BS1USB Board with DS1620 Digital Thermometer

VonSzarvas

Hi all,

In the document for the DS1620 (www.parallax.com/dl/docs/prod/appkit/ds1620thermometer.pdf), it shows that 3 I/O pins are needed, and later mentions the BS1-IC giving plenty of program tips.

That all looks manageable! But my 3 questions are (before I order the relevant parts)....

1. Will the DS1620 work with the BS1USB?

2. As the BS1USB has 8 I/O's, and the DS1620 needs 3 I/O's, can I therefore add 2 DS1620 sensors to 1 BS1USB Board? (Leaving 2 spare digital I/O's, should I need to sense 2 switches or switch 2 leds off/on etc..!)

3. Is there a maximum recommended cable length between the bs1usb and the ds1620 sensors.. I am thinking of up to 10m...

... I think I have made an assumption that the usb board can power 2 ds1620's..... will need to check the specs...

Background: My idea is to have the device stream the temperature readings to a connected PC. Sampling speed is not critical - once every second would be cool, but even once a minute would be fine. (So once every X period, the board would perhaps send "T1,25,42" to the pc, where T1 means temp module 1, and the 2 temps follow.)



Thanks for your advice!
Max.

Bean

Here is exactly what you are looking for http://www.parallax.com/dl/docs/cols/nv/vol7/col/NV131.pdf

Bean.

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VonSzarvas

Thanks Bean, I have bookmarked the Nuts&Volts for future searching.

That article (as you say) covers exactly what I was thinking.

I will experiment with 2 sensors and report back if the bs1usb can handle it!!

Chris Savage

Maxwin,

Also note the DS1620 is an SPI device. It can share its clock and data lines so 2 devices would take 4 I/O pins, and 3 devices would take 5 I/O pins, etc. Take care.

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Chris Savage
Parallax Tech Support

VonSzarvas

That is good information. I will try ordering some extras and really try it...

I am being lazy not looking as I type and think of this, but is there an SPI ADC chip/circuit somewhere that would plug so nicely as the ds1620 does?

Chris Savage

ADC0831, which can be found at the following page...Take Care.

http://www.parallax.com/detail.asp?product_id=ADC0831

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Chris Savage
Parallax Tech Support