{"id":9629,"date":"2014-11-13T21:40:24","date_gmt":"2014-11-14T02:40:24","guid":{"rendered":"http:\/\/embedded-lab.com\/blog\/?p=9629"},"modified":"2014-11-13T21:40:24","modified_gmt":"2014-11-14T02:40:24","slug":"lpc1114-controlled-midi-synthesizer","status":"publish","type":"post","link":"https:\/\/embedded-lab.com\/blog\/lpc1114-controlled-midi-synthesizer\/","title":{"rendered":"LPC1114 controlled Midi Synthesizer"},"content":{"rendered":"<p><span style=\"font-size: 0.95em; line-height: 1.6em;\">Matt Sarnoff built this\u00a0<\/span><a href=\"https:\/\/github.com\/74hc595\/LPC1114-Synthesizer\" target=\"_blank\"><strong>digital monophonic synthesizer<\/strong><\/a> using the\u00a0<a href=\"http:\/\/www.nxp.com\/products\/microcontrollers\/cortex_m0_m0\/LPC1114FN28.html\">NXP LPC1114FN28<\/a>\u00a0ARM Cortex-M0 microcontroller and <a href=\"http:\/\/ww1.microchip.com\/downloads\/en\/DeviceDoc\/21897a.pdf\">MCP4921 SPI DAC<\/a>. It is a midi synthesizer with following features:<\/p>\n<ul>\n<li>4 oscillators; sawtooth or pulse with adjustable duty cycle with coarse and fine tuning<\/li>\n<li>2-pole (&#8220;Chamberlin&#8221;) state-variable filter with lowpass, highpass, and bandpass modes<\/li>\n<li>Attack-release envelopes for amplitude and modulation<\/li>\n<li>Low-frequency oscillator with four shapes (triangle, ramp, square, random)<\/li>\n<li>LFO and\/or modulation envelope can affect filter cutoff frequency, pitch, and pulse width<\/li>\n<li>Keyboard tracking for filter cutoff frequency<\/li>\n<li>Glide with 3 different rate presets<\/li>\n<li>MIDI input; monophonic with last-note priority<\/li>\n<li>250kHz, 12-bit output<\/li>\n<li>Powered by 3 AA batteries<\/li>\n<\/ul>\n<div id=\"attachment_9630\" style=\"width: 595px\" class=\"wp-caption aligncenter\"><a href=\"http:\/\/embedded-lab.com\/blog\/?attachment_id=9630\" rel=\"attachment wp-att-9630\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-9630\" class=\"size-full wp-image-9630\" alt=\"ARM-powered midi synthesizer\" src=\"http:\/\/embedded-lab.com\/blog\/wp-content\/uploads\/2014\/11\/midi.png\" width=\"585\" height=\"421\" srcset=\"https:\/\/embedded-lab.com\/blog\/wp-content\/uploads\/2014\/11\/midi.png 585w, https:\/\/embedded-lab.com\/blog\/wp-content\/uploads\/2014\/11\/midi-550x395.png 550w\" sizes=\"auto, (max-width: 585px) 100vw, 585px\" \/><\/a><p id=\"caption-attachment-9630\" class=\"wp-caption-text\">ARM-powered midi synthesizer<\/p><\/div>\n","protected":false},"excerpt":{"rendered":"<p>Matt Sarnoff built this\u00a0digital monophonic synthesizer using the\u00a0NXP LPC1114FN28\u00a0ARM Cortex-M0 microcontroller and MCP4921 SPI DAC. It is a midi synthesizer with following features: 4 oscillators; sawtooth or pulse with adjustable duty cycle with coarse and fine tuning 2-pole (&#8220;Chamberlin&#8221;) state-variable filter with lowpass, highpass, and bandpass modes Attack-release envelopes for amplitude and modulation Low-frequency oscillator with four shapes (triangle, ramp, square, random) LFO and\/or modulation envelope can affect filter cutoff frequency, pitch, and pulse width Keyboard tracking for filter cutoff frequency Glide with 3 different rate presets MIDI input; monophonic with last-note priority 250kHz, 12-bit output Powered by 3 AA<\/p>\n","protected":false},"author":1,"featured_media":9630,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1024],"tags":[1026,997,1025],"class_list":["post-9629","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-arm-projects","tag-arm-processor","tag-midi","tag-midi-synthesizer"],"_links":{"self":[{"href":"https:\/\/embedded-lab.com\/blog\/wp-json\/wp\/v2\/posts\/9629","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/embedded-lab.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/embedded-lab.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/embedded-lab.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/embedded-lab.com\/blog\/wp-json\/wp\/v2\/comments?post=9629"}],"version-history":[{"count":4,"href":"https:\/\/embedded-lab.com\/blog\/wp-json\/wp\/v2\/posts\/9629\/revisions"}],"predecessor-version":[{"id":9642,"href":"https:\/\/embedded-lab.com\/blog\/wp-json\/wp\/v2\/posts\/9629\/revisions\/9642"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/embedded-lab.com\/blog\/wp-json\/wp\/v2\/media\/9630"}],"wp:attachment":[{"href":"https:\/\/embedded-lab.com\/blog\/wp-json\/wp\/v2\/media?parent=9629"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/embedded-lab.com\/blog\/wp-json\/wp\/v2\/categories?post=9629"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/embedded-lab.com\/blog\/wp-json\/wp\/v2\/tags?post=9629"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}