[{"data":1,"prerenderedAt":106},["ShallowReactive",2],{"article-cessna172-heading-indicator":3},{"id":4,"title":5,"body":6,"description":95,"downloads":96,"extension":97,"lastUpdated":98,"meta":99,"navigation":100,"path":101,"readingTime":102,"seo":103,"stem":104,"__hash__":105},"projectArticles\u002Fprojects\u002Fcessna172\u002Fheading-indicator.md","Heading Indicator",{"type":7,"value":8,"toc":88},"minimark",[9,14,18,22,25,66,70,81,85],[10,11,13],"h2",{"id":12},"overview","Overview",[15,16,17],"p",{},"The Heading Indicator (HI), also known as the directional gyro (DI), sits bottom-centre in the six-pack \"T\" arrangement. It shows aircraft heading on a rotating compass card against a fixed lubber line, with a heading bug used by the KAP 140 autopilot's HDG mode.",[10,19,21],{"id":20},"construction","Construction",[15,23,24],{},"Like the other six-pack instruments, this gauge is built as a self-contained module:",[26,27,28,36,42,48,54,60],"ul",{},[29,30,31,35],"li",{},[32,33,34],"strong",{},"Bezel \u002F Face Plate"," — 3D-printed bezel with a fixed lubber line marking",[29,37,38,41],{},[32,39,40],{},"Dial \u002F Needle"," — rotating compass card in place of a needle",[29,43,44,47],{},[32,45,46],{},"Internal Mechanics"," — stepper motor driving the compass card; a second stepper (or a knob with encoder feedback) drives the heading bug for the autopilot",[29,49,50,53],{},[32,51,52],{},"Back Housing"," — 3D-printed enclosure mounting to the MIP frame's instrument cutout",[29,55,56,59],{},[32,57,58],{},"PCB & Controller"," — ESP32 driving the compass card and heading bug mechanisms",[29,61,62,65],{},[32,63,64],{},"Lighting"," — backlighting for night\u002FIFR panel illumination",[10,67,69],{"id":68},"x-plane-integration","X-Plane Integration",[71,72,78],"pre",{"className":73,"code":75,"language":76,"meta":77},[74],"language-text","sim\u002Fcockpit2\u002Fgauges\u002Findicators\u002Fheading_electric_deg_mag_pilot\n\n# Heading bug (shared with KAP 140 autopilot)\nsim\u002Fcockpit2\u002Fautopilot\u002Fheading_dial_deg_mag_pilot\n","text","",[79,80,75],"code",{"__ignoreMap":77},[10,82,84],{"id":83},"status","Status",[15,86,87],{},"Planning — design not yet started.",{"title":77,"searchDepth":89,"depth":89,"links":90},2,[91,92,93,94],{"id":12,"depth":89,"text":13},{"id":20,"depth":89,"text":21},{"id":68,"depth":89,"text":69},{"id":83,"depth":89,"text":84},"Physical Heading Indicator (directional gyro) for the Cessna 172SP Six-Pack panel — bezel, compass card mechanism, heading bug, and X-Plane dataref mapping.",null,"md","2026-06",{},true,"\u002Fprojects\u002Fcessna172\u002Fheading-indicator",4,{"title":5,"description":95},"projects\u002Fcessna172\u002Fheading-indicator","LthHsIAr-BEsLkBiWulfkCnv5IKqlSEZHrHjuFrgMQI",1781294861429]