{"id":2884,"date":"2018-12-29T14:39:43","date_gmt":"2018-12-29T19:39:43","guid":{"rendered":"http:\/\/centipede.serve101.org\/?p=2884"},"modified":"2019-02-15T13:47:03","modified_gmt":"2019-02-15T18:47:03","slug":"recently-asked-questions","status":"publish","type":"post","link":"https:\/\/centipede.serve101.org\/?p=2884","title":{"rendered":"Recently Asked Questions"},"content":{"rendered":"<p><span style=\"color: #0000ff;\"><strong>&gt; How can I recover when my SD card is corrupted?<\/strong><\/span><\/p>\n<p>This condition is sometimes referred to a &#8220;bricking&#8221; your device. It is unlikely this will happen to you, but if it does, follow the steps below to recover. But first a few words of caution: While following these steps, it is likely that your Windows machine will suggest formatting your SD card.\u00a0Make sure you cancel these suggestions. If you allow Windows to format your card, it will not work in the Centipede unless you repeat all the steps below.<\/p>\n<p>1) Formatting the SD card. Depending on the type of corruption, you may have to format the SD card. You will most likely need to take this step if, at some point, you let Windows format it. Repeating myself, do not let Windows format your SD card, instead use the SD Memory Card Formatter, which can be downloaded here:\u00a0<a href=\"https:\/\/www.sdcard.org\/downloads\/formatter_4\/eula_windows\/index.html\" target=\"_blank\" rel=\"noopener\">SD Memory Card Formatter<\/a>.\u00a0 Be sure to select the &#8220;Overwrite Format&#8221; option when formatting.\u00a0 This software is available free of charge at the link shown above. After you have formatted the card with SDFormatter, Windows is likely to offer to once again format the SD card you just formatted. Cancel this suggestion.<\/p>\n<p>2) Once you have formatted the SD card, download the latest version of the Centipede, selecting the &#8220;img&#8221; file. The &#8220;img&#8221; files can be found on this page: <a href=\"https:\/\/centipede.serve101.org\/?page_id=439\" target=\"_blank\" rel=\"noopener\">Software Images<\/a><\/p>\n<p>3) Now use the program Win32DiskImager to transfer the file downloaded in step 2 onto the SD card. Windows is likely to offer to format the SD card, possibly several times during this step. Cancel these suggestions.<\/p>\n<p>4) Last step, install the SD card into the Centipede card slot. Make sure it is properly seated. The socket is spring loaded, so make sure you have it fully inserted in the deeper of the two positions. Now power up your Centipede to test for success. If you carefully followed all the steps, and the Centipede still does not work, it is possible you have a defective or incompatible SD card. In this FAQ, there is a link to a page which lists SD card which have been tested, and are expected to work. If all else fails, you can also obtain a new, fully programmed 8-gig replacement SD card from us, for a nominal fee.<\/p>\n<p><span style=\"color: #0000ff;\"><strong>&gt; Are the estim channels electrically isolated from each other, and<\/strong><\/span><br \/>\n<span style=\"color: #0000ff;\"><strong>&gt; from the power ground? How is the isolation done?<\/strong><\/span><\/p>\n<p>The channel outputs are not electrically connected to each other<br \/>\nor to a &#8220;system&#8221; ground.\u00a0 Both the positive and negative wires are<br \/>\nisolated by channel.\u00a0 Each output comes from a transformer winding<br \/>\n(each channel has it&#8217;s own transformer) and then through a series<br \/>\nresistor.\u00a0 \u00a0 BTW, each output is a voltage limited, current source.<\/p>\n<p>&gt; It sounds like the waveform generation is not performed by the main<br \/>\n&gt; processor (linux system), but rather by a separate micro controller.<br \/>\n&gt; Is that correct? Does the waveform generator ensure that only one<br \/>\n&gt; output is active at a time? Are there separate waveform generators<br \/>\n&gt; for each output or board?