{"id":72,"date":"2014-09-28T23:11:23","date_gmt":"2014-09-28T23:11:23","guid":{"rendered":"http:\/\/yehudaheraldry.com\/blog\/?p=72"},"modified":"2014-09-30T14:06:06","modified_gmt":"2014-09-30T14:06:06","slug":"digital-rapier-part-1-construction","status":"publish","type":"post","link":"http:\/\/yehudaheraldry.com\/blog\/digital-rapier-part-1-construction\/","title":{"rendered":"Digital Rapier &#8211; Part 1 (Construction)"},"content":{"rendered":"<p><strong>Background<\/strong>:<\/p>\n<p>In SCA rapier combat, determining how hard a thrust hits has been an outstanding question for some time.\u00a0 With the recent discussions of rapier pikes and reduced armor standards, this has become more important.\u00a0 Various mechanical systems have been built to attempt to measure this information (known as The Machine).\u00a0\u00a0 This project is my attempt to gather the data electronically.<\/p>\n<p><strong>Hardware Basics:<\/strong><\/p>\n<p>The Digital Rapier uses three main components.\u00a0 A Force Sensitive Resistor (FSR) is mounted on a sword blade to measure the force of an impact:<\/p>\n<div style=\"width: 252px\" class=\"wp-caption alignnone\"><a href=\"https:\/\/www.sparkfun.com\/products\/8685\"><img loading=\"lazy\" decoding=\"async\" class=\"\" src=\"https:\/\/cdn.sparkfun.com\/\/assets\/parts\/1\/8\/4\/6\/08685-03-L.jpg\" alt=\"\" width=\"242\" height=\"242\" \/><\/a><p class=\"wp-caption-text\">Force Sensitive Resistor from Sparkfun<\/p><\/div>\n<p>The FSR changes it&#8217;s resistance with load.\u00a0 It has very high (greater than 5MOhm) resistance when not loaded, and no resistance when loaded at the maximum (about 100lbs for this model).<\/p>\n<p>An Arduino Uno<\/p>\n<div style=\"width: 284px\" class=\"wp-caption alignnone\"><a href=\"http:\/\/arduino.cc\/en\/Main\/ArduinoBoardUno\"><img loading=\"lazy\" decoding=\"async\" class=\"\" src=\"http:\/\/arduino.cc\/en\/uploads\/Main\/ArduinoUno_R3_Front_450px.jpg\" alt=\"Arduino Uno\" width=\"274\" height=\"180\" \/><\/a><p class=\"wp-caption-text\">Arduino Uno<\/p><\/div>\n<p>is used to measure the resistance of the FSR using its on-board Analog-Digital Converter (ADC) and store the data.<\/p>\n<p>An AdaFruit SD Shield<\/p>\n<div style=\"width: 267px\" class=\"wp-caption alignnone\"><a href=\"http:\/\/www.adafruit.com\/products\/1141\"><img loading=\"lazy\" decoding=\"async\" class=\"\" src=\"http:\/\/www.adafruit.com\/images\/970x728\/1141-00.jpg\" alt=\"Adafruit SD Shield\" width=\"257\" height=\"193\" \/><\/a><p class=\"wp-caption-text\">Adafruit SD Shield<\/p><\/div>\n<p>is used to record the data onto an SD card and provides prototyping space to assemble the simple circuit.<\/p>\n<p>This build guide assumes a basic familiarity with electronics and Arduino.\u00a0 Please ask questions in the comments if you aren&#8217;t able to follow my directions.<\/p>\n<p><strong>Schematics:<\/strong><\/p>\n<p><a href=\"http:\/\/yehudaheraldry.com\/blog\/wp-content\/uploads\/2014\/09\/schematic1.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-69\" src=\"http:\/\/yehudaheraldry.com\/blog\/wp-content\/uploads\/2014\/09\/schematic1-300x174.png\" alt=\"schematic1\" width=\"300\" height=\"174\" srcset=\"http:\/\/yehudaheraldry.com\/blog\/wp-content\/uploads\/2014\/09\/schematic1-300x174.png 300w, http:\/\/yehudaheraldry.com\/blog\/wp-content\/uploads\/2014\/09\/schematic1-1024x594.png 1024w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n<p>LED1 is green, LED2 is red.\u00a0 S1 is the start button, S2 is the stop button.