{"id":5712,"date":"2019-07-07T20:42:55","date_gmt":"2019-07-07T12:42:55","guid":{"rendered":"http:\/\/www.mateksys.com\/?p=5712"},"modified":"2025-11-08T11:01:54","modified_gmt":"2025-11-08T03:01:54","slug":"diagnosing-fc","status":"publish","type":"post","link":"https:\/\/www.mateksys.com\/?p=5712","title":{"rendered":"FAQs and user guide"},"content":{"rendered":"\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-42em28-b2fcc25a11f31a598c5202a8074d80cf\">\n#top .av-special-heading.av-42em28-b2fcc25a11f31a598c5202a8074d80cf{\npadding-bottom:10px;\n}\nbody .av-special-heading.av-42em28-b2fcc25a11f31a598c5202a8074d80cf .av-special-heading-tag .heading-char{\nfont-size:25px;\n}\n.av-special-heading.av-42em28-b2fcc25a11f31a598c5202a8074d80cf .av-subheading{\nfont-size:15px;\n}\n<\/style>\n<div  class='av-special-heading av-42em28-b2fcc25a11f31a598c5202a8074d80cf av-special-heading-h2 blockquote modern-quote modern-centered  avia-builder-el-0  el_before_av_notification  avia-builder-el-first '><h2 class='av-special-heading-tag'  itemprop=\"headline\"  >FAQ<\/h2><div class=\"special-heading-border\"><div class=\"special-heading-inner-border\"><\/div><\/div><\/div>\n<div id='avia-messagebox-' class='avia_message_box av_notification av-l85xd8nk-3d1de54cf17593b22bbea93a5d8a266c avia-color-red avia-size-normal avia-icon_select-yes avia-border-  avia-builder-el-1  el_after_av_heading  el_before_av_tab_container ' ><span class='avia_message_box_title' >Note<\/span><div class=\"avia_message_box_content\"><span class='avia_message_box_icon' aria-hidden='true' data-av_icon='\ue83e' data-av_iconfont='entypo-fontello'><\/span><p>Do not use excessive flux !!! Flux mixed with soldering dross is conductive !!!<\/p>\n<\/div><\/div>\n<div  class='tabcontainer av-jypgykj9-1e3aae821f31b710e73aa215d4083d9f sidebar_tab sidebar_tab_left  avia-builder-el-2  el_after_av_notification  el_before_av_hr  border_tabs' role='tablist'>\n<section class='av_tab_section av_tab_section av-1y4cbk-9bb7069e82cd640250584f3684e151fd'  itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='tab active_tab' role='tab' tabindex='0' data-fake-id='#tab-id-1' aria-controls='tab-id-1-content'  itemprop=\"headline\" >FC can\u2018t connect to configurator, or can\u2019t go into DFU mode.<\/div><div id='tab-id-1-content' class='tab_content active_tab_content' aria-hidden=\"false\"><div class='tab_inner_content invers-color'  itemprop=\"text\" ><p><strong>Red\/Blue\/Green LEDs light up\/blink normal when FC booting, but FC can\u2018t connect to configurator, or can\u2019t go into DFU mode.<\/strong><\/p>\n<ul>\n<li>Intall DFU and STM VCP drivers,\u00a0Click\u00a0<span style=\"color: #0000ff;\"><a style=\"color: #0000ff;\" href=\"https:\/\/www.mateksys.com\/?p=5159#tab-id-1\" target=\"_blank\" rel=\"noopener\">Installing Betaflight\/INAV<\/a><\/span>\u00a0for details<\/li>\n<li><span style=\"color: #0000ff;\">Make sure INAV firmware version is compatible with configurator version, e.g. use configurator 3.0 for fw 3.0.x,\u00a0 use configurator 2.6 for fw 2.6.x<\/span><\/li>\n<li>Unplug USB and close configurator,\u00a0 plug USB back in and run configurator again.<\/li>\n<li>Try other USB cables<\/li>\n<li>Check if there is dry joint on USB connector pins<\/li>\n<li>There is known bug that INAV configurator <strong>Chrome version<\/strong> can&#8217;t flash firmware in DFU mode.<\/li>\n<li><span style=\"color: #0000ff;\">If GPS or other peripherals are connected to <strong>UART1 or UART3 of F4\/F7\/H7<\/strong> chip and these peripherals are powered ON while connecting USB.\u00a0 \u00a0FC can\u2019t enter DFU mode. It is related to\u00a0DFU protocol used in the STM32 bootloader, not hardware and PC driver issue.<\/span><\/li>\n<\/ul>\n<ul>\n<li><strong>Unsolder\/disconnect all peripherals from FC board. Try connecting bare FC to configurator.<\/strong><\/li>\n<li>Test resistance between 3v3 and G.\u00a0 normal resistance should be K ohm class.<\/li>\n<li>DFU mode can&#8217;t be bricked.\u00a0 Try reflashing it in DFU mode.<\/li>\n<\/ul>\n<p><strong>Flight controller freeze when booting<\/strong><\/p>\n<ul>\n<li>Make sure you have it flashed with right target\/firmware.<\/li>\n<li>Try reflashing it in DFU mode.<\/li>\n<li>It is a good practice to type CLI &#8220;defaults&#8221; after every flashing to erase fragment of data\/settings.<\/li>\n<li>DO NOT try to use a diff or dump from other version.\u00a0 Start settings from scratch.