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Grogster

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Joined: 31/12/2012
Location: New Zealand
Posts: 9501

Posted: 02:59pm 10 Sep 2014

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Hi all.

I am looking at these on eBay.

Output from the 6675 chip is SPI interface, and as I have never used this before, do any of you here see any issues connecting this thing to a MicroMite chip?

Can't upload the PDF, as it is bigger then the upload size limit, but HERE is a link to the page and download for the PDF.

Smoke makes things work. When the smoke gets out, it stops!

Zonker

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Joined: 18/08/2012
Location: United States
Posts: 767

Posted: 04:16pm 10 Sep 2014

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Hey Grogs..

I have used the MAX31855 part for the EIS system and it seems to work well.. I spun up a chunk of spaghetti code for the color MM that displayed bar graphs and such... I want to get back on it when things settle down a bit... (right) Anyway, Maxim also makes a ready to go module that offers a way better frontend that has protection and proper termination caps, ect.. I didn't see any such things on the Ebay module... I first got a couple of the chips, and played around, they worked ok.. But, after getting the modules, I noticed way better readings, and after getting the PDF's on it, I saw the proper "front end" circuitry.. I can dig it up if you want...

jman

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Joined: 12/06/2011
Location: New Zealand
Posts: 711

Posted: 06:55pm 12 Sep 2014

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Hi

I have used the Max31855 Max31855 Datasheet

They look real similar
Here is my code for the MAX31855 not very tidy but it works

Dim byte(4)

SetPin 6, 2 'set rx pin As a digital input
SetPin 7, 8 'set tx pin As an output
Pin(4) = 1 : SetPin 4, 8 'set clk pin high Then set it As an output
Pin(5) = 1 : SetPin 5, 8 'pin 11 will be used As the enable signal

start:

Pin(5) = 0 'assert the enable line (active low)

For I = 0 To 3
byte(I) = SPI(6, 7, 4) 'get the first byte from the slave

Next i

Pin(5) = 1

tmp = (byte(0) * 16) + (byte(1) \ 16)
tmpdec = byte(1) \ 4 And &B00000011
tmpdec = tmpdec * .25
tmp = tmp + tmpdec
tmp1 = tmp + Tmp1
Pause 100

sc = sc + 1

If sc < 10 Then
GoTo start
EndIf

Printme:
tmp = tmp1 / 10

tmp$ = Format$(tmp,"%6.1f")
? tmp$
sc = 0
tmp1 = 0

GoTo start

Regards
Jmam

Grogster

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Joined: 31/12/2012
Location: New Zealand
Posts: 9501

Posted: 07:12pm 12 Sep 2014

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Thank you - I will study your code.

I am also looking at the AD595 chip, as it outputs a voltage - 10mV/'C

The 595 can be had on eBay for about $12, but is VERY simple to get up and running, so should be as simple as reading the pin set as analog in - T=PIN(10) kind of thing.Edited by Grogster 2014-09-14

Smoke makes things work. When the smoke gets out, it stops!

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