<\/p>\n<p><strong>Bill of materials<\/strong> (I purchased everything except the Shield from SparkFun or had it on the bench.\u00a0 Feel free to source it elsewhere):<\/p>\n<ul>\n<li><a href=\"https:\/\/www.sparkfun.com\/products\/11021\">Arduino Uno<\/a> &#8211; Sparkfun, Etc. &#8211; $24.95<\/li>\n<li><a href=\"http:\/\/www.adafruit.com\/products\/1141\">Adafruit Datalogging Shield<\/a> &#8211; Adafruit &#8211; $19.95<\/li>\n<li><a href=\"https:\/\/www.sparkfun.com\/products\/8685\">Flexiforce FSR<\/a> &#8211; Sparkfun &#8211; $19.95<\/li>\n<li><a href=\"https:\/\/www.sparkfun.com\/products\/8377\">4x 330 Ohm Resistor<\/a> &#8211; Sparkfun, RadioShack, Etc. &#8211; $.25 each or less in bulk<\/li>\n<li><a href=\"https:\/\/www.sparkfun.com\/products\/11853\">1 MegaOhm Resistor<\/a> &#8211; Sparkfun, RadioShack, Etc. &#8211; $.15 each or less in bulk<\/li>\n<li>2x <a href=\"https:\/\/www.sparkfun.com\/products\/11996\">Momentary push-buttons<\/a> &#8211; Sparkfun, RadioShack, Etc. &#8211; $.95 each<\/li>\n<li><a href=\"https:\/\/www.sparkfun.com\/products\/9808\">On-off switch<\/a> &#8211; Sparkfun, RadioShack, Etc. &#8211; $1.95<\/li>\n<li>2x <a href=\"https:\/\/www.sparkfun.com\/products\/11840\">LED Holder<\/a> &#8211; Sparkfun &#8211; $.50 each<\/li>\n<li><a href=\"https:\/\/www.sparkfun.com\/products\/9590\">Red LED<\/a> &#8211; Sparkfun, RadioShack, Etc. &#8211; $.35 or less in bulk<\/li>\n<li><a href=\"https:\/\/www.sparkfun.com\/products\/9592\">Green LED<\/a> &#8211; Sparkfun, RadioShack, Etc. &#8211; $.35 or less in bulk<\/li>\n<li><a href=\"https:\/\/www.sparkfun.com\/products\/10785\">Panel-mounted DC barrel jack<\/a> (for connecting sensor) &#8211; Sparkfun, RadioShack, Etc. &#8211; $2.95<\/li>\n<li>2x <a href=\"https:\/\/www.sparkfun.com\/products\/11476\">DC barrel jack Plug\u00a0<\/a> (for connecting sensor) &#8211; Sparkfun, RadioShack, Etc. &#8211; $.95 each<\/li>\n<li><a href=\"http:\/\/www.radioshack.com\/product\/index.jsp?productId=2102490\">Size M coaxial Power Plug<\/a> (for connecting sensor) &#8211; RadioShack, Sparkfun, Etc. &#8211; $3.49<\/li>\n<li><a href=\"https:\/\/www.sparkfun.com\/products\/10287\">DC barrel jack adapter<\/a> (for connecting power to Arduino, or use one as above) &#8211; Sparkfun &#8211; $2.95<\/li>\n<li><a href=\"https:\/\/www.sparkfun.com\/products\/91\">9V Snap connector<\/a> (for connecting power to Arduino) &#8211; Sparkfun &#8211; $1.25<\/li>\n<li><a href=\"https:\/\/www.sparkfun.com\/products\/8601\">Enclosure <\/a>(any will do, I had this one on the shelf) &#8211; Sparkfun, RadioShack, recycle something &#8211; $9.95<\/li>\n<li>Wire<\/li>\n<\/ul>\n<p>Total cost to build this way &#8211; $94.04\u00a0 This does not include the cost of the SD Card.\u00a0 You probably already have one, but be sure it&#8217;s a quality brand-name card, some of the cheap ones don&#8217;t work well.\u00a0 I used a <a href=\"http:\/\/www.amazon.com\/gp\/product\/B007JRB0RE\/ref=oh_aui_detailpage_o06_s00?ie=UTF8&amp;psc=1\">SanDisk 32GB Class 4 card <\/a>which cost me $18.95<\/p>\n<p>Money can be saved by finding a cheaper enclosure and some of the other minor components.\u00a0 I am planning on developing Version 2 of the hardware which will use an <a href=\"https:\/\/www.sparkfun.com\/products\/11114\">Arduino Pro Mini<\/a>\u00a0 and a <a href=\"http:\/\/www.adafruit.com\/products\/254\">MicroSD breakout board<\/a> which should save about $25 and result in a smaller, less power-hungry system.<\/p>\n<p><strong>Powering the Arduino:<\/strong><\/p>\n<p>The Arduino Uno requires an external power source.