{"id":752,"date":"2021-04-03T23:28:35","date_gmt":"2021-04-03T21:28:35","guid":{"rendered":"https:\/\/johann.langhofer.net\/?p=752"},"modified":"2021-04-03T23:28:35","modified_gmt":"2021-04-03T21:28:35","slug":"simple-smart-meter-ssm-using-rapberry-pi-and-esp32","status":"publish","type":"post","link":"https:\/\/langhofer.org\/?p=752","title":{"rendered":"Simple Smart Meter (SSM) using Rapberry Pi and ESP32"},"content":{"rendered":"

Having some troubles to recover a “Volksz\u00e4hler” system (server doesn’t exists any more), I decided to build my own Smart Meter system,\u00a0 user friendly, small footprint and simple to maintenance.<\/p>\n

The concept:<\/strong> S0 Impulses are counted via interrupt on a microcontroller (ESP32) and sent to a Web-server running on a Rasperry Pi. Every time, after 60 seconds, three counter values (for each phase of the power lines) are written into a\u00a0Round Robin Database (RRD) file. The graph function of RRDtool is used to present this data to a human viewer via Web-Browser.<\/p>\n

\"\"<\/p>\n

The hardware configuration: <\/strong>ESP32 ->(WLAN)->RPI2<\/p>\n

Software requirements (RPI):<\/strong> apache2, RRDtool, php7.3, php7.3-gd<\/p>\n\n\n

Skipping the microcontroller part (data is sent with a simple http-request http:\/\/<address-of-rpi>\/s0.php?data=<counter1>:<counter2>:<counter3><\/em>) here are the steps and the software parts of the smart meter:<\/p>\n\n\n

<\/p>\n\n\n

STEP 1:<\/strong> Defining the database (RRD):<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

Each minute the power line counter values are written into the database, Format: ‘R:S:T’
There are three archives in this database: one for the original data (minutes) holding the values for 10 days, one for reduced hour-values holding 18 months, and one for reduced daily-values holding 10 years.<\/p>\n\n\n

Step 2<\/strong>: Script to permanently update the database:<\/p>\n\n\n\n\n\n\n\n

\"\"<\/figure>\n\n\n\n

Step 3<\/strong>: Script to visualize the data: Call this script with three optional query parameters: start, end, step. start<\/strong>: point where to begin viewing data i.e -1d -2M -4h, default 4h (4 hours). end<\/strong>: point where to stop viewing data (default now). step<\/strong>: resolution in seconds (default 60). Example: http:\/\/<rpi-address>\/data.php?start=-2d&end=-1d<\/em><\/p>\n\n\n\n

\"\"<\/figure>\n","protected":false},"excerpt":{"rendered":"

Having some troubles to recover a “Volksz\u00e4hler” system (server doesn’t exists any more), I decided to build my own Smart Meter system,\u00a0 user friendly, small footprint and simple to maintenance. The concept: S0 Impulses are counted via interrupt on a microcontroller (ESP32) and sent to a Web-server running on a Rasperry Pi. Every time, after …<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[19,50,56,57,59,71],"class_list":["post-752","post","type-post","status-publish","format-standard","hentry","category-allgemein","tag-esp32","tag-raspbarry-pi","tag-rpi2","tag-rrdtool","tag-smart-meter","tag-volkszahler"],"_links":{"self":[{"href":"https:\/\/langhofer.org\/index.php?rest_route=\/wp\/v2\/posts\/752","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/langhofer.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/langhofer.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/langhofer.org\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/langhofer.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=752"}],"version-history":[{"count":0,"href":"https:\/\/langhofer.org\/index.php?rest_route=\/wp\/v2\/posts\/752\/revisions"}],"wp:attachment":[{"href":"https:\/\/langhofer.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=752"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/langhofer.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=752"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/langhofer.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=752"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}