<\/li>\n<\/ul>\n<\/div><\/div><\/section>\n<section class='av_tab_section av_tab_section av-6nqy8-e898b277566c981c6ef6d80d4391f4e0'  itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='tab' role='tab' tabindex='0' data-fake-id='#tab-id-2' aria-controls='tab-id-2-content'  itemprop=\"headline\" >LED doesn\u2019t light up\/blinks<\/div><div id='tab-id-2-content' class='tab_content' aria-hidden=\"true\"><div class='tab_inner_content invers-color'  itemprop=\"text\" ><p><strong style=\"color: #ff0000; font-size: 18px;\"><em>*****<\/em><\/strong><\/p>\n<ul>\n<li><strong style=\"color: #ff0000; font-size: 18px;\"><em>Make sure the soldering iron you are using is ESD-safe.\u00a0 some iron tips may float at arbitrary voltages unless an additional grounding wire is used.\u00a0 you can easily kill chips when soldering if\u00a0 soldering iron is not grounded properly.<\/em><\/strong><\/li>\n<\/ul>\n<p><strong style=\"color: #ff0000; font-size: 18px;\"><em>*****\u00a0<\/em><\/strong><\/p>\n<ul>\n<li>\n<h4><span style=\"color: #ff0000;\"><strong><em>Pls take a few high resolution and in-focus photos of Flight Controller still installed and wired,\u00a0 then you can take it apart.\u00a0 These photos will be a huge help for troubleshooting if you decide to email us for service.<\/em><\/strong><\/span><\/h4>\n<\/li>\n<li>\n<h4><span style=\"color: #0000ff;\"><strong><span class=\"tran\" data-group=\"4_1\">Before<\/span> you start troubleshooting <span class=\"tran\" data-group=\"3_4\">steps<\/span>, <span class=\"tran\" data-group=\"5_5\">make sure<\/span> you have removed all wires connected to the FC board.<\/strong><\/span><\/h4>\n<\/li>\n<\/ul>\n<ul>\n<li>\n<h5><span style=\"color: #ff0000;\"><strong>LED doesn&#8217;t light up or weak light and MCU\/3.3V LDO chip heat up fast after connecting USB or battery.\u00a0 FC can&#8217;t connect to configurator.<\/strong><\/span><\/h5>\n<\/li>\n<\/ul>\n<ul>\n<li style=\"list-style-type: none;\">\n<ul>\n<li>Finger can&#8217;t touch MCU surface or LDO3.3V chip for more than 1 second, \u00a0Most likely MCU is dead, there is short circuit in core of MCU.<\/li>\n<li>\n<p class=\"src grammarSection\" data-group=\"1-1\"><strong><span style=\"color: #ff0000;\">The obvious symptom is short circuit or low resistance between 3V3 and G.<\/span><\/strong><\/p>\n<\/li>\n<li><span style=\"color: #0000ff;\">MCU health can be tested easily by connecting USB only.\u00a0 Wrong wiring on MCU I\/O or ESD from peripherals could damage MCU. \u00a0 so once the board was soldered or wired. \u00a0MCU death is not covered by warranty.<\/span><\/li>\n<li>If you have hot air work station,\u00a0 you might replace MCU.\u00a0 \u00a0Flashing it in DFU mode after replacing MCU.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<ul>\n<li>\n<h5>Red LED(3v3 indicator) doesn\u2019t light up or weak light when connecting FC USB to PC<\/h5>\n<ul>\n<li>Disconnect USB, then test the resistance\/continuity between 3v3 and G, 4v5 and G<\/li>\n<li>Resistance between 3v3 and G should be Kohm grade.<\/li>\n<li>If there is continuity between 3v3 and G\n<ul>\n<li><strong>Double check if there is solder ball\/splash on the capacitors\/MCU pins<\/strong><\/li>\n<li><strong>Unsolder\/Disconnect all peripherals from FC board, test it again.<\/strong><\/li>\n<\/ul>\n<\/li>\n<li>If there is continuity between\u00a04v5 and G\n<ul>\n<li>Unsolder\/Disconnect all peripherals from FC 4v5 rail, test it again.<\/li>\n<\/ul>\n<\/li>\n<li>If no continuity\n<ul>\n<li>Try another USB cable<\/li>\n<li>Check if there is dry joint on USB pins<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<ul>\n<li>\n<h5>Flight controller can power on via USB,\u00a0 but can not power on via battery.<\/h5>\n<ul>\n<li>Usually it is caused by short circuit on 5V rail or faulty 5V regulator.<\/li>\n<li><strong>Test the continuity\/resistance between 5V and G without any battery and USB connected.<\/strong><\/li>\n<\/ul>\n<ul>\n<li><strong>If you have wired some peripherals to the board,\u00a0<\/strong> <strong>Unsolder\/Disconnect all peripherals from 5V rail<\/strong>,\u00a0 Test the continuity again.<\/li>\n<li>If no continuity between 5V and G,\u00a0 \u00a0test the voltage on 5V and 4v5 pad while connecting battery only.\u00a0 If no 5V output,\u00a0 regulator chip could be dead.<\/li>\n<\/ul>\n<ul>\n<li style=\"list-style-type: none;\"><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<ul>\n<li style=\"list-style-type: none;\"><\/li>\n<\/ul>\n<\/div><\/div><\/section>\n<section class='av_tab_section av_tab_section av-2g97eo-9418d7d21f3b281812e259a967f0194a'  itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='tab' role='tab' tabindex='0' data-fake-id='#tab-id-3' aria-controls='tab-id-3-content'  itemprop=\"headline\" >FC hang when booting<\/div><div id='tab-id-3-content' class='tab_content' aria-hidden=\"true\"><div class='tab_inner_content invers-color'  itemprop=\"text\" ><ul>\n<li>Double check if FC is flashed with right Target.<\/li>\n<li>Reflash it with full chip erase selected.