<\/p>\n<p>Correct, the waveforms are generated by microprocessors.\u00a0 There are<br \/>\nthree microprocessors in the 416.\u00a0 One micro, controls the power and<br \/>\nbattery charging, the other two generate waveforms (one for each<br \/>\nboard).\u00a0 Each output can run or not, independent of what the other<br \/>\noutputs are doing.\u00a0 All can be on at once, or any combination.\u00a0 The<br \/>\nwaveform on each output is also independent of the waveform choices on<br \/>\nother outputs.\u00a0 Lastly output signal levels are independent of each<br \/>\nother.\u00a0 Pods, also contain microprocessors.<\/p>\n<p><span style=\"color: #0000ff;\"><strong>&gt; Similarly, is the viby pod electrically isolated from the other<\/strong><\/span><br \/>\n<span style=\"color: #0000ff;\"><strong>&gt; outputs?<\/strong><\/span><\/p>\n<p>Two kinds of vibrators are supported via pods.\u00a0 You can drive 3 volt DC<br \/>\n(battery power) vibrators (via the viby pod) or 120-AC vibrators (via<br \/>\nthe regulator pod).\u00a0 The outputs from pods are completely isolated from<br \/>\nthe main power box and from other pods.<\/p>\n<p>On the regulator pod, the neutral and grounds are common-ed, but the<br \/>\nhot wires wires are separately controlled, but driven from a common<br \/>\nreceptacle.\u00a0 All the AC wiring is optically coupled to prevent the AC<br \/>\nvoltage from getting into any of the other circuitry.<\/p>\n<p><span style=\"color: #0000ff;\"><strong>&gt; How do you process the audio files for estim? Do you convert the<\/strong><\/span><br \/>\n<span style=\"color: #0000ff;\"><strong>&gt; audio signal to a lower frequency?<\/strong><\/span><\/p>\n<p>Stereo Audio is processed as follows:\u00a0 The left and right channels are<br \/>\nfirst limited to 0-1 volt to prevent damage to the box.\u00a0 They are then<br \/>\npeak detected, converted to digital and distributed to the outputs.<br \/>\nAny eStim output can be set to be driven by either the right, left, or<br \/>\ncenter (left+right) signal.\u00a0 Each output can also have minimum and<br \/>\nmaximum limit set and each has it&#8217;s own gain control.\u00a0 You can have<br \/>\nsome outputs driven by audio, while others are driven by digital<br \/>\nwaveforms at the same time.<\/p>\n<p><span style=\"color: #0000ff;\"><strong>&gt; Can you connect the audio to a viby channel, and if so, how is the<\/strong><\/span><br \/>\n<span style=\"color: #0000ff;\"><strong>&gt; audio processed?<\/strong><\/span><\/p>\n<p>At present, only eStim outputs can be driven by audio, although adding<br \/>\naudio drive to other outputs is possible if there is sufficient interest in<br \/>\ndoing so.<\/p>\n<p><span style=\"color: #0000ff;\"><strong>&gt; It looks like there is only one audio output. So you cannot have<\/strong><\/span><br \/>\n<span style=\"color: #0000ff;\"><strong>&gt; different audio for the 4 estim outputs. Is that correct? Could you<\/strong><\/span><br \/>\n<span style=\"color: #0000ff;\"><strong>&gt; use a USB audio device to provide a different audio input to the 2nd<\/strong><\/span><br \/>\n<span style=\"color: #0000ff;\"><strong>&gt; set of two estim outputs?<\/strong><\/span><\/p>\n<p>The Audio-Input that drives the outputs is provided via a front panel<br \/>\njack.\u00a0 The audio output jack (back panel) is not used to drive outputs<br \/>\nunless you use a cable to interconnect the output and input jacks. We<br \/>\nhave future plans to convert to gStreamer support, that would allow<br \/>\nmore audio files to be playing at the same time, we believe.