{"id":484,"date":"2011-04-19T15:59:19","date_gmt":"2011-04-19T14:59:19","guid":{"rendered":"http:\/\/www.netquote.it\/nqmain\/?p=484"},"modified":"2020-01-01T21:29:49","modified_gmt":"2020-01-01T20:29:49","slug":"arduino-nano-v3-internal-temperature-sensor","status":"publish","type":"post","link":"https:\/\/www.netquote.it\/nqmain\/2011\/04\/arduino-nano-v3-internal-temperature-sensor\/","title":{"rendered":"Arduino Nano v3 internal temperature sensor"},"content":{"rendered":"<p>Calibration data:<br \/>\n<a href=\"http:\/\/www.netquote.it\/nqmain\/2011\/04\/arduino-nano-v3-internal-temperature-sensor\/termo_calibration\/\" rel=\"attachment wp-att-498\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-498\" title=\"termo_calibration\" src=\"http:\/\/www.netquote.it\/nqmain\/wp-content\/uploads\/termo_calibration.jpg\" alt=\"\" width=\"681\" height=\"104\" srcset=\"https:\/\/www.netquote.it\/nqmain\/wp-content\/uploads\/termo_calibration.jpg 681w, https:\/\/www.netquote.it\/nqmain\/wp-content\/uploads\/termo_calibration-150x22.jpg 150w, https:\/\/www.netquote.it\/nqmain\/wp-content\/uploads\/termo_calibration-300x45.jpg 300w\" sizes=\"auto, (max-width: 681px) 100vw, 681px\" \/><\/a><br \/>\n<a href=\"http:\/\/www.netquote.it\/nqmain\/wp-content\/uploads\/Atmega328P_temp_calibration.xls\">Download data &amp; formulas in excel.<\/a><br \/>\nAtmega documentation says:<br \/>\n<code>The voltage sensitivity is approximately 1 mV\/\u00b0C and the accuracy of the temperature measurement is +\/- 10\u00b0C.<\/code><br \/>\nMeasured temperature is a sum of ambient temperature and chip&#8217;s TDP.<\/p>\n<p>In fact it rises up for few minutes after the chip is powered and may change in base of load.<\/p>\n<pre><pre class=\"brush: cpp; title: ; notranslate\" title=\"\">\n\/\/ Read Atmega328P internal temperature sensor \/\/\nlong read_temp()\n{\n  \/\/ Read temperature sensor against 1.1V reference\n  ADMUX = _BV(REFS1) | _BV(REFS0) | _BV(MUX3);\n  \/\/ Start AD conversion\n  ADCSRA |= _BV(ADEN) | _BV(ADSC);\n  \/\/ Detect end-of-conversion\n  while (bit_is_set(ADCSRA,ADSC));\n  \/\/ return raw data\n  return ADCL | (ADCH &lt;&lt; 8);\n}\n\n\/\/ Convert raw temperature data to \u00b0C\ndouble conv_temp(long raw_temp)\n{\n  \/\/ f(x) = (raw - offset) \/ coeff\n  return((raw_temp - 324.31) \/ 1.22);\n}\n\nvoid setup()\n{\n  Serial.begin(115200);\n}\n\nvoid loop()\n{\n  Serial.println(conv_temp(read_temp()), 1);\n  delay(500);\n}\n<\/pre>\n<p>Datasheet Atmega 328P &#8211; <a href=\"https:\/\/www.microchip.com\/wwwproducts\/en\/ATmega328p\">https:\/\/www.microchip.com\/wwwproducts\/en\/ATmega328p<\/a><\/p>\n<p>It is a curious fact that putting chips in the freezer, after a few minutes when the temperature drops below zero, the chip stops working.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Calibration data: Download data &amp; formulas in excel. Atmega documentation says: The voltage sensitivity is approximately 1 mV\/\u00b0C and the<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[11,6,9],"tags":[],"class_list":["post-484","post","type-post","status-publish","format-standard","hentry","category-arduino","category-c","category-electronics"],"_links":{"self":[{"href":"https:\/\/www.netquote.it\/nqmain\/wp-json\/wp\/v2\/posts\/484","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.netquote.it\/nqmain\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.netquote.it\/nqmain\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.netquote.it\/nqmain\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.netquote.it\/nqmain\/wp-json\/wp\/v2\/comments?post=484"}],"version-history":[{"count":35,"href":"https:\/\/www.netquote.it\/nqmain\/wp-json\/wp\/v2\/posts\/484\/revisions"}],"predecessor-version":[{"id":1025,"href":"https:\/\/www.netquote.it\/nqmain\/wp-json\/wp\/v2\/posts\/484\/revisions\/1025"}],"wp:attachment":[{"href":"https:\/\/www.netquote.it\/nqmain\/wp-json\/wp\/v2\/media?parent=484"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.netquote.it\/nqmain\/wp-json\/wp\/v2\/categories?post=484"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.netquote.it\/nqmain\/wp-json\/wp\/v2\/tags?post=484"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}