{"id":897,"date":"2014-06-09T15:31:42","date_gmt":"2014-06-09T22:31:42","guid":{"rendered":"https:\/\/blog.digilentinc.com\/?p=897"},"modified":"2021-06-17T08:56:23","modified_gmt":"2021-06-17T15:56:23","slug":"digital-thermometer","status":"publish","type":"post","link":"https:\/\/digilent.com\/blog\/digital-thermometer\/","title":{"rendered":"Digital Thermometer"},"content":{"rendered":"

Today I’m\u00a0going to take a look into how to\u00a0make a digital thermometer using parts\u00a0from the chipKIT™ Starter Kit<\/a>.<\/p>\n

 <\/p>\n

As Martha mentioned<\/a> back on May 19th, the chipKIT™ Starter Kit has some components that can be used in some more advanced\u00a0projects, like the negative temperature coefficient (NTC) thermistor and the seven-segment display which we can use for a digital\u00a0thermometer. \u00a0For those of you who might not know or would like a refresher, a thermistor is a type of a resistor that changes\u00a0it’s resistance in accordance with the ambient temperature. \u00a0The NTC portion in our thermistor means that as the temperature\u00a0goes up, the resistance of the thermistor goes down. \u00a0It is\u00a0then possible to measure this changing resistance by using a voltage divider circuit\u00a0and figure out the temperature.<\/p>\n

 <\/p>\n

The other component I mentioned, the seven-segment display, is\u00a0the “digital” in digital thermometer. The Starter Kit’s\u00a0particular seven-segment has four digits that we can use to display the temperature. \u00a0However, seven-segment displays\u00a0work by lighting up one (and only one) digit out of the four available at any time. \u00a0Although this seems rather counter-intuitive\u00a0for displaying the temperature, there is a nice trick\u00a0to use to circumvent this problem. \u00a0If one\u00a0cycles through\u00a0displaying each of the individual digits fast enough, our brains won’t be able to notice that only one digit is being displayed\u00a0at a time; rather, it will look like they are all displaying at the same time. Pretty convenient, isn’t it?<\/p>\n

 <\/p>\n

But back to the temperature. \u00a0One can convert the voltage drop across the thermistor into temperature by using what is called the\u00a0B-parameter equation. \u00a0However, the temperature that is reported is in the Kelvin temperature scale, which if you’re like me,\u00a0don’t have any real idea of what 300 Kelvin feels like without turning it into something more familiar, like Fahrenheit. \u00a0Luckily,\u00a0this is pretty easily done within the MPIDE\u00a0code.\u00a0So you\u00a0can now turn the temperature into Fahrenheit, Celcius, or for the really\u00a0ambitious, a temperature scale of your own invention!<\/p>\n

 <\/p>\n

Here’s a picture of the final circuit showing the cozy 68.4 \u00b0F here at Digilent.<\/p>\n

\"68.4F\"<\/a><\/p>\n

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Today I’m going to take a look into how to make a digital thermometer using parts from the chipKIT™ Starter Kit.<\/p>\n","protected":false},"author":17,"featured_media":905,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[20,4327],"tags":[104],"ppma_author":[4469],"class_list":["post-897","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-products","category-projects","tag-project-2"],"jetpack_featured_media_url":"https:\/\/digilent.com\/blog\/wp-content\/uploads\/2014\/06\/68.4F.jpg","jetpack_sharing_enabled":true,"authors":[{"term_id":4469,"user_id":17,"is_guest":0,"slug":"jamescolvin","display_name":"James Colvin","avatar_url":"https:\/\/secure.gravatar.com\/avatar\/8aa85f7d11711acc7e571e1ed26c901b614a7064a2e15e522f54d9f26792ea9e?s=96&d=mm&r=g","1":"","2":"","3":"","4":"","5":"","6":"","7":"","8":"","9":"","10":""}],"post_mailing_queue_ids":[],"_links":{"self":[{"href":"https:\/\/digilent.com\/blog\/wp-json\/wp\/v2\/posts\/897","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/digilent.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/digilent.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/digilent.com\/blog\/wp-json\/wp\/v2\/users\/17"}],"replies":[{"embeddable":true,"href":"https:\/\/digilent.com\/blog\/wp-json\/wp\/v2\/comments?post=897"}],"version-history":[{"count":0,"href":"https:\/\/digilent.com\/blog\/wp-json\/wp\/v2\/posts\/897\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/digilent.com\/blog\/wp-json\/wp\/v2\/media\/905"}],"wp:attachment":[{"href":"https:\/\/digilent.com\/blog\/wp-json\/wp\/v2\/media?parent=897"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/digilent.com\/blog\/wp-json\/wp\/v2\/categories?post=897"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/digilent.com\/blog\/wp-json\/wp\/v2\/tags?post=897"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/digilent.com\/blog\/wp-json\/wp\/v2\/ppma_author?post=897"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}