<\/li>\n<li>DO NOT try to use a diff or dump from other versions.<\/li>\n<li>In particular check devices on the I2C bus. Errors with that bus (magnetometer, barometer, AirSpeed) tend to really screw with the operation of the FC in a way.\n<ul>\n<li>check I2C devices wiring(SCL-SCL, SDA-SDA),\u00a0 and check if I2C devices are powered on when FC initialization.<\/li>\n<li>Try desoldering\/disconnecting I2C devices from FC board to see if FC can boot normal.<\/li>\n<li>Reflash FC with full chip erase selected,\u00a0 CLI &#8220;defaults&#8221; after reflashing, then reconfigure I2C devices in configurator.<\/li>\n<li>or set I2C speed in INAV configurator\n<ul>\n<li>Some I2C sensors are reported to work unreliably on default 400kHz speed. INav allows to reduce I2C clock rate to 200kHz and 100kHz to allow these picky sensors to function properly.<\/li>\n<li>If compass sensor is not recognized or hangs when setting, please try CLI command \u201cset i2c_speed = 200KHZ\u201d\u00a0 before reporting a bug.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/div><\/div><\/section>\n<section class='av_tab_section av_tab_section av-85hr28-870657f0d5ef2d7735445986228c3e9f'  itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='tab' role='tab' tabindex='0' data-fake-id='#tab-id-4' aria-controls='tab-id-4-content'  itemprop=\"headline\" >Red LED lights up, Blue and Green LED blink alternately three times<\/div><div id='tab-id-4-content' class='tab_content' aria-hidden=\"true\"><div class='tab_inner_content invers-color'  itemprop=\"text\" ><ul>\n<li>Gyro\/Acc can&#8217;t be detected when FC\u00a0initialization.<\/li>\n<li>Check if FC is flashed with right Target<\/li>\n<li>Check if there is solder ball\/splash on Gyro chip, or solder ball\/splash on capacitors nearby Gyro<\/li>\n<\/ul>\n<\/div><\/div><\/section>\n<section class='av_tab_section av_tab_section av-2j1q8g-970b6d6ddb1c4b777603c7be546aa5fd'  itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='tab' role='tab' tabindex='0' data-fake-id='#tab-id-5' aria-controls='tab-id-5-content'  itemprop=\"headline\" >Servos\/Motors don\u2019t work with INAV firmware<\/div><div id='tab-id-5-content' class='tab_content' aria-hidden=\"true\"><div class='tab_inner_content invers-color'  itemprop=\"text\" ><ul>\n<li>Make sure INav firmware version is compatible with configuration version,\u00a0 e.g. use configurator 2.5.x for firmware_2.5.x<\/li>\n<li>Check if motor and servo output is enabled in &#8220;configuration&#8221; tab.<\/li>\n<li>Check if motor and servo mixers are configured in &#8220;Mixer&#8221; tab.<\/li>\n<li>Don&#8217;t enable &#8220;External PWM servo driver&#8221;<\/li>\n<\/ul>\n<p>Servo<\/p>\n<ul>\n<li>WING series FC\n<ul>\n<li>Test the voltage between &#8220;Vx&#8221; and G when FC is powered via battery.<\/li>\n<li>If no voltage on Vx rail, disconnect\/desolder all servos from Vx rail, test it again.<\/li>\n<\/ul>\n<\/li>\n<li>Other series\n<ul>\n<li>Test the voltage on servos power source, e.g. 5V<\/li>\n<\/ul>\n<\/li>\n<li>There is a known issue that some 433\/900M transmitters\/receivers could\u00a0interfere servos.\u00a0 put them far from servos, or try 2.4G radio system.<\/li>\n<\/ul>\n<p>Motor<\/p>\n<ul>\n<li>check if ESC is powered on.<\/li>\n<li>check if ESC protocol selected is compatible with your ESC.<\/li>\n<li>check if ESC PWM range is calibrated if using PWM\/oneshot\/multishot protocol.<\/li>\n<li>check the Arming prevention flags and OSD warning when you try to arm FC.<\/li>\n<\/ul>\n<div id=\"gtx-trans\" style=\"position: absolute; left: 232px; top: 400px;\">\n<div class=\"gtx-trans-icon\"><\/div>\n<\/div>\n<\/div><\/div><\/section>\n<section class='av_tab_section av_tab_section av-3579nk-fc2b1fcb5c3ed505aa6ce92f7fd780b7'  itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='tab' role='tab' tabindex='0' data-fake-id='#tab-id-6' aria-controls='tab-id-6-content'  itemprop=\"headline\" >GPS not working<\/div><div id='tab-id-6-content' class='tab_content' aria-hidden=\"true\"><div class='tab_inner_content invers-color'  itemprop=\"text\" ><ul>\n<li><strong>GPS can work with any spare UART<\/strong><\/li>\n<li><\/li>\n<\/ul>\n<ul>\n<li>\n<h5>Red(inav)\/Gray(BF)\/ GPS icon at top of configurator\uff0cNo GPS(ArduPilot)<\/h5>\n<ul>\n<li>Check GPS wiring and cables continuity, GPS TX &#8211; FC RX, GPS RX &#8211; FC TX<\/li>\n<li>Check if GPS module is powered on.<\/li>\n<li>Check if GPS is configured on proper Uart in Ports Tab.<\/li>\n<li>Check GPS protocol in configuration tab, usually use UBLOX protocol for most of GPS modules.<\/li>\n<li>Try swapping protocol from ublox to NMEA, or from NMEA to ublox.