Comments on: Parts: I2C digital thermometer (TC74)

By: Tim

Tim — Sun, 27 Jun 2010 21:26:13 +0000

You could use the TMP175 instead of the TC74. You can have 15 (I think) sensors on the I2C bus. Have a look at: http://focus.ti.com/lit/ds/symlink/tmp175.pdf

I am using them with an arduino, then seem to work just fine.

Tim.

By: mowcius

mowcius — Sun, 27 Jun 2010 12:15:51 +0000

“is there any way of changing the address of the sensor? I would like to have more then one on a I2C bus.”
Nope. Unfortunately not. I think this catches a lot of people out but I can buy them in single units thankfully :)

By: Jim

Jim — Sat, 20 Mar 2010 23:41:03 +0000

is there any way of changing the address of the sensor? I would like to have more then one on a I2C bus. I can order small qualities of TC74 with address 9a but have to order 350 to get any of the other addresses.

By: n0th1n6

n0th1n6 — Mon, 05 Jan 2009 01:07:36 +0000

ds1621+ from maxim is a temp sensor with i2c interface and has better resolution than this one. Without much effort, you can easily get .5°C resolution from this ic. only downside i guess is the package

By: Scotty

Scotty — Sun, 04 Jan 2009 07:01:42 +0000

The component variety and quality of these posts is astounding. Short and sweet. I’m hoping to see some more complex devices requiring longer tutorials such as the DS28EA00 (1wire temp sensor with I/o pins) or perhaps one of the new Dallas RTC’s with 4Kbytes or more of NVRAM. What is already posted is pure gold.

By: Gman

Gman — Sun, 04 Jan 2009 00:04:08 +0000

OOOHHHH how i wish i understood what all of this mumbo jumbo meant and how to do this….i just dont know where to start when wanting to learn about this stuff… :..(

By: tantris

tantris — Sat, 03 Jan 2009 20:38:57 +0000

Nice part, and also affordable!

now, if someone could find a humidity sensor that isn’t $20 …

By: octel

octel — Sat, 03 Jan 2009 10:02:09 +0000

@colin: use a thermocouple

By: Colin

Colin — Sat, 03 Jan 2009 09:03:10 +0000

Does anyone know a good sensor in the 200-400 C range with at least 1 degree precision?

By: Andrew

Andrew — Sat, 03 Jan 2009 00:33:53 +0000

@mike y and ian lesnet,

Thanks for the description and link guys, that’s very helpful!

By: Ian Lesnet

Ian Lesnet — Fri, 02 Jan 2009 18:10:15 +0000

@andrew

Sometimes we get too creative while trying not to be repetitive. This small update should better reflect what we wanted to say:

C1 is a 0.1uF decoupling capacitor.

By: Mike Y

Mike Y — Fri, 02 Jan 2009 18:04:24 +0000

> It says “A 0.1uF capacitor (C1) decouples the chip
> from the power supply.” What does “decouples”
> mean in that sentence and why is the capacitor on
> the ground side and not the vcc side?

Looks like C1 connects to both Pin 5, which is 3.3V and to GND. ‘Decouples’ means to basically provide some power protection against RF pickup – RF will go through the cap to ground, leaving the DC clean.

An alternative word would be a ‘bypass’ capacitor, ref:
http://en.wikipedia.org/wiki/Decoupling_capacitor

I just placed a mouser order prior to seeing this neat little IC. I’ve put it on a list for next time…!

Mike Yancey
Dallas, Texas

By: Andrew

Andrew — Fri, 02 Jan 2009 17:10:57 +0000

It says “A 0.1uF capacitor (C1) decouples the chip from the power supply.” What does “decouples” mean in that sentence and why is the capacitor on the ground side and not the vcc side?

By: Ty Johnson

Ty Johnson — Fri, 02 Jan 2009 17:07:18 +0000

Cool! i can think of a lot of stuff to bolt this thing to.
cpu heatsink, inside the freezer (because no one likes hard-as-a-rock ice cream!), my modded surround amp… thanx for the write up!