Unbricking Xiaomi Yi action camera

Yi Action Camera

Yi Action Camera

Two days ago I received my Xiaomi Yi Action Camera bought on eBay. Official app told me that there were the new firmware for my cam. After update my camera become dead.

Тег «Далее»

Ошибка «Could not stop Cortex-M device»

В моем случае подобная ошибка возникла на плате собственного изготовления из-за того, что пин BOOT0 в STM32F103RBT6 был повешен через резистор на VDD. 
И, как я понимаю, st-link писал код во флеш-память, а контроллер в неё не переходил из-за логической единицы на BOOT0.

Проблема решилась после соединения BOOT0 и GND через резистор.


I had this error because of the connection between BOOT0 and VCC. Resolution is simple: connect BOOT0 to GND.


Autocomplete in PyDev does not work after «import wx»

When you import wx libraries in python, autocomplete do not work. PyDev shows a lot of errors «Undefined variable from import: SOMETHING». But execution works good.

Снимок экрана 2014-02-04 в 23.35.42 Снимок экрана 2014-02-04 в 23.42.09

You have to add one simple line after «import wx».

import wx


How to use sprintf function in stm32f4xx firmware

Sometimes you need to implement pretty output to USART. This task can be solved in two ways:

  • Write your own converters from int or double to char*
  • Use sprintf and printf

Second way is better. I will use sprintf(str, ...) and write simple loop that will send str byte-by-byte to USART.

I use mac os x + eclipse + arm-none-eabi + openocd + stm32f4discovery.
Let’s start implementing this.
Тег «Далее»

Error with «kpathsea: Running mktexmf»

I installed BasicTex.pkg on Mac Os X, and tried to make PDF from IPython Notebook. But suddenly received an error:

kpathsea: Running mktexmf $NAME$
! I can't find file `$NAME$'.

This can be fixed with installing font packages from TeX Live Utility. This packages are included neither in BasicTeX.pkg nor in mactex-additions.pkg. But they are required for generating pdf.
It can be fixed by installing packages with summary «URW «Base 35″ font pack for LaTeX.»



After installation this errors would not appear again, i hope🙂

Рубрики:Mac OS X Метки: , , , ,

arm-none-eabi-gdb — Segmentation fault: 11 — b 2

UPD 14.10.13: This is a bug of GDB. It is already known and fixed.

Terry Guo: The gdb in this release has some problem to decode DWARF debug information generated by -g3 option. For the time being, please recompile your project with -g or -g2 to work around this issue.


I am trying to program stm32f303vct6 core on stm32f3discovery board via Eclipse+arm-none-eabi-gdb+openOCD. Source for this stm32 can be built with no errors. I use GNU Tools for ARM Embedded Processors. Also it can be uploaded to MCU. But there are some troubles with debugging: gdb can’t read symbols from the firmware. This means that there will be no breakpoints in code. It is awful.

No symbol file

No symbol file

Тег «Далее»

PyDev + Matplotlib + bring to front

Обычно окно с графиком pyplot при работе в Eclipse+Pydev оказывается под средой разработки, а это не очень удобно. 

Чтобы это окно оказалось поверх Eclipse, необходимо в самое начало файла с исходным кодом добавить следующие две строчки:

import matplotlib


When you are using Matplotlib with PyDev window with plot is shown under the PyDev window. If you would like to bring in to front, you should ass two line to the very beginning of your python code:
import matplotlib


After that Pyplot window will be shown above your eclipse window.

Рубрики:1 Метки: , , ,