<\/li>\n<\/ul>\n<\/li>\n<li>\n<h5>Blue(inav)\/Bright(BF) GPS icon at top of configurator, no satellites signal\uff0c No Fix(ArduPilot)<\/h5>\n<ul>\n<li>Put GPS nearby windows or outdoor.<\/li>\n<li>Try testing GPS and FC with USB power only,\u00a0 make sure other peripherals(VTX, Receiver, Camera,etc) are not powered on.<\/li>\n<li>\n<div><span style=\"color: #0000ff;\">DO NOT set any unnecessary GPS paramaters if you don&#8217;t know how they work.\u00a0 with ArduPilot, just need to set SERIALx_protocol = 5 on corresponding UART.\u00a0 don&#8217;t need to set any other GPS paramaters, leave all others by default.\u00a0 with INAV\/Betaflight, just need to configure GPS on on corresponding UART. enable &#8220;GPS&#8221; and &#8220;ublox protocol&#8221;. don&#8217;t need to set any baudrate. LESS IS MORE.<\/span><\/div>\n<\/li>\n<li><strong><span style=\"color: #ff0000;\">It is known that\u00a0<\/span><\/strong>HD cameras(Gopro, Split, Tarsier, DJI etc) could interfere GPS signal,\u00a0 If GPS can\u2019t get 3D fix after powering on for dozens of minutes. try turning off HD camera.<\/li>\n<li>There are reports that Frsky X8R could interfere GPS. If you are using X8R and GPS can\u2019t get 3D locked.\u00a0 power off X8R then test.<\/li>\n<\/ul>\n<\/li>\n<li>\n<h5>Tips<\/h5>\n<ul>\n<li>\n<div>UBlox NEO-M9N, MAX-M10S, SAM-M10Q series all don\u2019t have dataflash built in. \u00a0once GNSS is powered off and the supercapacitor run out. the settings will back to default.<\/div>\n<\/li>\n<li>\n<div>UBX protocol is bidirectional. \u00a0Flight controller firmware can change parameters in GNSS module via UBX protocol. You don\u2019t need to set GNSS module Baud and Frequency in u-center.<\/div>\n<\/li>\n<li><strong>Sometimes FC firmware command could also mess up the parameters in GPS module.\u00a0 If you are sure wiring and setup are all right. but flight controller can\u2019t detect the GNSS module or GNSS can&#8217;t receive any satellites after dozens minutes.\u00a0 Try connecting GNSS to USB-TTL module to computer, use U-center to revert GPS to default configuration,\u00a0 then check the GPS status in u-center.<\/strong><\/li>\n<li><strong>The M10Q-5883, SAM-M10Q, M10-L4-3100 provide the ability to reset the receiver.\u00a0 when powering on, bridging \u201cRST\u201d pad to Ground for at least 100 ms will trigger a cold start. RESET will delete all information and trigger a cold start.<\/strong><\/li>\n<\/ul>\n<\/li>\n<li>\n<h5>Revert GPS to default configuration<\/h5>\n<ol>\n<li>Install <a href=\"https:\/\/www.u-blox.com\/en\/product\/u-center\" target=\"_blank\" rel=\"noopener\">U-Center<\/a> software<\/li>\n<li>Attach your GPS to a USB-UART adapter(USB-TTL module, CP210x, FTDI, etc) and connect it to your computer.<\/li>\n<li>Launch U-Center software. Clicking the connect button and choosing the correct serial port and baudrate shall make the software connect with the GPS and displaying received data in the data view window contiuniously. If nothing appeared, check your connection and serial port parameters and try other baudrate.<\/li>\n<li>Open the configuration view by pressing F9.<\/li>\n<li>Navigate to UBX -&gt; CFG -&gt; CFG and select &#8220;Revert to default configuration&#8221; and click &#8220;Send&#8221; button located on the bottom.<\/li>\n<li><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-7241 size-full\" src=\"https:\/\/www.mateksys.com\/wp-content\/uploads\/2020\/07\/U-center_1.jpg\" alt=\"\" width=\"776\" height=\"495\" \/><\/li>\n<\/ol>\n<\/li>\n<li>\n<h5>PPS LED not working when GPS 3D fix<\/h5>\n<ul>\n<li><a href=\"https:\/\/www.u-blox.com\/sites\/default\/files\/GNSS-FW3.01_ReleaseNotes_%28UBX-16000319%29_Public.pdf\" target=\"_blank\" rel=\"noopener\">https:\/\/www.u-blox.com\/sites\/default\/files\/GNSS-FW3.01_ReleaseNotes_%28UBX-16000319%29_Public.pdf<\/a>,\u00a0 section 3.2.2<\/li>\n<li>Start with u-blox GNSS FW 3.01,\u00a0 timepulse is aligned with UTC time and that time is set valid only after leap second is downloaded. That could take up to 12.5 min. You can change timepulse configuration to GPS time(in ucenter, UBX-&gt;CFG-&gt;TP5-&gt;[1] GPS TIME) and then timepulse should be produced as soon as valid fix is present.<\/li>\n<li>1PPS output or not doesn&#8217;t affect GPS 3D fix performance.\u00a0 \u00a0if GPS can receive enough satellites and has good 3D fix. Your Quad\/Plane are good to go.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/div><\/div><\/section>\n<section class='av_tab_section av_tab_section av-3axvxc-05bada0339bfb35b19b4a7fefa840147'  itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='tab' role='tab' tabindex='0' data-fake-id='#tab-id-7' aria-controls='tab-id-7-content'  itemprop=\"headline\" >I2C errors<\/div><div id='tab-id-7-content' class='tab_content' aria-hidden=\"true\"><div class='tab_inner_content invers-color'  itemprop=\"text\" ><ul>\n<li>\n<h4>If the I2C errors doesn&#8217;t keep going up after boot. that is normal.