the 4 holes next to the cpu directly, doing so will fry the cpu, using the EC18 pin, and shorting the path will ensure you get the right protection. Only in dual lambda setup's are there a risk.

BTW the second WS input pin, that on V3.6 was a direct cpu connection, is on 3.8B changed, so it have a resistor and a zener. And this channel can't be wired wrong.

Offline PeepPaadam

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Re: Adding 2nd wheel speed input (SCL)
« Reply #11 on: May 03, 2016, 06:11:07 am »
Thanks a lot!

Offline NOTORIOUS VR

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Re: Adding 2nd wheel speed input (SCL)
« Reply #12 on: February 28, 2017, 07:50:38 pm »
I'm reviving this topic.

I would love it if someone could work around the riddles and draw a simple connection diagram for WS2 on a v3.6/7 board.

The poor documentation for something as important as this really doesn't make any sense to me.

given this info:
Quote
4k7 or 10k resistor, and diode protection to 5V recommended (normal diode like 1n4007 in rescuekit: stripe-marked cathode on +5V, diode anode on SCL).

(alternatively: 5V1 zener to GND, in that case zener stripe-marked cathode is on SCL input; zener anode on GND)

Can someone please make a quick schematic/diagram of what/how this is supposed to be put together?  I really do not want to kill an ECU because of this.

This: http://vems.hu/download/v3/doc/assembly/v3_protected_wheel_speed_connection.png

Doesn't do me any good because it's certainly different to was Marcel explained above.

Thanks!

Offline NOTORIOUS VR

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Re: Adding 2nd wheel speed input (SCL)
« Reply #13 on: April 07, 2017, 04:07:24 pm »
As an update to this all, this is the way I decided to do it on my own ECU for now/testing...






Protection circuit...


Offline gdt

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Re: Adding 2nd wheel speed input (SCL)
« Reply #14 on: June 30, 2017, 01:41:59 pm »
As an update to this all, this is the way I decided to do it on my own ECU for now/testing...






Protection circuit...



Did this work for you?

Also, what pin on the EC18 CONNECTOR does the wheelspeed in map to (yellow wire in your set up)?

thanks!