\u00a0 It gets power from either a USB connection or through a DC barrel jack.\u00a0 Through the jack the supply needs to be greater than 7V and no more than 12V.\u00a0 A 9V battery does well.\u00a0 I used a snap connector as above, snipping off the molex connector and attaching to the barrel jack adapter.\u00a0 There are <a href=\"https:\/\/www.sparkfun.com\/products\/9518\">versions <\/a>of the 9V snap connector with a barrel plug installed, but those have a longer barrel jack and it didn&#8217;t fit into my case.\u00a0 A different shaped case would allow other hookup options.<\/p>\n<p>A switch inline with the battery controls power to the whole system.\u00a0 Any sort of on-off switch will work, I used the round one listed above as it&#8217;s easier to drill a round hole in the case than file out a square one.<\/p>\n<p><strong>The SD Shield<\/strong><\/p>\n<p>In Arduino-speak, a shield is a board that mounts on top of an Arduino, connecting to all the pins.\u00a0 The SD board from Adafruit comes either as a kit, or fully assembled.\u00a0 Even in the fully assembled version, you need to solder on the pins.\u00a0 (Soldering hint &#8211; push the pins into the Arduino first, put the board on top, and solder.\u00a0 This ensures good alignment.)<\/p>\n<p><strong>Assembling the Circuit<\/strong><\/p>\n<p>The SD shield has a small prototyping area where I assembled the rest of the circuit, mostly the connections and the resistors:<\/p>\n<div id=\"attachment_67\" style=\"width: 235px\" class=\"wp-caption alignnone\"><a href=\"http:\/\/yehudaheraldry.com\/blog\/wp-content\/uploads\/2014\/09\/IMG_0772.jpg\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-67\" class=\"size-medium wp-image-67\" src=\"http:\/\/yehudaheraldry.com\/blog\/wp-content\/uploads\/2014\/09\/IMG_0772-225x300.jpg\" alt=\"Fully assembled board\" width=\"225\" height=\"300\" srcset=\"http:\/\/yehudaheraldry.com\/blog\/wp-content\/uploads\/2014\/09\/IMG_0772-225x300.jpg 225w, http:\/\/yehudaheraldry.com\/blog\/wp-content\/uploads\/2014\/09\/IMG_0772-768x1024.jpg 768w\" sizes=\"auto, (max-width: 225px) 100vw, 225px\" \/><\/a><p id=\"caption-attachment-67\" class=\"wp-caption-text\">Fully assembled board<\/p><\/div>\n<p>The connections are just made by bridging with solder.\u00a0 I removed the SD card while soldering.\u00a0 Use stranded wire,\u00a0 20-24 gauge, for the hookups to the off-board components.\u00a0 On-board, using solid wire is fine.<\/p>\n<p>I mounted the LEDs (in their holders), switches, and panel mount jack by drilling holes in the enclosure and installing through the openings.\u00a0 Some fiddling was required to make everything fit well.<\/p>\n<div id=\"attachment_66\" style=\"width: 235px\" class=\"wp-caption alignnone\"><a href=\"http:\/\/yehudaheraldry.com\/blog\/wp-content\/uploads\/2014\/09\/IMG_0771.jpg\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-66\" class=\"size-medium wp-image-66\" src=\"http:\/\/yehudaheraldry.com\/blog\/wp-content\/uploads\/2014\/09\/IMG_0771-225x300.jpg\" alt=\"Case and board\" width=\"225\" height=\"300\" srcset=\"http:\/\/yehudaheraldry.com\/blog\/wp-content\/uploads\/2014\/09\/IMG_0771-225x300.jpg 225w, http:\/\/yehudaheraldry.com\/blog\/wp-content\/uploads\/2014\/09\/IMG_0771-768x1024.jpg 768w\" sizes=\"auto, (max-width: 225px) 100vw, 225px\" \/><\/a><p id=\"caption-attachment-66\" class=\"wp-caption-text\">Case and board<\/p><\/div>\n<p>Unfortunately, with this setup I have to unscrew the case to remove\/replace the SD card and battery.