<\/p>\n<p><span style=\"color: #0000ff;\"><strong>&gt; I am concerned about the lack of manual level controls. It looks like<\/strong><\/span><br \/>\n<span style=\"color: #0000ff;\"><strong>&gt; to adjust a level I have to 1) move a slider in the UI, and then 2)<\/strong><\/span><br \/>\n<span style=\"color: #0000ff;\"><strong>&gt; click an apply button. It seems to me this two-stage approach would<\/strong><\/span><br \/>\n<span style=\"color: #0000ff;\"><strong>&gt; make it difficult to adjust levels to a comfortable level. Also,<\/strong><\/span><br \/>\n<span style=\"color: #0000ff;\"><strong>&gt; there are times when you want to turn down levels immediately! Is<\/strong><\/span><br \/>\n<span style=\"color: #0000ff;\"><strong>&gt; there any way to provide more immediate and quickly responding<\/strong><\/span><br \/>\n<span style=\"color: #0000ff;\"><strong>&gt; control?<\/strong><\/span><\/p>\n<p>Yes, we could add an option to make hitting the APPLY button optional.<br \/>\nIn fact, you could make that change yourself if you know JavaScript.<br \/>\nWe personally like the APPLY button, and recommend you try using the<br \/>\nsystem with that button, before making it no longer necessary.\u00a0 You can<br \/>\nalso add external variable resistors if you have a setup requiring<br \/>\nthem.<\/p>\n<p><span style=\"color: #0000ff;\"><strong>&gt; I don&#8217;t see any mention of tri-phase connections (where two channels<\/strong><\/span><br \/>\n<span style=\"color: #0000ff;\"><strong>&gt; are used with a common return). Can the controller be used in a tri-<\/strong><\/span><br \/>\n<span style=\"color: #0000ff;\"><strong>&gt; phase manner? Do you provide any modes specific to this kind of use?<\/strong><\/span><\/p>\n<p>You can certainly connect outputs to use a common ground.\u00a0 We have not<br \/>\nyet found such a connection to be needed, but there is nothing in the<br \/>\nproduct that stops you from using it this way.<\/p>\n<p><span style=\"color: #0000ff;\"><strong>&gt; I want to use a larger SD card.\u00a0\u00a0What cards are compatible with the<\/strong><\/span><br \/>\n<span style=\"color: #0000ff;\"><strong>&gt; Centipede 416 \/ Centipede 416-AC?<\/strong><\/span><\/p>\n<p>Start with this link which lists SD cards found to be compatible by third parties.<br \/>\n<a href=\"https:\/\/elinux.org\/RPi_SD_cards\" target=\"_blank\" rel=\"noopener\">List of SD cards<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>&gt; How can I recover when my SD card is corrupted? This condition is sometimes referred to a &#8220;bricking&#8221; your device. It is unlikely this will happen to you, but if it does, follow the steps below to recover. But first a few words of caution: While following these steps, it is likely that your [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_bbp_topic_count":0,"_bbp_reply_count":0,"_bbp_total_topic_count":0,"_bbp_total_reply_count":0,"_bbp_voice_count":0,"_bbp_anonymous_reply_count":0,"_bbp_topic_count_hidden":0,"_bbp_reply_count_hidden":0,"_bbp_forum_subforum_count":0,"footnotes":""},"categories":[1],"tags":[],"class_list":["post-2884","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/centipede.serve101.org\/index.php?rest_route=\/wp\/v2\/posts\/2884","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/centipede.serve101.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/centipede.serve101.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/centipede.serve101.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/centipede.serve101.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2884"}],"version-history":[{"count":7,"href":"https:\/\/centipede.serve101.org\/index.php?rest_route=\/wp\/v2\/posts\/2884\/revisions"}],"predecessor-version":[{"id":3104,"href":"https:\/\/centipede.serve101.org\/index.php?rest_route=\/wp\/v2\/posts\/2884\/revisions\/3104"}],"wp:attachment":[{"href":"https:\/\/centipede.serve101.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2884"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/centipede.serve101.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2884"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/centipede.serve101.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2884"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}