Thanks for your prompt reply; So I'm going to pretend i did NOT swap ADD0 and ALT pins on the sensor.
After much, pain - (I broke my whole dev environment updating sdk and my low cost android cellphone do not seem to like the latest adb, reinstall everything from scratch - while I was finalizing the fritzing pictures for this post I had an horrible doubt, searched for multiple internet sources and I wired my tmp102 the wrong way : after grounding pin ADD0 instead of pin ALT all readings seem to be more in my acceptable range. 0.5°c <https://lh6.googleusercontent.com/-yeVKsNe18VM/VL_4xpRM7iI/AAAAAAAAAAM/qEFU_AR_SY0/s1600/readings_in_debug.jpg> <https://lh6.googleusercontent.com/-6r_UkudIXbA/VL_43ea5tnI/AAAAAAAAAAU/ExaaGaPmtfo/s1600/schematics.jpg> On Wednesday, January 21, 2015 at 7:05:44 AM UTC+1, Ytai wrote: > > > 1. The 3.3V rail on the IOIO should be very stable, I don't think this > is a likely problem. > 2. Can you share your electrical diagram as well as a minimal app with > which you're seeing the problem? > 3. Is it possible that for some reason the sensor is actually indeed > warmer than the reference with this setup? > > Since you're actually able to talk to the sensor, I find it hard to > imagine what sort of conditions may cause reading an incorrect temperature. > I've used this sensor pretty extensively in the past (both with and without > the IOIO) and tend to trust it a lot. > > On Tue, Jan 20, 2015 at 1:07 AM, <[email protected] <javascript:>> wrote: > >> Hello, >> >> I'm having a hard time with TMP102 sensor. >> >> Thanks to Ytai code snippet conversion and register reading is correct. >> >> What is incorrect *seems *to be the sensor itself. >> >> Analog thermometer is used as a reference, and I get errors from 6° to >> 1,5° in excess on the tmp102, In "ambient temperature" area (from 10°c to >> 25°c) >> I tested with another TMP102 sensor (also purchased from sparkfun, thus >> with a different pin layout), the same weird behavior. >> The error seems to be changing over time (As if the sensor needed 30+ >> minutes to stabilize) but never disappears. At the time being I have set a >> "-1.5" correction. >> >> The sensor is read every 5 seconds. >> >> >> I tested the same tmp102 sensor on a arduino board (with a very fast >> loop), and the readings are correct (well, within 0.2°c of the reference >> thermometer). >> >> >> >> I wonder If the arduino fast loop helps the sensor reaching operational >> conditions (let's call that warming up ?), and the 5 sec loop on the >> android does not allow tmp102 to work properly. Or maybe my ioio power >> supply is interfering (8 volts, 1000mah) with the tmp102 (sensor VCC is >> plugged to 3v on the board itself). >> >> >> I'm working on a thermostat, temperature reading reliability is rather >> important. >> >> >> I ordered an MCP9808 sensor to compare readings. >> >> Any idea, testing pattern or any "reliable" sensor to recommend ? >> >> >> (BTW Ytai : Many, many thanks for your *great* work. ) >> -- >> You received this message because you are subscribed to the Google Groups >> "ioio-users" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected] <javascript:>. >> To post to this group, send email to [email protected] >> <javascript:>. >> Visit this group at http://groups.google.com/group/ioio-users. >> For more options, visit https://groups.google.com/d/optout. >> > > -- You received this message because you are subscribed to the Google Groups "ioio-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/ioio-users. For more options, visit https://groups.google.com/d/optout.
