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Forum Index : Microcontroller and PC projects : Using a MAX6675 SPI Thermocouple amp...
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Grogster Admin Group  Joined: 31/12/2012 Location: New ZealandPosts: 9066 |
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! |
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Zonker Guru  Joined: 18/08/2012 Location: United StatesPosts: 761 |
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... |
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jman Guru Joined: 12/06/2011 Location: New ZealandPosts: 711 |
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 |
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| Grogster Admin Group Joined: 31/12/2012 Location: New ZealandPosts: 9066 |
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. Smoke makes things work. When the smoke gets out, it stops! |
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