\u00a0 \u00a0The errors occur during FC initialisation before the I2C speeds are all set up right.<\/h4>\n<\/li>\n<\/ul>\n<h4>I2C bus speed selection<\/h4>\n<ul>\n<li>Some I2C sensors are reported to work unreliably on default 400kHz speed. INav allows to reduce I2C clock rate to 200kHz and 100kHz to allow these picky sensors to function properly.<\/li>\n<li>If compass sensor is not recognized or hangs when setting, please try CLI command \u201cset i2c_speed = 200KHZ\u201d\u00a0 before reporting a bug.<\/li>\n<\/ul>\n<\/div><\/div><\/section>\n<section class='av_tab_section av_tab_section av-4f704w-00fd2abf783e3361c6ed8865d2310d56'  itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='tab' role='tab' tabindex='0' data-fake-id='#tab-id-8' aria-controls='tab-id-8-content'  itemprop=\"headline\" >Flight controller Power Circuit<\/div><div id='tab-id-8-content' class='tab_content' aria-hidden=\"true\"><div class='tab_inner_content invers-color'  itemprop=\"text\" ><p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-6106\" src=\"https:\/\/www.mateksys.com\/wp-content\/uploads\/2019\/07\/FC_Power_circuit.jpg\" alt=\"\" width=\"1031\" height=\"864\" srcset=\"https:\/\/www.mateksys.com\/wp-content\/uploads\/2019\/07\/FC_Power_circuit.jpg 1031w, https:\/\/www.mateksys.com\/wp-content\/uploads\/2019\/07\/FC_Power_circuit-768x644.jpg 768w, https:\/\/www.mateksys.com\/wp-content\/uploads\/2019\/07\/FC_Power_circuit-1030x863.jpg 1030w, https:\/\/www.mateksys.com\/wp-content\/uploads\/2019\/07\/FC_Power_circuit-705x591.jpg 705w, https:\/\/www.mateksys.com\/wp-content\/uploads\/2019\/07\/FC_Power_circuit-450x377.jpg 450w\" sizes=\"auto, (max-width: 1031px) 100vw, 1031px\" \/><\/p>\n<div  class='hr av-4dgf1s-a49239d750bf2f1759dafc36f3ba8341 hr-full  avia-builder-el-3  avia-builder-el-no-sibling  hr-no-shadow'><span class='hr-inner '><span class=\"hr-inner-style\"><\/span><\/span><\/div>\n<p><strong>*** F405-STD, F722-STD &amp; F405-mini have no 5V regulator builtin.\u00a0 They need to be powered up via external 5V source. VCC pad on these FC are for battery voltage detection only.<\/strong><\/p>\n<\/div><\/div><\/section>\n<section class='av_tab_section av_tab_section av-6xlw0-4deab4778f31457edc68accbae2f5a40'  itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='tab' role='tab' tabindex='0' data-fake-id='#tab-id-9' aria-controls='tab-id-9-content'  itemprop=\"headline\" >OSD flickering<\/div><div id='tab-id-9-content' class='tab_content' aria-hidden=\"true\"><div class='tab_inner_content invers-color'  itemprop=\"text\" ><p>Need low ESR capacitor on your ESC to absorb the BEMF switching noise.<\/p>\n<p>4in1 ESC,\u00a0 one 1000uF<\/p>\n<p>4x individual ESC,\u00a0 220uF~470uF per ESC<\/p>\n<div><span style=\"color: #000000;\">Low ESR capcaitors, e.g.<\/span><\/div>\n<ul>\n<li>Rubycon:\u00a0ZLH,\u00a0\u00a0ZLG,\u00a0\u00a0ZLQ\u00a0<wbr \/>series<\/li>\n<li>Panasonic:\u00a0FM,\u00a0FR\u00a0series<\/li>\n<li>Nippon Chemi-con: KZE, KZH, KZM series<\/li>\n<li>Nichicon:\u00a0UHV\u00a0series<\/li>\n<\/ul>\n<\/div><\/div><\/section>\n<section class='av_tab_section av_tab_section av-2e2rc0-b2f088de98b9f4f488d017922445f94b'  itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='tab' role='tab' tabindex='0' data-fake-id='#tab-id-10' aria-controls='tab-id-10-content'  itemprop=\"headline\" >Conformal coating<\/div><div id='tab-id-10-content' class='tab_content' aria-hidden=\"true\"><div class='tab_inner_content invers-color'  itemprop=\"text\" ><ul>\n<li>\n<h5><span style=\"color: #ff0000;\">We have got a few reports that coating caused short circuit between power rails, and resistance changing between MCU\/chips pins.<\/span><\/h5>\n<\/li>\n<li>\n<h5>If you are not sure of its properties, conformal coating is <span style=\"color: #ff0000;\">NOT recommended<\/span> before you confirm every function works well.<\/h5>\n<\/li>\n<li>\n<h5><strong>Once the board is coated,\u00a0 no way to troubleshoot<\/strong><\/h5>\n<\/li>\n<\/ul>\n<\/div><\/div><\/section>\n<section class='av_tab_section av_tab_section av-7qr9s-81b68118f0e8cdf339b7769b77de37a3'  itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='tab' role='tab' tabindex='0' data-fake-id='#tab-id-11' aria-controls='tab-id-11-content'  itemprop=\"headline\" >DJI Air unit OSD<\/div><div id='tab-id-11-content' class='tab_content' aria-hidden=\"true\"><div class='tab_inner_content invers-color'  itemprop=\"text\" ><h5><span style=\"color: #ff0000;\"><strong>DJI Air unit\/Vista can work with ANYYYYYYY spare UART\/softserial of ANYYYYYY flight controllers supported by Betaflight\/INAV\/ArduPilot firmware<\/strong><\/span><\/h5>\n<hr \/>\n<ul>\n<li><strong>Power &#8212;&gt; Power source according to air unit voltage spec.