https://www.heepy.net/index.php?action=history&feed=atom&title=Sensirion_humidity_%26_temperature_sensors 2026-05-10T17:44:42Z Revision history for this page on the wiki MediaWiki 1.35.2 https://www.heepy.net/index.php?title=Sensirion_humidity_%26_temperature_sensors&diff=1257&oldid=prev 2012-01-17T08:56:40Z

<p></p> <table class="diff diff-contentalign-left diff-editfont-monospace" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 08:56, 17 January 2012</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l8" >Line 8:</td> <td colspan="2" class="diff-lineno">Line 8:</td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>atmega8. Even with the float stuff it still fits in 8k.   </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>atmega8. Even with the float stuff it still fits in 8k.   </div></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>−</td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The manufacturer's data sheet is at  </div></td><td class='diff-marker'>+</td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The manufacturer's data sheet is <ins class="diffchange diffchange-inline">duplicated </ins>at  </div></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>http://www.sparkfun.com/datasheets/Sensors/SHT1x_datasheet.pdf</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>http://www.sparkfun.com/datasheets/Sensors/SHT1x_datasheet.pdf</div></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <!-- diff cache key wikidb:diff::1.12:old-1256:rev-1257 --> </table>

Morris https://www.heepy.net/index.php?title=Sensirion_humidity_%26_temperature_sensors&diff=1256&oldid=prev 2012-01-17T08:56:00Z

<p>Created page with &quot;Library and demo program for SHT15 temperature and humidity sensor from Sensirion. Get one on a breakout board from sparkfun.com. It&#039;s not cheap, but it seems to produce repeatab…&quot;</p> <p><b>New page</b></p><div>Library and demo program for SHT15 temperature and humidity sensor<br /> from Sensirion. Get one on a breakout board from sparkfun.com. It's<br /> not cheap, but it seems to produce repeatable and stable output. <br /> <br /> This driver doesn't depend on any hardware support except GPIOs,<br /> so it should run on any AVR. You might need to provide different<br /> uart routines to get serial output from the demo program on say an <br /> atmega8. Even with the float stuff it still fits in 8k. <br /> <br /> The manufacturer's data sheet is at <br /> http://www.sparkfun.com/datasheets/Sensors/SHT1x_datasheet.pdf<br /> <br /> It speaks a two wire protocol that's almost like i2c but just slightly<br /> gratuitously different, so you have to bitbang it. Its data line is open drain,<br /> so in theory it might be able to coexist with an actual i2c<br /> bus on the same wires, but when i tried it it seemed to hang <br /> the bus in its default power-on state. <br /> <br /> It has two resolution modes, 12 bit humidity + 14 bit temperature,<br /> and 8 bit humidity + 12 bit temperature, of which I've only<br /> implemented the higher resolution one. To use the other, you<br /> write 0x01 to the status register and then use a different <br /> polynomial (detailed in the datasheet) to convert the readout<br /> to real floating point values. If you want more accuracy, read<br /> temperature first, and then pass the temperature reading to <br /> sht_humidity_comp() which adds temperature compensation to the<br /> basic humidity reading. <br /> <br /> It also has a low-voltage warning bit and a builtin electric<br /> heater which you can apparently use to test it - turning it on<br /> draws a few mA and causes the temp reading to go up and the <br /> humidity reading to go down, as expected. Don't leave it on permanently. <br /> <br /> eric volpe http://heepy.net 4/21/2010</div>

Morris