What IC's can I use to design a battery-operated temperature unit for consumer use? I'm seeking to design the kind of unit that allows one to wirelessly read outside temperature with the ubiquitous inexpensive consumer digital thermometers on the market to 0.1 degree C.
I'm not much af an electronic engineer, but give me a few months I can propably get a reasonable hang of wireless temperature measurement. Probably less to get a working arrangement. Thanks.
Richard,
Unfortunately none of our sensors can achieve ±0.1°C accuracy.
The TMP112 is our most accurate contact temperature sensor - it measures the temperature of what it is attached to. It can acheive less than ±0.5°C accuracy via calibration as described on page 16 in the data sheet.
Regards, Dan
Dan. Thanks for the suggestion. TI is probably not in the market for consumer weather -type thermometers, but concentrates it's efforts elsewhere. Well, I'm assuming that given your suggestion. It's quite amazing when you think about the resolution offered by the ubiquitous consumer weather thermometer, which is typically 0.1C. Whether these consumer thermometers are that accurate I would not know, but that is what specifications say. I probably cannot go any futher if I'm trying to meet 0.1C resolution. But, again, thanks. Rich
I wonder if I'm not understanding the difference between resolution and accuracy. TMP112: RESOLUTION is to 0.0625C, but ACCURACY to 0.5C max. So, I'm wondering by the time the temperature was being read on the receiver's digital display, whether it would be entirely possible to quote a parameter of 0.1C resolution for the thermometer.
When I look at the parameters of consumer weather thermometers, they only quote RESOLUTION. They don't mention ACCURACY. So, I don't actually know what accuracy I'm dealing with, with consumer weather thermometers.
Resolution is the internal ADC °C/LSB while accuracy is over the full temp range the "error" in the output relative to the "real" temperature of the object being measured.
Okay, I'm back on track. Looking at a fairly expensive weather station, the best possible accuracy, in the range, was quoted at +- 1C.
That should be my parameter. I assume that something like TMP112 would be in the ballpark regarding that parameter.
Just another question, before I take leave and immerse myself in the subject: What IC or IC's might you match with the TMP112, to make a type of wireless unit, to transmit the temperature data to a receiver unit? Outputting say 433Mhz. If I can study the application notes for the required IC's, I can make some much needed progress. Thanks. Rich
EDIT1: Oh, this might be what I'm looking for-ish:
http://www.ti.com/lit/ml/slyt472/slyt472.pdf
Unfortunately, I am not a wireless guy...
TI has a low energy bluetooth "Sensor Tag" solution that uses one of our other temperature sensors, but the same basic concept would apply.
Other than that I would recommend reviewing TI's Wireless Product Selection for a device that may meet you communication requirements.