{"id":1289,"date":"2020-09-10T12:17:30","date_gmt":"2020-09-10T15:17:30","guid":{"rendered":"https:\/\/wordpress.argentinaroom.com.ar\/?p=1289"},"modified":"2023-04-20T22:54:25","modified_gmt":"2023-04-21T01:54:25","slug":"nodo-minirepetidor-hotspot-en-que-difieren","status":"publish","type":"post","link":"https:\/\/www.argentinaroom.com.ar\/?p=1289","title":{"rendered":"MMDVM que es y c\u00f3mo funciona"},"content":{"rendered":"<div id=\"pl-gb1289-6a1a34ea1350d\"  class=\"panel-layout\" ><div id=\"pg-gb1289-6a1a34ea1350d-0\"  class=\"panel-grid panel-no-style\" ><div id=\"pgc-gb1289-6a1a34ea1350d-0-0\"  class=\"panel-grid-cell\" ><div id=\"panel-gb1289-6a1a34ea1350d-0-0-0\" class=\"so-panel widget widget_sow-headline panel-first-child panel-last-child\" data-index=\"0\" ><div\n\t\t\t\n\t\t\tclass=\"so-widget-sow-headline so-widget-sow-headline-default-f9562feb7fac-1289\"\n\t\t\t\n\t\t><div class=\"sow-headline-container \">\n\t\t\t\t\t\t<div class=\"decoration\">\n\t\t\t\t\t\t<div class=\"decoration-inside\"><\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t\t<h2 class=\"sow-sub-headline\">\n\t\t\t\t\t\tMMDVM es el acr\u00f3nimo ingles de Multi Mode Digital Voice Modem, en otras palabras es un MODEM MULTIMODO de VOZ DIGITAL.\t\t\t\t\t\t<\/h2>\n\t\t\t\t\t\t<\/div>\n<\/div><\/div><\/div><\/div><div id=\"pg-gb1289-6a1a34ea1350d-1\"  class=\"panel-grid panel-no-style\" ><div id=\"pgc-gb1289-6a1a34ea1350d-1-0\"  class=\"panel-grid-cell\" ><div id=\"panel-gb1289-6a1a34ea1350d-1-0-0\" class=\"so-panel widget widget_sow-editor panel-first-child panel-last-child\" data-index=\"1\" ><div\n\t\t\t\n\t\t\tclass=\"so-widget-sow-editor so-widget-sow-editor-base\"\n\t\t\t\n\t\t>\n<div class=\"siteorigin-widget-tinymce textwidget\">\n\t<p style=\"text-align: justify;\"><strong><em>Porque MODEM<\/em><\/strong>? , porque la voz digital al igual que cualquier modo digital debe ser transferido utilizando alg\u00fan modo de modulaci\u00f3n; para los modos <strong>DMR y FUSION<\/strong> es el modelo 4 FSK (Modulaci\u00f3n de 4 niveles) que permite tener 4 s\u00edmbolos definidos ( {11} -1.944 {10} -0.648 &lt; CENTRO &gt; {00} +0.648, {01} +1.944 ) a una tasa de 4800 o 9600 bps. Para D-Star el modelo empleado fue el GMSK (Modulaci\u00f3n por desplazamiento m\u00ednimo gaussiano).<\/p>\n<p style=\"text-align: justify;\">Estas se\u00f1ales deben ser codificadas y decodificadas para generar u obtener los marcos que nos permite intercambiar nuestra voz, aqu\u00ed es donde interviene el hardware de la MMDVM.<\/p>\n<p style=\"text-align: justify;\">Siendo una combinaci\u00f3n de hardware y software, este modem fue evolucionando a trav\u00e9s del tiempo. En sus comienzos se baso en un software escrito para el micro controlador ARDUINO el que junto a una PLACA externa de FILTROS toma el audio de nuestro equipo de radio y lo procesa para de esta forma entregar los marcos de voz digital en el puerto USB. Normalmente desde este se env\u00eda a un Raspberry o Computadora que junto a otro software se encargara de manejar estos marcos digital para enviarlos hacia Internet, l\u00f3gicamente el este proceso es de ida y vuelta.<\/p>\n<p style=\"text-align: justify;\">Debido a problemas de velocidad ocasionado por la lentitud del ARDUINO para una tarea tan compleja, se comenz\u00f3 a probar otros micro controladores, como ser el STM32 NUCLEO que al utilizar el STM32 como CPU le permit\u00eda operar con mejor eficiencia.<\/p>\n<p style=\"text-align: justify;\">Posteriormente todo este hardware y software se uni\u00f3 en una sola placa que permit\u00eda montarla sobre el puerto <strong>GPIO<\/strong> de las <strong>RaspBerry<\/strong> haciendo m\u00e1s peque\u00f1a la instalaci\u00f3n.<\/p>\n<p style=\"text-align: justify;\">Con la incorporaci\u00f3n del chip <em>ADF7021 el cual es un transceptor de baja potencia<\/em>, amplia gama de frecuencia y con un modulador 4FSK y GMSK incorporado nacieron los HOTSPOT que simplificaron el uso domestico, sin olvidar las placas que sumaron un segundo chip ADF7021 para dar paso a las peque\u00f1as repetidoras de vos digital.