{"id":31,"date":"2017-03-20T22:22:57","date_gmt":"2017-03-20T22:22:57","guid":{"rendered":"https:\/\/test.warrensoft.co.uk\/wp-test\/home-hub\/?p=31"},"modified":"2018-12-08T07:32:38","modified_gmt":"2018-12-08T07:32:38","slug":"hardware-sensors","status":"publish","type":"post","link":"https:\/\/test.warrensoft.co.uk\/wp-test\/2017\/03\/20\/hardware-sensors\/","title":{"rendered":"Hardware &#8211; Sensors"},"content":{"rendered":"<p>The majority of measurements in the production version of the home hub utilised the DHT22\/AM2302 temperature and humidity sensor.<\/p>\n<figure id=\"attachment_32\" aria-describedby=\"caption-attachment-32\" style=\"width: 140px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-32 size-full\" src=\"https:\/\/test.warrensoft.co.uk\/wp-test\/wp-content\/uploads\/2017\/03\/dht22.jpg\" alt=\"\" width=\"140\" height=\"140\" srcset=\"https:\/\/test.warrensoft.co.uk\/wp-test\/wp-content\/uploads\/2017\/03\/dht22.jpg 140w, https:\/\/test.warrensoft.co.uk\/wp-test\/wp-content\/uploads\/2017\/03\/dht22-100x100.jpg 100w\" sizes=\"auto, (max-width: 140px) 100vw, 140px\" \/><figcaption id=\"caption-attachment-32\" class=\"wp-caption-text\">DHT22\/AM2302<\/figcaption><\/figure>\n<p>The DHT22, AM2302 \u00a0or equivalent has a number of benefits:<\/p>\n<ul>\n<li>low cost<\/li>\n<li>single-wire bus connection<\/li>\n<li>interface software readily availableThe only drawback I have come across is the limitation of cable distance. In practice, even with corrective measures, the maximum distance from Pi to sensor is about 4m.<\/li>\n<\/ul>\n<figure id=\"attachment_34\" aria-describedby=\"caption-attachment-34\" style=\"width: 225px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-34 size-full\" src=\"https:\/\/test.warrensoft.co.uk\/wp-test\/wp-content\/uploads\/2017\/03\/bme280.jpg\" alt=\"\" width=\"225\" height=\"225\" srcset=\"https:\/\/test.warrensoft.co.uk\/wp-test\/wp-content\/uploads\/2017\/03\/bme280.jpg 225w, https:\/\/test.warrensoft.co.uk\/wp-test\/wp-content\/uploads\/2017\/03\/bme280-150x150.jpg 150w, https:\/\/test.warrensoft.co.uk\/wp-test\/wp-content\/uploads\/2017\/03\/bme280-100x100.jpg 100w\" sizes=\"auto, (max-width: 225px) 100vw, 225px\" \/><figcaption id=\"caption-attachment-34\" class=\"wp-caption-text\">BME280<\/figcaption><\/figure>\n<p>For this reason I have deployed the BME280 in situations where greater distances are involved. Fortunately the production version was installed in a bungalow, which permitted the majority of rooms to be reached using short cable runs from the centrally loft-mounted pi.<\/p>\n<p>Unfortunately, the BME280 sensor requires additional circuitry to connect the Pi to its I2C or SPI interface. I will cover this in a later post.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The majority of measurements in the production version of the home hub utilised the DHT22\/AM2302 temperature and humidity sensor. The DHT22, AM2302 \u00a0or equivalent has a number of benefits: low cost single-wire bus connection interface software readily availableThe only drawback I have come across is the limitation of cable distance. In practice, even with corrective &hellip; <\/p>\n<p class=\"link-more\"><a href=\"https:\/\/test.warrensoft.co.uk\/wp-test\/2017\/03\/20\/hardware-sensors\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Hardware &#8211; Sensors&#8221;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[],"class_list":["post-31","post","type-post","status-publish","format-standard","hentry","category-hub-hardware"],"_links":{"self":[{"href":"https:\/\/test.warrensoft.co.uk\/wp-test\/wp-json\/wp\/v2\/posts\/31","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/test.warrensoft.co.uk\/wp-test\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/test.warrensoft.co.uk\/wp-test\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/test.warrensoft.co.uk\/wp-test\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/test.warrensoft.co.uk\/wp-test\/wp-json\/wp\/v2\/comments?post=31"}],"version-history":[{"count":6,"href":"https:\/\/test.warrensoft.co.uk\/wp-test\/wp-json\/wp\/v2\/posts\/31\/revisions"}],"predecessor-version":[{"id":638,"href":"https:\/\/test.warrensoft.co.uk\/wp-test\/wp-json\/wp\/v2\/posts\/31\/revisions\/638"}],"wp:attachment":[{"href":"https:\/\/test.warrensoft.co.uk\/wp-test\/wp-json\/wp\/v2\/media?parent=31"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/test.warrensoft.co.uk\/wp-test\/wp-json\/wp\/v2\/categories?post=31"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/test.warrensoft.co.uk\/wp-test\/wp-json\/wp\/v2\/tags?post=31"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}