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richhbd
Joined: 03 Feb 2006 Posts: 52
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Posted: Tue Nov 21, 2006 3:21 pm Post subject: Faster temperature measurement alternatives to DS1820 series |
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Hey y'all,
Am building a datalogging system that needs to measure temperatures in a variety of locations, as well as a few different rotational speeds, voltages and so-forth.
Had initially settled on Dallas DS18S20 1-wire sensors for the temperature side, and everything's now up and running. However, am trying to optimise, and get the sampling rate down as low as it can be.
While the "skip ROM" 1-wire command enables all the temp sensors to be inited at once - and thus it doesn't matter whether there's one device or 100 on the bus, reading each device takes about 19.2ms, so if I poll eight sensors every sample, that's 150ms before even thinking about the other sensors I'm monitoring.
Now the obvious solution to this is to poll the DS18S20s less frequently than the other sensors - and that's what I'm going with to start with.
However, from a perfectionist point of view, I'm wondering whether some of the other obvious alternatives are quicker in operation. I've already got a TWI bus set up to service a DS1307 RTC, so switching to I2C based sensors like the DS1621 or AD7414 wouldn't be much hassle - if there's a speed benefit in doing so.
Anyone got any experience with these sensors - or, even better, got any data on their speed of operation? |
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press9761
Joined: 20 Jun 2006 Posts: 108
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Posted: Wed Nov 22, 2006 3:05 am Post subject: |
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hay man.
I've been looking at these, I haven't gotten them yet, but I'm strongly considering it. mostly because of the price (.99) each. you can use 8 at a time and (I think) they are a lot faster, however, their not in the nice TO-92 packaging. They are SOIC
http://www.standardics.nxp.com/literature/leaflets/i2c/pdf/lm75a.pdf |
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press9761
Joined: 20 Jun 2006 Posts: 108
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Posted: Wed Nov 22, 2006 3:06 am Post subject: |
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hay man.
I've been looking at these, I haven't gotten them yet, but I'm strongly considering it. mostly because of the price (.99) each. you can use 8 at a time and (I think) they are a lot faster, however, their not in the nice TO-92 packaging. They are SOIC
http://www.standardics.nxp.com/literature/leaflets/i2c/pdf/lm75a.pdf |
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