<\/p>\n<p style=\"text-align: justify;\">Les dejo una peque\u00f1a colecci\u00f3n de im\u00e1genes para ver gr\u00e1ficamente la evoluci\u00f3n de estas<\/p>\n<p style=\"text-align: center;\"><img loading=\"lazy\" decoding=\"async\" class=\"\" src=\"https:\/\/www.argentinaroom.com.ar\/images\/118824087_3283895788352769_1977609161595699562_o4.jpg\" width=\"412\" height=\"552\" \/>\u00a0 \u00a0 <img loading=\"lazy\" decoding=\"async\" class=\"\" src=\"https:\/\/www.argentinaroom.com.ar\/images\/118951314_3283895675019447_5335640118392660594_o1.jpg\" width=\"412\" height=\"552\" \/><\/p>\n<p style=\"text-align: center;\"><img loading=\"lazy\" decoding=\"async\" class=\"\" src=\"https:\/\/www.argentinaroom.com.ar\/images\/119060293_3283895831686098_4126389661732840508_o5.jpg\" width=\"412\" height=\"552\" \/>\u00a0 \u00a0 \u00a0<img loading=\"lazy\" decoding=\"async\" class=\"\" src=\"https:\/\/www.argentinaroom.com.ar\/images\/119099246_3283895708352777_7073249977397473450_o3.jpg\" width=\"411\" height=\"551\" \/><\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<\/div>\n<\/div><\/div><\/div><\/div><\/div>\n\n\n<p class=\"has-vivid-cyan-blue-color has-text-color\"><strong>Por LU4AE &#8211; Claudio<\/strong><\/p>\n\n\n\n<div class=\"wp-block-comments\">\n\n\t<div id=\"respond\" class=\"comment-respond wp-block-post-comments-form\">\n\t\t<h3 id=\"reply-title\" class=\"comment-reply-title\">Deja un comentario <small><a rel=\"nofollow\" id=\"cancel-comment-reply-link\" href=\"\/index.php?rest_route=%2Fwp%2Fv2%2Fposts%2F1289#respond\" style=\"display:none;\">Cancelar respuesta<\/a><\/small><\/h3><form action=\"https:\/\/www.argentinaroom.com.ar\/wp-comments-post.php\" method=\"post\" id=\"commentform\" class=\"comment-form\"><p class=\"comment-notes\"><span id=\"email-notes\">Tu direcci\u00f3n de correo electr\u00f3nico no ser\u00e1 publicada.<\/span> <span class=\"required-field-message\">Los campos obligatorios est\u00e1n marcados con <span class=\"required\">*<\/span><\/span><\/p><p class=\"comment-form-comment\"><label for=\"comment\">Comentario <span class=\"required\">*<\/span><\/label> <textarea id=\"comment\" name=\"comment\" cols=\"45\" rows=\"8\" maxlength=\"65525\" required><\/textarea><\/p><p class=\"comment-form-author\"><label for=\"author\">Nombre <span class=\"required\">*<\/span><\/label> <input id=\"author\" name=\"author\" type=\"text\" value=\"\" size=\"30\" maxlength=\"245\" autocomplete=\"name\" required \/><\/p>\n<p class=\"comment-form-email\"><label for=\"email\">Correo electr\u00f3nico <span class=\"required\">*<\/span><\/label> <input id=\"email\" name=\"email\" type=\"email\" value=\"\" size=\"30\" maxlength=\"100\" aria-describedby=\"email-notes\" autocomplete=\"email\" required \/><\/p>\n<p class=\"comment-form-url\"><label for=\"url\">Web<\/label> <input id=\"url\" name=\"url\" type=\"url\" value=\"\" size=\"30\" maxlength=\"200\" autocomplete=\"url\" \/><\/p>\n<p class=\"comment-form-cookies-consent\"><input id=\"wp-comment-cookies-consent\" name=\"wp-comment-cookies-consent\" type=\"checkbox\" value=\"yes\" \/> <label for=\"wp-comment-cookies-consent\">Guardar mi nombre, correo electr\u00f3nico y sitio web en este navegador para la pr\u00f3xima vez que haga un comentario.<\/label><\/p>\n<p class=\"form-submit\"><input name=\"submit\" type=\"submit\" id=\"submit\" class=\"submit\" value=\"Publicar comentario\" \/> <input type='hidden' name='comment_post_ID' value='1289' id='comment_post_ID' \/>\n<input type='hidden' name='comment_parent' id='comment_parent' value='0' \/>\n<\/p><p style=\"display: none;\"><input type=\"hidden\" id=\"akismet_comment_nonce\" name=\"akismet_comment_nonce\" value=\"55bda68235\" \/><\/p><p style=\"display: none !important;\" class=\"akismet-fields-container\" data-prefix=\"ak_\"><label>&#916;<textarea name=\"ak_hp_textarea\" cols=\"45\" rows=\"8\" maxlength=\"100\"><\/textarea><\/label><input type=\"hidden\" id=\"ak_js_1\" name=\"ak_js\" value=\"138\"\/><script>document.getElementById( \"ak_js_1\" ).setAttribute( \"value\", ( new Date() ).getTime() );<\/script><\/p><\/form>\t<\/div><!-- #respond -->\n\t<\/div>\n","protected":false},"excerpt":{"rendered":"<p>&hellip; 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