From 0453764be3fa56f1fcbb9e9ca3eec5026e62ed51 Mon Sep 17 00:00:00 2001 From: Michael Ingraham <34340210+meingraham@users.noreply.github.com> Date: Tue, 1 Oct 2019 11:45:49 -0400 Subject: [PATCH] 74880 boot baud rate --- FAQ.md | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/FAQ.md b/FAQ.md index a6932145..03127788 100644 --- a/FAQ.md +++ b/FAQ.md @@ -47,21 +47,25 @@ Be sure to press the button correctly, you must "feel" a click. If your on-device button doesn't allow you to enter flash mode or there is no GPIO0 broken out to the PCB, you can always bridge GND to GPIO0 pin directly on the chip. Search on the Internet for your chip's pinouts and use [the tutorial](Hardware-Preparation#bringing-the-module-in-flash-mode). Be sure to keep GPIO0 grounded long enough (3-5 seconds) before disconnecting to ensure the chip has booted completely into programming mode. On devices that do not provide a GPIO0 connected button, it may be easier to leave the wired bridge in place throughout the entire flashing process (erase & upload). Doing so will not create any problems for flashing the device. After the firmware is uploaded successfully, remove the bridge. This allows the device to boot normally. ### Flashing issues -Double check if you wired the device the serial-to-USB adapter correctly. Almost every device needs RX and TX pins switched to TX and RX. See [Hardware Preparation](Hardware-preparation) for more. +- Double check if you wired the device the serial-to-USB adapter correctly. Almost every device needs RX and TX pins switched to TX and RX. See [Hardware Preparation](Hardware-preparation) for more. -Another common problem are the jumper cables used. Try another cable if you keep getting connection errors or check the cables for connectivity. Most of them are made cheaply and it happens quite often that those cables do not offer a good connection because of bad crimping or broken copper lines in them. +- Another common problem are the jumper cables used. Try another cable if you keep getting connection errors or check the cables for connectivity. Most of them are made cheaply and it happens quite often that those cables do not offer a good connection because of bad crimping or broken copper lines in them. -Be sure to use a **USB Data Cable** and not a cheap loading cable for mobile phones for connecting the serial-to-USB adapter to your computer. If you are unsure, just try another USB cable. Data USB cables are often thicker than the normal loading cables (and more expensive). +- Be sure to use a **USB Data Cable** and not a cheap loading cable for mobile phones for connecting the serial-to-USB adapter to your computer. If you are unsure, just try another USB cable. Data USB cables are often thicker than the normal loading cables (and more expensive). -Another problem can be the difficulties in getting the ESP chip into [programming mode](#cannot-enter-flash-mode) when it boots. +- Another problem can be the difficulties in getting the ESP chip into [programming mode](#cannot-enter-flash-mode) when it boots. -If the flash still fails or the progress interrupts, it could be that your computer or serial-to-USB adapter doesn't provide enough power to the device. Try another computer or use an external power supply (3.3V one). +- If the flash still fails or the progress interrupts, it could be that your computer or serial-to-USB adapter doesn't provide enough power to the device. Try another computer or use an external power supply (3.3V one). -Use the correct serial-to-USB adapter driver. Check the model of your adapter chip and get the correct driver. +- Use the correct serial-to-USB adapter driver. Check the model of your adapter chip and get the correct driver. -If the flash completes successfully, but you get a hash mismatch (esptool.py error message `A fatal error occurred: MD5 of file does not match data in flash!` ensure that your 3.3v current is sufficient. Workarounds include using a dedicated _bread board power supply_ or using the 3.3v output of an additional microcontroller. If using an additional power supply to power the device, be sure to use a common ground for the power supply, the device to be flashed and the serial-to-USB adapter. +- If the flash completes successfully, but you get a hash mismatch (esptool.py error message `A fatal error occurred: MD5 of file does not match data in flash!`) ensure that your 3.3v current is sufficient. Workarounds include using a dedicated _bread board power supply_ or using the 3.3v output of an additional microcontroller. If using an additional power supply to power the device, be sure to use a common ground for the power supply, the device to be flashed and the serial-to-USB adapter. -If esptool.py stops at "Uploading stub...", use --no-stub +- If esptool.py stops at "Uploading stub...", use --no-stub + +- If the flash fails or the device does not operate as expected, try using the default ESP82xx boot ROM baud rate - `74880`. This is the baud rate the ESP82xx is set to by default when it boots into programming mode. This baud rate is a selection option in [NodeMCU PyFlasher](Flashing#nodemcu-pyflasher). It can be specified as a command line option in [esptool.py](Flashing#esptoolpy) (`-b`) and [esptool.exe](Flashing#esptool-executable) (`-cb`). + + You may also want to select a serial monitor/terminal capable of setting this "unusual" baud rate. In Termite, type this value (`74880`) in the baud rate selection text box when configuring the port. Having the option to specify this unusual baud rate will allow you to view the [ESP8266 boot ROM log](https://github.com/espressif/esptool/wiki/ESP8266-Boot-ROM-Log) while the device is booting. ### Device is hot to the touch Remember - **NEVER EVER FLASH WITH 5V!**?