<\/p>\n<div id=\"attachment_68\" style=\"width: 235px\" class=\"wp-caption alignnone\"><a href=\"http:\/\/yehudaheraldry.com\/blog\/wp-content\/uploads\/2014\/09\/IMG_0773.jpg\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-68\" class=\"wp-image-68 size-medium\" src=\"http:\/\/yehudaheraldry.com\/blog\/wp-content\/uploads\/2014\/09\/IMG_0773-225x300.jpg\" alt=\"IMG_0773\" width=\"225\" height=\"300\" srcset=\"http:\/\/yehudaheraldry.com\/blog\/wp-content\/uploads\/2014\/09\/IMG_0773-225x300.jpg 225w, http:\/\/yehudaheraldry.com\/blog\/wp-content\/uploads\/2014\/09\/IMG_0773-768x1024.jpg 768w\" sizes=\"auto, (max-width: 225px) 100vw, 225px\" \/><\/a><p id=\"caption-attachment-68\" class=\"wp-caption-text\">Assembled data recorder<\/p><\/div>\n<p><strong>Installing the Sensor<\/strong><\/p>\n<p>The sensor has three pins, the middle of which is not used.\u00a0 I soldered on a length of 2-conductor 24 gauge stranded speaker wire and mounted one of the DC barrel plugs on the end.\u00a0 I also used several layers of heat shrink tubing to help stabilize the soldered joint.<\/p>\n<p>The sensor has a long stem with only the round pad on the end being the actual sensor.\u00a0 I bent the sensor to about 90 degrees, and used electrical tape to mount it to the tip of the sword.\u00a0 Be sure to not tape tightly over the sensor &#8211; just enough tape to hold it in place is best.\u00a0 Taping tightly will cause the sensor to read higher pressure when no strike is occurring &#8211; it can&#8217;t tell if the pressure on it is from an impact or from the tape.<\/p>\n<div id=\"attachment_63\" style=\"width: 235px\" class=\"wp-caption alignnone\"><a href=\"http:\/\/yehudaheraldry.com\/blog\/wp-content\/uploads\/2014\/09\/IMG_0766.jpg\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-63\" class=\"size-medium wp-image-63\" src=\"http:\/\/yehudaheraldry.com\/blog\/wp-content\/uploads\/2014\/09\/IMG_0766-225x300.jpg\" alt=\"Sensor mounted on sword tip\" width=\"225\" height=\"300\" srcset=\"http:\/\/yehudaheraldry.com\/blog\/wp-content\/uploads\/2014\/09\/IMG_0766-225x300.jpg 225w, http:\/\/yehudaheraldry.com\/blog\/wp-content\/uploads\/2014\/09\/IMG_0766-768x1024.jpg 768w\" sizes=\"auto, (max-width: 225px) 100vw, 225px\" \/><\/a><p id=\"caption-attachment-63\" class=\"wp-caption-text\">Sensor mounted on sword tip<\/p><\/div>\n<p>I then used more tape to secure the wire down the blade.\u00a0 Be sure to allow some slack for when the sword is bent in a strike, as making the wire taught will cause it to rip, most likely separating from the sensor or even damaging the sensor.\u00a0 Another length of speaker wire with barrel jacks on either end serves as an extension cord.\u00a0 Best lengths remain to be determined.<\/p>\n<div id=\"attachment_62\" style=\"width: 235px\" class=\"wp-caption alignnone\"><a href=\"http:\/\/yehudaheraldry.com\/blog\/wp-content\/uploads\/2014\/09\/IMG_0765.jpg\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-62\" class=\"wp-image-62 size-medium\" src=\"http:\/\/yehudaheraldry.com\/blog\/wp-content\/uploads\/2014\/09\/IMG_0765-225x300.jpg\" alt=\"IMG_0765\" width=\"225\" height=\"300\" srcset=\"http:\/\/yehudaheraldry.com\/blog\/wp-content\/uploads\/2014\/09\/IMG_0765-225x300.jpg 225w, http:\/\/yehudaheraldry.com\/blog\/wp-content\/uploads\/2014\/09\/IMG_0765-768x1024.jpg 768w\" sizes=\"auto, (max-width: 225px) 100vw, 225px\" \/><\/a><p id=\"caption-attachment-62\" class=\"wp-caption-text\">Installed wire and connectors<\/p><\/div>\n<p><strong>Firmware<\/strong><\/p>\n<p>Firmware is loaded onto the Arduino using its free IDE, available at <a href=\"http:\/\/arduino.cc\">arduino.cc<\/a>. The code I used is based on the <a href=\"http:\/\/forum.arduino.cc\/index.php?topic=228549.0\">AnalogBinLogger <\/a>written by Arduino Forum user fat16lib.