A quick dive in to ebay CJMCU-407 board with STM32F407VG

I recently came across a small board with stm32f407vg with all necessary components to use in DIY projects. In this post i would like to share some of the details esp , the pin connections which will be useful for others.  I found this board useful in some of my SDR (software defined radio ) projects and some audio projects (using DSP)


This board is shown in the figure below and can be easily spotted on ebay, taobao and other sites

CJMCU407 with stm32f4

  A schematic found on tao bao is shown below

Schematic cjmc (click to enlarge)

It is a useful board and can be easily programmed with an stlink or comaptible  programmers (https://www.riyas.org/2017/02/quickly-getting-started-with-stm32f4xx.html )

PIN CONNECTIONS FOR CJMCU407

For a quick refernce of the pins, shown below are the bottom view of the board and the corresponding pin mappings

Bottom view of CJMCU407

PIN MAPPING

USAGE: C ( row of pins close to the letter C of CJMCU) , U (close to U of cjmcu text)  and O (outer side) indicates the sides on the board. Note that the C side of the board has 18X2 (total 36) pins where as the U side has 24 pins and O side has 24 pins.

The row of pins close to the edje of the board is marked B and the inner row as A 

Example: PA0 on the stm32f4 is available at C6a which means close to C side , 6th pin in the inner row (ie away from the edge of the board)

I keep a printout of this for quick hookups without messing and turning the board and reading the small prints. on the bottom of the board

LED BLINKY
===========

To test the board, i hooked up the stlink, and used openocd to load the GPIO toggle firmware and connected a pair of led.