Microsquirt Module Stepper IAC connexion

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Manu
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Microsquirt Module Stepper IAC connexion

Post by Manu »

Hello,

I'm currently design a new PNP device for Peugeot 306RS car. This is an 4 inline - 16V - 2.0L which is common in France and well used in Rallye. On this PNP I have to use sequential injection and ignition.

So I have to keep PT6 and PT7 for injection and can't use it for IAC Stepper. With Microsquirt and Microsquirt Module we can now change IAC control pins for another. OK, but :

When we select SPAREADC2,FIDLE,SPAREADC instead of IACEN,PT6,PT7 with a Microsquirt Module to drive H-Bridge, does ?
  • SPAREADC2 = IACEN
  • FIDLE = PT6 = PHASE1 = IAC1
  • SPAREADC = PT7 = PHASE 2 = IAC2
In this case I guess we need to add pull-up resistors, or some signal conditioners to use ADCs/FIDLE with A4970 chipset. Is there any documentation about that ? If not, can a developer write it as this case is something users should use ?

Thanks for advices. Regards,
Manu
I can supply, repair or upgrade Megasquirts in FRANCE.

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Manu
Master MS/Extra'er
Posts: 723
Joined: Mon Feb 15, 2010 4:57 am
Location: Alès - France
Contact:

Re: Microsquirt Module Stepper IAC connexion

Post by Manu »

Hello,

I'm now at the end of the project and still stuck with those pins. Can someone help please ?

Regards,
Manu
I can supply, repair or upgrade Megasquirts in FRANCE.

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dontz125
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Re: Microsquirt Module Stepper IAC connexion

Post by dontz125 »

The MS2 DC schematic is covered on 2 pages in the MS2 hardware manual; this page shows the pinout of the stepper chip with its resistors and caps. The A4997 is pin-for-pin identical to the SMD version of the previous device.

*Don't* use the diagram from the DIYA site; it show the old TH version, which (quite unusually) had a very different pinout vs the SOIC package.
Last edited by dontz125 on Sun Jan 15, 2017 9:24 am, edited 1 time in total.
QuadraMAP Sensor Module -- PWM-to-Stepper Controller -- Dual Coil Driver
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Manu
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Posts: 723
Joined: Mon Feb 15, 2010 4:57 am
Location: Alès - France
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Re: Microsquirt Module Stepper IAC connexion

Post by Manu »

Hello Don,

Thank for your reply. Sadly it didn't answer the question as I already have schematics and even working PNP with A4970 chipset. But all use the standard MS2 output so there is no big thoughts to deal with here. Just route signals and it work. But PT6,PT7 and IACen are coming straight from the processor, without any component beside the processor.

Now I have to use different pins than standard ones (SPAREADC2,FIDLE,SPAREADC) and for this I can't find any documentation. As those pin HAVE components beside the processor, I'm quite sure I have to do some electronics between them and A4970. First thing to know is : which pin connect to what (phase 1, phase 2, enable) ? And then, HOW to use SPAREADC2,FIDLE,SPAREADC to drive an A4970 ?

Regards,
Manu
I can supply, repair or upgrade Megasquirts in FRANCE.

Image
https://www.megasquirt.fr
dontz125
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Re: Microsquirt Module Stepper IAC connexion

Post by dontz125 »

Manu wrote:Now I have to use different pins than standard ones (SPAREADC2,FIDLE,SPAREADC) and for this I can't find any documentation. As those pin HAVE components beside the processor, I'm quite sure I have to do some electronics between them and A4970. First thing to know is : which pin connect to what (phase 1, phase 2, enable) ? And then, HOW to use SPAREADC2,FIDLE,SPAREADC to drive an A4970 ?
Ah! Understood. Don't worry about the filter circuit components on the ADC pins; the frequency isn't fast enough to make a difference. I would suggest you DO need a pull-up on the FIdle pin. As to the pin selection, the list in your first post looks correct to me:
  • SPAREADC2 = IACEN
  • FIDLE = PT6 = PHASE1 = IAC1
  • SPAREADC = PT7 = PHASE 2 = IAC2
QuadraMAP Sensor Module -- PWM-to-Stepper Controller -- Dual Coil Driver
Coming soon: OctoMAP Sensor Module
TTR Ignition Systems
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