\u00a0 To begin with, download the code from the forum and install as specified in the readme file.<\/p>\n<p>The code needs to be modified to work in this application.\u00a0 Download my version of the file here: <a href=\"http:\/\/yehudaheraldry.com\/AnalogBinLogger.ino\">http:\/\/yehudaheraldry.com\/AnalogBinLogger.ino<\/a> and upload it to the Arduino.<\/p>\n<p><strong>Using the Digital Rapier<\/strong><\/p>\n<p>The recorder is turned on by pushing the on-off switch.\u00a0 The green LED will illuminate as long as power is on.\u00a0 To start recording, press the start button.\u00a0 The red LED will illuminate to show it&#8217;s recording.\u00a0 Press the stop button to stop recording (occasionally, several button presses are required, I&#8217;m not sure why).\u00a0 The red LED will turn off.\u00a0 It is important that the unit is not powered off while the red LED is lit, or the data will be corrupted.<\/p>\n<p><strong>Data<\/strong><\/p>\n<p>The data recorded by the system is a .csv file with a single column of values from 0 to 1024.\u00a0 1024 represents the resistance of the FSR, with 1024 being infinite resistance (no load) while 0 represents no resistance (maximum load &#8211; around 100lb, but needs to be determined).\u00a0 Unfortunately, resistance is non-linear with load so we need to use conductance, instead.\u00a0 Conductance is equal to 1\/resistance and is linear with load.<\/p>\n<p>The data also has a lot of &#8220;dead air&#8221; &#8211; time when no hits occurred but data is still collected, with values around 1024 being recorded.\u00a0 This can result in large data files with little actual data, making it hard to graph and\/or analyze.<\/p>\n<p>A sample data file as it comes from recorder can be seen here: <a href=\"http:\/\/yehudaheraldry.com\/ANALOG12.CSV\">http:\/\/yehudaheraldry.com\/ANALOG12.CSV<\/a><\/p>\n<p><strong>Software<\/strong><\/p>\n<p>To address these problems, I created a preprocessor.\u00a0 Download it here: <a href=\"http:\/\/yehudaheraldry.com\/PressureProcess.exe\">http:\/\/yehudaheraldry.com\/PressureProcess.exe<\/a> .\u00a0 Open a console window and type &#8220;PressureProcessor.exe -?&#8221; for instructions.\u00a0 The Processor will dump the dead air (using the floor setting), will add a timestamp column, and will compute conductance.\u00a0 Opening the resulting file in excel will allow for an easy graph of the data.<\/p>\n<p>The same data file as processed by the preprocessor can be found here: <a href=\"http:\/\/yehudaheraldry.com\/processed_ANALOG12.CSV\">http:\/\/yehudaheraldry.com\/processed_ANALOG12.CSV<\/a><\/p>\n<p>Please note that the preprocessor only works on Windows computers, and I&#8217;ve only tested it on Win 7 64-bit.\u00a0 Please let me know if other versions of windows cause problems.<\/p>\n<p><strong>To Do<\/strong><\/p>\n<p>The next step is to calibrate the sensor.\u00a0 Currently, the results are just arbitrary values.\u00a0 Once it&#8217;s calibrated, we will know the info in pounds (or Newtons).\u00a0 Additionally, I need to examine the issue of drift.\u00a0 Does the sensor remain in calibration for extended periods of time, or does it go out of-calibration frequently.\u00a0 That will affect usability.<\/p>\n<p><strong>Disclaimer 1<\/strong><\/p>\n<p>I am not an engineer, electrician, or bladesmith.\u00a0 This page exists solely to document my own project.