STM32F429 Discovery kit pinout

[alimed]

Posted on April 29, 2014 at 15:01

Hello, I have to develop a board to attach to an STM32F429 Discovery kit to control a comercial display. In the design i found that the pins of the discovery kit give only a certain funcionality. Is not other way of remap this connections? For example: if i need i2c communication is no way to make it with the actual configuration for this board.

[Tesla DeLorean]

Posted on April 29, 2014 at 15:36

The STM32F429I-DISCO is VERY limited in it's ability to escape pin/peripheral functions.

The Data Manual for the PART covers exactly what pins and what peripherals escape the chip itself, and combined with the User Manual for the BOARD, should be sufficient to make a functional determination.

People have historically used pen and paper, excel sheets, and Micro Xplorer to review the available escape options.

I personally would just go with a 176-pin, or higher, design for the STM32F429 because most others will be a compromise.

[alimed]

Posted on April 29, 2014 at 16:08

I read the manuals, and is very restricted the pins and peripheral that escape the board. In the discovery kit manual is related a pin of the connector with a function (peripheral). It is impossible to change the alternate function of a pin that escape the board (with the alternate function of the MCU pins)?

[waclawek.jan]

Posted on April 29, 2014 at 16:37

Impossible is such a strong word... Impractical, perhaps...

You can still use buses like I2C, as long as there is no address conflict, or the external memory bus, if you can find a free chip select. You can use those IO which are not driven by the onboard circuitry, as long as it won't cause havoc in the connected chips. At the end of the day, you can desolder chips you don't need.

JW

[Tesla DeLorean]

Posted on April 29, 2014 at 16:48

As I have repeatedly stated here on the forum, the STM32F429I-DISCO is designed to demonstrate LCD + SDRAM functionality, that is ALL. The design will not see effective break-out boards because the aforementioned interfaces suck up so many pins in ways that preclude the escape of other functionality (ETH, ADC, DCMI, SDIO, etc).

This is a convergence of poor design and poor part choice. The only way to fix it is to use a higher pin count part.

[alimed]

Posted on April 29, 2014 at 16:57

Yes, I´ll take your advice and move to a higher pin STM4F29 in order to develop an optimal design. Thanks

[gbarbour]

Posted on April 30, 2014 at 16:56

Hello,

I am struggling with the same problem. I already have the STM32F429I-Disco board and instead of throwing it away I want to use it for a test device. I need 30+ digital I/Os and there are only 23 free pins on the board.

According to the spreadsheet at:

http://translate.googleusercontent.com/translate_c?depth=2&hl=de&ie=UTF8&prev=_t&rurl=translate.google.com&sl=de&tl=en&u=http://mikrocontroller.bplaced.net/wordpress/%3Fpage_id%3D2848&usg=ALkJrhjUTcruzLgR5jTH6MmVDPaAv03GQg

SPI1 (PA5-SCK, PA7-MOSI, PB8-MISO)

or SPI4 (PE2-SCK, PE5-MISO, PE6-MOSI) can be used.

Using either of those SPI ports, I expect that something like the MCP23S17 or MCP23S18 can be used as an SPI I/O expander.

Using other available Disco pins to enable a given I/O expander chip should, theoretically, allow quite a few I/Os to be controlled in spite of the limited free pins on the board.

You might try something like that.

I also wonder if one can tie into I2C#3 (PC9-SDA, PA8-SCL) which appears to just go to the Touch Screen.

I would like to use the 176 pin version of the chip but I don't know enough to design a board for it which would include the SDRAM, debug interface, and LCD connections. And I don't know where to find a pre-made one.

G'luck.

[Tokarev.Konstantin]

Posted on March 26, 2015 at 20:00

Hello!

Just an idea, but you could also remove the integrated display by removing the white plastic module from the metal frame, carefully lifting it and unsoldering the flexible cable from the board itself, which would give you a fair amount of free pins for your use.

Another idea is to unsolder the accelerometer, thus freeing the pins used by it.

Best regards,

Konstantin

[Tesla DeLorean]

Posted on March 27, 2015 at 11:51

Just an idea, but you could...

About a year late to the party though.

The

http://www.wvshare.com/product/Core429I.htm

board from WaveShare would allow for much better functional breakout.

http://www.waveshare.com/product/mcu-tools/stm32/open/open429i-c-standard.htm