{"id":76,"date":"2011-03-14T08:55:42","date_gmt":"2011-03-14T08:55:42","guid":{"rendered":"http:\/\/www.daveakerman.com\/?p=76"},"modified":"2011-03-14T08:55:42","modified_gmt":"2011-03-14T08:55:42","slug":"name-that-tune","status":"publish","type":"post","link":"http:\/\/www.daveakerman.com\/?p=76","title":{"rendered":"Name That Tune"},"content":{"rendered":"<p>Next job was to get the transmitter running and prove it was transmitting correctly by hooking up a receiver to decode the radio signal. \u00a0The program waggles a single output pin which is then reduced in amplitude and offset a little to match the transmitter&#8217;s requirements. \u00a0Here&#8217;s the resulting signal fed to the transmitter:<\/p>\n<p><a rel=\"attachment wp-att-77\" href=\"http:\/\/www.daveakerman.com\/?attachment_id=77\"><img decoding=\"async\" loading=\"lazy\" class=\"aligncenter size-large wp-image-77\" title=\"scope\" src=\"http:\/\/www.daveakerman.com\/wp-content\/uploads\/2011\/03\/scope-1024x130.jpg\" alt=\"\" width=\"1024\" height=\"130\" srcset=\"http:\/\/www.daveakerman.com\/wp-content\/uploads\/2011\/03\/scope-1024x130.jpg 1024w, http:\/\/www.daveakerman.com\/wp-content\/uploads\/2011\/03\/scope-300x38.jpg 300w, http:\/\/www.daveakerman.com\/wp-content\/uploads\/2011\/03\/scope.jpg 1064w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/a><\/p>\n<p>This signal alters the transmitter&#8217;s frequency a little, and when picked up on a ham radio has a distinctive &#8220;Teleprinter&#8221; warble. \u00a0I don&#8217;t yet have such a radio, so instead I generated that warble by using a tiny receiver (Radiometrix NRX2, matching the NTX2 transmitter) and fed its output into the sweep input of an audio signal generator. \u00a0The result is the same as the radio ham setup, except that the two tones of the warble will be different. \u00a0That doesn&#8217;t matter since the decoding software can easily be configured to match the tones received. \u00a0So, here is a screen-shot from that decoder, showing the message that was transmitter over the airwaves, and picked up by my receiver about 20cm away!<\/p>\n<p><a rel=\"attachment wp-att-78\" href=\"http:\/\/www.daveakerman.com\/?attachment_id=78\"><img decoding=\"async\" loading=\"lazy\" class=\"aligncenter size-full wp-image-78\" title=\"dlfldigi\" src=\"http:\/\/www.daveakerman.com\/wp-content\/uploads\/2011\/03\/dlfldigi.jpg\" alt=\"\" width=\"551\" height=\"506\" srcset=\"http:\/\/www.daveakerman.com\/wp-content\/uploads\/2011\/03\/dlfldigi.jpg 551w, http:\/\/www.daveakerman.com\/wp-content\/uploads\/2011\/03\/dlfldigi-300x275.jpg 300w\" sizes=\"(max-width: 551px) 100vw, 551px\" \/><\/a><\/p>\n<p>This may look similar to an earlier post, but that time there was no radio signal involved &#8211; this time it&#8217;s much closer to what the balloon payload will be doing. \u00a0Next step here is to change the test message to be real balloon data (GPS, temperatures etc.).<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Next job was to get the transmitter running and prove it was transmitting correctly by hooking up a receiver to decode the radio signal. \u00a0The program waggles a single output pin which is then reduced in amplitude and offset a little to match the transmitter&#8217;s requirements. \u00a0Here&#8217;s the resulting signal [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[],"_links":{"self":[{"href":"http:\/\/www.daveakerman.com\/index.php?rest_route=\/wp\/v2\/posts\/76"}],"collection":[{"href":"http:\/\/www.daveakerman.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.daveakerman.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.daveakerman.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.daveakerman.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=76"}],"version-history":[{"count":3,"href":"http:\/\/www.daveakerman.com\/index.php?rest_route=\/wp\/v2\/posts\/76\/revisions"}],"predecessor-version":[{"id":81,"href":"http:\/\/www.daveakerman.com\/index.php?rest_route=\/wp\/v2\/posts\/76\/revisions\/81"}],"wp:attachment":[{"href":"http:\/\/www.daveakerman.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=76"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.daveakerman.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=76"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.daveakerman.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=76"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}