\u00a0 If you chose to use this information to create a similar or identical device you are doing so at your own risk.\u00a0 Doing this may break or void the warranty of the blade, your computer, or the various components used.\u00a0 Rapier combat is an inherently dangerous activity and engaging in it, including for the purposes of collecting this sort of data, may lead to serious physical injury and\/or death.\u00a0 Do so at your own risk.<\/p>\n<p><strong>Disclaimer 2<\/strong><\/p>\n<p>This project is my own, personal, undertaking.\u00a0 It is not an authorized or sponsored project of the SCA, Inc., the office of the Society Rapier Marshal, the East Kingdom, the office of the East Kingdom Marshal of Fence, or any other official group or officer affiliated with the SCA.\u00a0 While I hope the data from this experiment will serve to help with the formulation of policy I have no special ability to write or influence such policy beyond the instruments of reasoned debate available to all members of the rapier community.<\/p>\n<p><a rel=\"license\" href=\"http:\/\/creativecommons.org\/licenses\/by-nc-sa\/4.0\/\"><img decoding=\"async\" alt=\"Creative Commons License\" style=\"border-width:0\" src=\"https:\/\/i.creativecommons.org\/l\/by-nc-sa\/4.0\/88x31.png\" \/><\/a><br \/><span xmlns:dct=\"http:\/\/purl.org\/dc\/terms\/\" property=\"dct:title\">The Digital Rapier Project<\/span> by <a xmlns:cc=\"http:\/\/creativecommons.org\/ns#\" href=\"http:\/\/yehudaheraldry.com\/blog\/digital-rapier-part-1-construction\/\" property=\"cc:attributionName\" rel=\"cc:attributionURL\">Juliean Galak<\/a> is licensed under a <a rel=\"license\" href=\"http:\/\/creativecommons.org\/licenses\/by-nc-sa\/4.0\/\">Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License<\/a>.<br \/>Based on a work at <a xmlns:dct=\"http:\/\/purl.org\/dc\/terms\/\" href=\"http:\/\/forum.arduino.cc\/index.php?topic=228549.0\" rel=\"dct:source\">http:\/\/forum.arduino.cc\/index.php?topic=228549.0<\/a>.<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Background: In SCA rapier combat, determining how hard a thrust hits has been an outstanding question for some time.\u00a0 With the recent discussions of rapier pikes and reduced armor standards, this has become more important.\u00a0 Various mechanical systems have been&hellip; <\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7,6],"tags":[],"class_list":["post-72","post","type-post","status-publish","format-standard","hentry","category-electroncs","category-rapier"],"_links":{"self":[{"href":"http:\/\/yehudaheraldry.com\/blog\/wp-json\/wp\/v2\/posts\/72","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/yehudaheraldry.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/yehudaheraldry.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/yehudaheraldry.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/yehudaheraldry.com\/blog\/wp-json\/wp\/v2\/comments?post=72"}],"version-history":[{"count":14,"href":"http:\/\/yehudaheraldry.com\/blog\/wp-json\/wp\/v2\/posts\/72\/revisions"}],"predecessor-version":[{"id":86,"href":"http:\/\/yehudaheraldry.com\/blog\/wp-json\/wp\/v2\/posts\/72\/revisions\/86"}],"wp:attachment":[{"href":"http:\/\/yehudaheraldry.com\/blog\/wp-json\/wp\/v2\/media?parent=72"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/yehudaheraldry.com\/blog\/wp-json\/wp\/v2\/categories?post=72"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/yehudaheraldry.com\/blog\/wp-json\/wp\/v2\/tags?post=72"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}