From 1e07be4db45092f60896652166ab58ffb6efd455 Mon Sep 17 00:00:00 2001 From: Kevin O'Connor Date: Tue, 9 Oct 2018 11:15:22 -0400 Subject: [PATCH] docs: Add a "Lost communication with MCU" section to the FAQ Signed-off-by: Kevin O'Connor --- docs/FAQ.md | 31 +++++++++++++++++++++++++++---- 1 file changed, 27 insertions(+), 4 deletions(-) diff --git a/docs/FAQ.md b/docs/FAQ.md index 135e5508..f54d3f41 100644 --- a/docs/FAQ.md +++ b/docs/FAQ.md @@ -12,10 +12,11 @@ Frequently asked questions 9. [Why is the Z position_endstop set to 0.5 in the default configs?](#why-is-the-z-position_endstop-set-to-05-in-the-default-configs) 10. [I converted my config from Marlin and the X/Y axes work fine, but I just get a screeching noise when homing the Z axis](#i-converted-my-config-from-marlin-and-the-xy-axes-work-fine-but-i-just-get-a-screeching-noise-when-homing-the-z-axis) 11. [My TMC motor driver turns off in the middle of a print](#my-tmc-motor-driver-turns-off-in-the-middle-of-a-print) -12. [When I set "restart_method=command" my AVR device just hangs on a restart](#when-i-set-restart_methodcommand-my-avr-device-just-hangs-on-a-restart) -13. [Will the heaters be left on if the Raspberry Pi crashes?](#will-the-heaters-be-left-on-if-the-raspberry-pi-crashes) -14. [How do I convert a Marlin pin number to a Klipper pin name?](#how-do-i-convert-a-marlin-pin-number-to-a-klipper-pin-name) -15. [How do I upgrade to the latest software?](#how-do-i-upgrade-to-the-latest-software) +12. [I keep getting random "Lost communication with MCU" errors](#i-keep-getting-random-lost-communication-with-mcu-errors) +13. [When I set "restart_method=command" my AVR device just hangs on a restart](#when-i-set-restart_methodcommand-my-avr-device-just-hangs-on-a-restart) +14. [Will the heaters be left on if the Raspberry Pi crashes?](#will-the-heaters-be-left-on-if-the-raspberry-pi-crashes) +15. [How do I convert a Marlin pin number to a Klipper pin name?](#how-do-i-convert-a-marlin-pin-number-to-a-klipper-pin-name) +16. [How do I upgrade to the latest software?](#how-do-i-upgrade-to-the-latest-software) ### How can I donate to the project? @@ -225,6 +226,28 @@ experience this problem during homing, consider using a slower homing speed. If you experience this problem in the middle of a print, consider using a lower square_corner_velocity setting. +### I keep getting random "Lost communication with MCU" errors + +This is commonly caused by hardware errors on the USB connection +between the host machine and the micro-controller. Things to look for: +- Use a good quality USB cable between the host machine and + micro-controller. Make sure the plugs are secure. +- If using a Raspberry Pi, use a good quality power supply for the + Raspberry Pi and use a good quality USB cable to connect that power + supply to the Pi. +- Make sure the printer's power supply is not being overloaded. (Power + fluctuations to the micro-controller's USB chip may result in resets + of that chip.) +- There have been reports of high USB noise when both the printer's + power supply and the host's 5V power supply are mixed. (If you find + that the micro-controller powers on when either the printer's power + supply is on or the USB cable is plugged in, then it indicates the + 5V power supplies are being mixed.) It may help to configure the + micro-controller to use power from only one source. (Alternatively, + if the micro-controller board can not configure its power source, + one may modify a USB cable so that it does not carry 5V power + between the host and micro-controller.) + ### When I set "restart_method=command" my AVR device just hangs on a restart Some old versions of the AVR bootloader have a known bug in watchdog