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G5 Ambient Temperature Sensors

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I have been trying to get two ambient temp sensors working from a 2005 G5. So far no luck.

They are:

http://www.welovemacs.com/8201516a.html

and

http://www.welovemacs.com/9226559.html



I've tried all different wiring configurations that are possible as far as I can see, all using a 5v to 3.3v converter, as I think these are both 3.3v parts. I've been attempting to get them recognized as USB devices, but no matter what config I've tried, nothing has ever appeared in Sys Info under USB devices. They use a proprietary plug on the G5 logic board but I was hoping it was tied into USB like the Infrared Sensor and A1181 Bluetooth Modules are.

Am I chasing a red herring here? Had anyone tried this with any success?


Interested to know.

Regards,
Ersterhernd
 
Never seen anyone trying this but might be interesting.
Does the IC / sensor have any text on it?

/hhra
 
Yep, heres a close-up of both sensors. The Media Bay Sensor is on the bottom. Had to tape them down to get a decent shot together.


screenshot46g.jpg



The 1893-A doesn't have a proper receptacle for a plug, so I had to directly input male leads into the header. Coded as per usual, they are red from the 3.3V power, black to ground and the 2 greens are to the D+ and D- on the USB header.

The 1890-A has a proper plug that I used. There is a little 'V' on the first (topmost) wire that I think the 3.3V power is supposed to go to.

As stated in the first post, I've tried all different combo's I can think of, not to any success. Nothing ever shows up in Sys Info. Note that these are both five-pin inputs that I've only got four wires to work with, so there's a fair number of possibilities.


Ersterhernd
 
This is a diagram that I stumbled across in the G5 Service Source guide. It shows the pinouts of the Media Bay Sensor, of which I only have the five-pin part, not the other two ends (7 and 4 pins respectively).

ambientsensorpinout.jpg


From what I gather, pins 2 goes to both the D+ or D- on a USB header, while pin 3 is unused. I think that this config is handled on the Media Bay PCB itself, and both the 2 & 3 connector slots should have a wire going in.

But again, who knows?


Ersterhernd
 
Hi

The top one reads that it is an DS1631. Going here http://www.maximintegrated.com/datasheet/index.mvp/id/3241
it also says that it is a temperature sensor.
If you read in the description the it says about the interface that: "Communication with the DS1631/DS1631A/DS1731 is achieved through a 2-wire serial interface," and further down it tells that it is "2-Wire/I2C/SMBus"
So no USB here as far as I can tell.

The other one (7752) I have not been able to identify yet.

/hhr
 
Thx hhra! I think we're getting somewhere now. The DQ77KB has two System Management Bus pins on the Custom Solutions Header. As you stated, one or perhaps both of these chips use SMB to communicate. The link below shows the SMB as commonly used for temp sensors.

http://en.wikipedia.org/wiki/System_Management_Bus

I think this could be the ticket to success. The CLK and DAT pins may work in the CS Header.

Will try it tonight when I get some time.


Cheers!
 
Tried the SMBus connections to no avail. Maybe this was proprietary technology built for the G5 logic board, who knows. Perhaps a software issue, too.

Oh well, was fun to try...



Ersterhernd
 
Sorry to hear you didn't made it work.
Maybe the modules are broken. Do you have possibility to verify if they are still Ok, in a Mac?

/hhr
 
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