<\/strong><\/li>\n<li><strong>GND &#8212;&gt; FC GND<\/strong><\/li>\n<li><strong>UART RX &#8212;&gt; FC spare UART_TX\/Softserial_Tx<\/strong><\/li>\n<li><strong>UART TX &#8212;&gt; FC spare UART_RX\/Softserial_Rx<\/strong><\/li>\n<li>GND &#8212;&gt; FC GND<\/li>\n<li>DJI HDL &#8212;&gt;FC any spare UART_RX(F7,H7),\u00a0 \u00a0FC SBUS pad (F4)<\/li>\n<li>If not using DJI radio, no need to connect 5th GND and 6th DJI HDL to Flight Controller.<\/li>\n<\/ul>\n<hr \/>\n<ul>\n<li>Betaflight: enable MSP on corresponding UART<\/li>\n<li><\/li>\n<li>INAV:\u00a0 <a href=\"https:\/\/www.youtube.com\/watch?v=elq6AF5gdXE\" target=\"_blank\" rel=\"noopener\">Youtube_How to set up HD FPV systems in INAV<\/a><\/li>\n<li><\/li>\n<\/ul>\n<ul>\n<li>ArduPilot: check out the wiki for settings. <a href=\"https:\/\/ardupilot.org\/plane\/docs\/common-msp-osd-overview.html\" target=\"_blank\" rel=\"noopener\">https:\/\/ardupilot.org\/plane\/docs\/common-msp-osd-overview.html<\/a><\/li>\n<li>SERIALn_BAUD = 115,\u00a0 SERIALn_OPTIONS = 0<\/li>\n<li>DJI Air Unit old versions:\u00a0 OSD_TYPE = 3,\u00a0\u00a0SERIALn_PROTOCOL = 33,\u00a0 \u00a0MSP_OPTIONS = 0<\/li>\n<li>DJI Air Unit O3:\u00a0 OSD_TYPE = 5,\u00a0 SERIALn_PROTOCOL = 42,\u00a0 \u00a0MSP_OPTIONS = 4<\/li>\n<\/ul>\n<\/div><\/div><\/section>\n<section class='av_tab_section av_tab_section av-35mhhs-72608f576104b5aa6ffa3eb0768214cd'  itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='tab' role='tab' tabindex='0' data-fake-id='#tab-id-12' aria-controls='tab-id-12-content'  itemprop=\"headline\" >Current readout fluctuating<\/div><div id='tab-id-12-content' class='tab_content' aria-hidden=\"true\"><div class='tab_inner_content invers-color'  itemprop=\"text\" ><p>We are using a high precision current amplifier on<strong> H743-WLite \/ H743-WING \/F405-WTE\/F405-VTOL \/ F722-WING \/ F722-WPX\/ F405-WSE\/ F765-WING\/F765-WSE\/<\/strong><\/p>\n<p>This amplifier offers precision accuracy specifications of <strong>2\u03bcV<\/strong> Input Offset Voltage and gain error of <strong>0.05%<\/strong>.\u00a0 (The most common current amplifier is<strong> TI INA139\/INA169<\/strong> which has Input Offset Voltage <strong>200\u03bcV<\/strong> &amp; gain error of <strong>0.5%<\/strong>.\u00a0 Usually INA139 can&#8217;t provide a valid reading when the current is less than 1A at 100A current sensor range)<\/p>\n<p><strong>This high precision amplifier is sensitive to ESC noise. make sure ESC is filtered well.<\/strong><\/p>\n<ul>\n<li>If you are using Blheli32 ESC,\u00a0 setting ESC PWM to 48K in BLHeli32Suite can reduce the ESC noise.\u00a0 higher ESC PWM rate, lower noise.<\/li>\n<li>Sometimes need to add a 330~680uF <strong>low ESR<\/strong> capacitor on the ESC power pads of Flight controller to absorb the switching noise.<\/li>\n<\/ul>\n<div><span style=\"color: #000000;\">Low ESR capcaitors, e.g.<\/span><\/div>\n<ul>\n<li>Rubycon:\u00a0ZLH,\u00a0\u00a0ZLG,\u00a0\u00a0ZLQ\u00a0<wbr \/>series<\/li>\n<li>Panasonic:\u00a0FM,\u00a0FR\u00a0series<\/li>\n<li>Nippon Chemi-con: KZE, KZH, KZM series<\/li>\n<li>Nichicon:\u00a0UHV\u00a0series<\/li>\n<\/ul>\n<\/div><\/div><\/section>\n<section class='av_tab_section av_tab_section av-2lpblc-396dcd94583ddf922cdbf8364155aefd'  itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='tab' role='tab' tabindex='0' data-fake-id='#tab-id-13' aria-controls='tab-id-13-content'  itemprop=\"headline\" >Blackbox\/SD card tips<\/div><div id='tab-id-13-content' class='tab_content' aria-hidden=\"true\"><div class='tab_inner_content invers-color'  itemprop=\"text\" ><ul>\n<li>There are 2 types of Blackbox logging device, SD card and on-board flash chip(e.g. 16M, 32M).<\/li>\n<li>The majority of Flight controllers use just one storage media.\u00a0 If the FC integrates SD card socket, and doesn&#8217;t integrate NOR\/NAND flash chip.\u00a0 &#8220;No dataflash chip found&#8221; will show at the top right corner of INAV\/BF configurator.<\/li>\n<\/ul>\n<ul>\n<li>SD card must be formatted in FAT32. (not exFAT or NTFS).<\/li>\n<li>Once formatted in the FAT32 format only 4 GB will be usable for the Blackbox usage even if the SD card capacity is 16GB, 64GB, 128GB etc.<\/li>\n<li>\n<div>Plug SD into FC, \u00a0\u00a0then connect FC to USB only (no battery connected),\u00a0 Open Blackbox Tab, waiting Filesystem initialization.<\/div>\n<\/li>\n<li>Some SD cards have compatibility issue. you might need to try more SD cards sometimes.<\/li>\n<li>SAMSUNG microSD is recommended.