stm32f407 DIS with external ADC(MCP3201)

[vinothraj]

Posted on August 24, 2012 at 17:25

Hi,

   i try to read the value from external adc by stm32f407.but i could not get the result from adc.MSP3201 is connected STM32f407 by SPI.MCP 3201does not have MOSI pin.the program runs good at 

SendChar('b')

; .the control is going to 

while (SPI_I2S_GetFlagStatus(SPI2, SPI_I2S_FLAG_RXNE) == RESET); repeatedly.

what i did mistakenly? did i correctly configure the  SPI2?i attached my programs.i need any suggestion from you.i have attached hiper terminal result also.please check it out #adc

[Tesla DeLorean]

Posted on August 24, 2012 at 17:53

RCC_APB2PeriphClockCmd(RCC_APB1Periph_SPI2, ENABLE);

APB1 surely?

[vinothraj]

Posted on August 28, 2012 at 08:45

sorry for late reply.Thank for Your valuable reply. i did mistake in that place.

RCC_APB2PeriphClockCmd(RCC_APB1Periph_SPI2, ENABLE);    //its Wrong oneRCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI2, ENABLE);   //its correct one.Again thank for You(clive1).

[vinothraj]

Posted on August 29, 2012 at 13:19

after doing the clock correction,i got same result as like previous Result.Any suggestion?

[frankmeyer9]

Posted on August 29, 2012 at 14:20

MCP 3201does not have MOSI pin  ...

It is obviously only a SPI slave device, so it does not have a MOSI pin (Master Out, Slave In). The Dout pin of the ADC thus needs to be connected to the controllers MISO pin. Check if your wiring is correct.

[vinothraj]

Posted on August 29, 2012 at 17:15

Thank for your response(fm).But its not my doubt.i knew that external adc has no Din.And i also connected the Dout of the external adc to MISO of stm32f4.MY problem is  that i did not get positive result from adc.the control is arrested in this place 

while (SPI_I2S_GetFlagStatus(SPI2, SPI_I2S_FLAG_RXNE) == RESET);

[frankmeyer9]

Posted on August 29, 2012 at 20:03

i knew that external adc has no Din.And i also connected the Dout of the external adc to MISO of stm32f4

O.k., this was not clear from your first post. That is a good point to bring a scope into play, to observe the signals at the pins. Can you see the clock ? Do you see outgoing data on Dout if you disconnect Dout from MISO ? The result would point to the source of your problems.

[vinothraj]

Posted on August 30, 2012 at 07:24

i do not have Scope,, to observe the signals at the pins.So i can not see.

[vinothraj]

Posted on August 30, 2012 at 13:01

yes. i got a value from external adc(mcp3201, mcp3208).

Thank for your support.(Clive1 and fm):)i learn from mistakes..