{"id":563,"date":"2020-04-08T09:30:35","date_gmt":"2020-04-08T09:30:35","guid":{"rendered":"http:\/\/www.chatrail.com\/?page_id=563"},"modified":"2020-04-23T08:23:43","modified_gmt":"2020-04-23T08:23:43","slug":"dcc-dmx","status":"publish","type":"page","link":"http:\/\/www.chatrail.com\/index.php\/dcc-dmx\/","title":{"rendered":"DCC & DMX CONTROL"},"content":{"rendered":"\n

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More of a hobby project that was originally written 20 years ago in C using MPLAB and more recently updated to C++. The original code (a state machine driven from hardware interrupts) ran on a PIC16F driving a full H-Bridge to realise an NMRA compatible DCC (Digital Command Control) locomotive decoder. <\/p><\/p>\n\n\n\n

A few years later I got involved with an amateur dramatics group where I helped them update their lighting to DMX512 and saw the opportunity to master another single master multi slave protocol.<\/p><\/p>\n\n\n\n

Stage lights and model trains don’t initially look like easy partners but they are both primarily receive, state-driven serial protocols and it was fun to see if I could use class abstraction to have a single code base driving both projects spanning three protocols (NMRA DCC, Hornby Zero-1 and DMX 512<\/em>). Was it overkill? Possibly, but what are hobbies for if not to indulge in an idea or two.<\/p><\/p>\n\n\n\n

TO DO: Add state diagram and hardware block schematics. <\/em><\/p>\n\n\n\n

In another little railway project, I used a couple of 16 channel relay boards and a chain of half a dozen 74595s all linked to an Arduino Nano to automate a display layout. Two of the 595’s drive reed switches with one end connected via steering diodes to a GPIO having a mapped interrupt handler to make a 16 column, single row ‘keyboard matrix’. ‘Inputs from outputs’, neat! To get the scanning performance I needed the SPI hardware built into the AVR chip drives the 595 chain, although not a true SPI application it works a dream. The AVR only has one SPI interface so a 2 line LCD was linked using I2C to give user feedback.<\/p><\/p>\n\n\n\n

TO DO: include a photo of the controller.<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

More of a hobby project that was originally written 20 years ago in C using MPLAB and more recently updated to C++. The original code (a state machine driven from hardware interrupts) ran on a PIC16F driving a full H-Bridge to realise an NMRA compatible DCC (Digital Command Control) locomotive decoder. A few years later […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":[],"_links":{"self":[{"href":"http:\/\/www.chatrail.com\/index.php\/wp-json\/wp\/v2\/pages\/563"}],"collection":[{"href":"http:\/\/www.chatrail.com\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"http:\/\/www.chatrail.com\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"http:\/\/www.chatrail.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.chatrail.com\/index.php\/wp-json\/wp\/v2\/comments?post=563"}],"version-history":[{"count":22,"href":"http:\/\/www.chatrail.com\/index.php\/wp-json\/wp\/v2\/pages\/563\/revisions"}],"predecessor-version":[{"id":1086,"href":"http:\/\/www.chatrail.com\/index.php\/wp-json\/wp\/v2\/pages\/563\/revisions\/1086"}],"wp:attachment":[{"href":"http:\/\/www.chatrail.com\/index.php\/wp-json\/wp\/v2\/media?parent=563"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}