<\/li>\n<\/ul>\n<\/div><\/div><\/section>\n<section class='av_tab_section av_tab_section av-2gk4xc-11e301b303e6ac1857601ff42866bc7d'  itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='tab' role='tab' tabindex='0' data-fake-id='#tab-id-14' aria-controls='tab-id-14-content'  itemprop=\"headline\" >FC USB break off<\/div><div id='tab-id-14-content' class='tab_content' aria-hidden=\"true\"><div class='tab_inner_content invers-color'  itemprop=\"text\" ><ul>\n<li><a href=\"https:\/\/www.st.com\/en\/development-tools\/stm32cubeprog.html\" target=\"_blank\" rel=\"noopener noreferrer\">https:\/\/www.st.com\/en\/development-tools\/stm32cubeprog.html<\/a><\/li>\n<li>You may download Windows version from here\u00a0\u00a0<a href=\"https:\/\/www.mateksys.com\/downloads\/fc\/en.stm32cubeprog_v2-3-0.zip\" target=\"_blank\" rel=\"noopener noreferrer\">en.stm32cubeprog_v2-3-0.zip<\/a><\/li>\n<li>Flashing via USB-TTL is compatible with INAV and ArduPilot,\u00a0 is not compatible with Betaflight because BF don&#8217;t have MSP enabled on UART1 by default.<\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-8980\" src=\"https:\/\/www.mateksys.com\/wp-content\/uploads\/2019\/07\/FC_USB_FIX.jpg\" alt=\"\" width=\"1081\" height=\"2794\" \/><\/p>\n<\/div><\/div><\/section>\n<section class='av_tab_section av_tab_section av-1xzeuo-648708fa7d1c4694f3b214f0cbf25679'  itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='tab' role='tab' tabindex='0' data-fake-id='#tab-id-15' aria-controls='tab-id-15-content'  itemprop=\"headline\" >Regulator chips burnt<\/div><div id='tab-id-15-content' class='tab_content' aria-hidden=\"true\"><div class='tab_inner_content invers-color'  itemprop=\"text\" ><p>The regulator chips damage usually happens at the moment when the battery is plugged.<\/p>\n<p>If we check the voltage surge on oscilloscope,\u00a0 the transient voltage occurs within 50us when the battery is connected.\u00a0 sometimes the transient voltage can be twice of the battery voltage.<\/p>\n<p>If you are using 6S LiPo or higher, We strongly recommend adding TVS diodes.<\/p>\n<p>What is a TVS Diode and How Does it Work?<\/p>\n<ul>\n<li>The Transient Voltage Suppression diode (TVS) is a component that is commonly used for transient protection. (Not to be confused with zener diode or schottky diode.) It consists of a p-n semiconductor junction that becomes conductive during a transient voltage spike. In normal circumstances, it appears as an open circuit despite a small leakage current.<\/li>\n<li>When the voltage on the transient voltage suppressor rises across its threshold voltage(Minimum Breakdown Voltage), the avalanche effect of the semiconductor causes the p-n junction to become a low-impedance path that channels away the excessive current. The response time of the TVS diode is extremely fast, often expressed in picoseconds.<\/li>\n<li>Minimum Breakdown Voltage to\u00a0 Maximum Clamping Voltage &#8211; The clamping voltage is the voltage limited by the TVS diode in the event of a transient within the limit of the specified peak current.\u00a0 for 6S LiPo,\u00a0 28V Minimum Breakdown Voltage is is recommended (e.g. SMBJ26A, SBMJ28A).\u00a0 SMBJ33A for 8S LiPO.<\/li>\n<li>The placement of the TVS diode is also important. It is a good practice to place TVS diodes as close to the power source as possible.<\/li>\n<li><a href=\"https:\/\/en.wikipedia.org\/wiki\/Transient-voltage-suppression_diode\" target=\"_blank\" rel=\"noopener\">en.wikipedia.org\/wiki\/Transient-voltage-suppression_diode<\/a><\/li>\n<li><a class=\"external text\" href=\"https:\/\/www.mouser.com\/pdfDocs\/semtech-si96-01.pdf\" rel=\"nofollow\"><i>What are TVS diodes<\/i>, Semtech Application Note SI96-01<\/a><\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-9096\" src=\"https:\/\/www.mateksys.com\/wp-content\/uploads\/2019\/07\/voltage_surge.jpg\" alt=\"\" width=\"1200\" height=\"1393\" \/><\/p>\n<\/div><\/div><\/section>\n<section class='av_tab_section av_tab_section av-24dtls-be692b1fed08920b4234a3071c5d775b'  itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='tab' role='tab' tabindex='0' data-fake-id='#tab-id-16' aria-controls='tab-id-16-content'  itemprop=\"headline\" >INAV \"Alt\" floating<\/div><div id='tab-id-16-content' class='tab_content' aria-hidden=\"true\"><div class='tab_inner_content invers-color'  itemprop=\"text\" ><div>\n<ul>\n<li>open INAV configurator &#8212; sensors tab.<\/li>\n<li>check if &#8220;Baro&#8221; readout is normal. \u00a0&#8220;Baro&#8221; is the raw readout of Barometer sensor. If \u201cBaro\u201d responds correctly to height changes. Barometer sensor is working fine.<\/li>\n<li>OSD and navigation related features use &#8220;Alt&#8221; readout.\u00a0 &#8220;Alt&#8221; is the Altitude computed by the all AHRS sensors, \u00a0ARHS is related to barometer\/gyro\/acc\/compass\/GPS and PID settings. \u00a0If one of these is not set\/calibrate right. &#8220;Alt&#8221; readout will be all over the place.<\/li>\n<li>e.g. if the acc is not calibrated. you will not get right &#8220;Alt&#8221; readout.\u00a0 It&#8217;s easy to verify, \u00a0Flip the FC 180 degree, then check the Baro and Alt readout. &#8220;Baro&#8221; should be stable, \u00a0&#8220;Alt&#8221; will climb and descend when flipping FC.<\/li>\n<li>You may check out this video.\u00a0 \u00a0<a href=\"https:\/\/www.youtube.com\/watch?v=aE5oVbBtlig\" target=\"_blank\" rel=\"noopener\">Why INAV climbs rapidly in Altitude Hold mode?<\/a>\u00a0 by <a class=\"yt-simple-endpoint style-scope yt-formatted-string\" dir=\"auto\" spellcheck=\"false\" href=\"https:\/\/www.youtube.com\/channel\/UCmX3OXToMBKTppgRskDzpsw\">Pawe\u0142 Spychalski<\/a><\/li>\n<\/ul>\n<\/div>\n<div><\/div>\n<div><\/div>\n<\/div><\/div><\/section>\n<section class='av_tab_section av_tab_section av-32t3sw-dc86a5e4b4eca4220d1606b5db5a8756'  itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='tab' role='tab' tabindex='0' data-fake-id='#tab-id-17' aria-controls='tab-id-17-content'  itemprop=\"headline\" >ELRS Failsafe at 500Hz in ArduPilot<\/div><div id='tab-id-17-content' class='tab_content' aria-hidden=\"true\"><div class='tab_inner_content invers-color'  itemprop=\"text\" ><p><a href=\"https:\/\/github.com\/ExpressLRS\/ExpressLRS\/issues\/1773\">https:\/\/github.com\/ExpressLRS\/ExpressLRS\/issues\/1773<\/a><\/p>\n<p><a href=\"https:\/\/github.com\/ArduPilot\/ardupilot\/pull\/24170\">https:\/\/github.com\/ArduPilot\/ardupilot\/pull\/24170<\/a><\/p>\n<p><a href=\"https:\/\/github.com\/ArduPilot\/ardupilot\/issues\/23853\">https:\/\/github.com\/ArduPilot\/ardupilot\/issues\/23853<\/a><\/p>\n<\/div><\/div><\/section>\n<section class='av_tab_section av_tab_section av-lu3msxlk-9ff890da6afdf9c6055628f17d523aa0'  itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='tab' role='tab' tabindex='0' data-fake-id='#tab-id-18' aria-controls='tab-id-18-content'  itemprop=\"headline\" >Power monitor\/Current sensor series<\/div><div id='tab-id-18-content' class='tab_content' aria-hidden=\"true\"><div class='tab_inner_content invers-color'  itemprop=\"text\" ><table width=\"631\">\n<tbody>\n<tr>\n<td width=\"112\">SKU<\/td>\n<td width=\"147\">I2C-INA-BM<\/td>\n<td width=\"147\">CAN-L4-BM<\/td>\n<td width=\"225\">HCS-150A<\/td>\n<\/tr>\n<tr>\n<td>Type<\/td>\n<td>Shunt resistor<\/td>\n<td>Shunt resistor<\/td>\n<td>Hall effect<\/td>\n<\/tr>\n<tr>\n<td>Interface<\/td>\n<td>I2C<\/td>\n<td>CAN<\/td>\n<td>Analog\uff0cADC<\/td>\n<\/tr>\n<tr>\n<td>Voltage Range<\/td>\n<td>\u00a00~85V<\/td>\n<td>\u00a00~85V<\/td>\n<td>0~69V<\/td>\n<\/tr>\n<tr>\n<td>Current Range<\/td>\n<td>0~204.8A<\/td>\n<td>0~204.8A<\/td>\n<td>0~150A<\/td>\n<\/tr>\n<tr>\n<td>Compatible<\/td>\n<td>ArduPilot<\/td>\n<td>ArduPilot<\/td>\n<td width=\"225\">ArduPilot<br \/>\nINAV<br \/>\nBetaflight<\/td>\n<\/tr>\n<tr>\n<td>Features<\/td>\n<td>Digital, High precise<\/td>\n<td>Digital, High precise<\/td>\n<td width=\"225\">No power loss and heat<br \/>\non current sensor components<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div><\/div><\/section>\n<\/div>\n<div  class='hr av-2uujg0-6a68e943a49e8124b50cba4d3266140a hr-short  avia-builder-el-4  el_after_av_tab_container  avia-builder-el-last  hr-center'><span class='hr-inner '><span class=\"hr-inner-style\"><\/span><\/span><\/div>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":true,"template":"","format":"standard","meta":{"footnotes":""},"categories":[34],"tags":[],"class_list":["post-5712","post","type-post","status-publish","format-standard","hentry","category-technology"],"_links":{"self":[{"href":"https:\/\/www.mateksys.com\/index.php?rest_route=\/wp\/v2\/posts\/5712","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.mateksys.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.mateksys.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.mateksys.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.mateksys.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=5712"}],"version-history":[{"count":2,"href":"https:\/\/www.mateksys.com\/index.php?rest_route=\/wp\/v2\/posts\/5712\/revisions"}],"predecessor-version":[{"id":13011,"href":"https:\/\/www.mateksys.com\/index.php?rest_route=\/wp\/v2\/posts\/5712\/revisions\/13011"}],"wp:attachment":[{"href":"https:\/\/www.mateksys.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=5712"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.mateksys.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=5712"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.mateksys.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=5712"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}