Hi,
I have small problem with connecting external sensor to my F103RB NUCLEO board. Im trying to connect Adafruit CAP1188 module through SPI normal mode. I send example messages and dont seem to get the right answer(I get 0). I just want to check if everything works correctly and then I want to start writing the proper program. I think there might be a problem with my spi config. Im begginer at programming STM32. Can anyone check my code and help me fix potential problems? Im steering CS pin through PIN_0 on my NUCLEO.
According documentation reading byte 51h should return C8h
#include "stm32f10x.h"
#include <stdio.h>
uint8_t spi_sendrecv(uint8_t byte)
{
// wait for input buffer
while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_TXE) == RESET);
SPI_I2S_SendData(SPI1, byte);
// wait for output buffer
while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_RXNE) == RESET);
return SPI_I2S_ReceiveData(SPI1);
}
uint8_t read_reg()
{
GPIO_ResetBits(GPIOC, GPIO_Pin_0);
spi_sendrecv(0x7A); //Reset
spi_sendrecv(0x7A); //Reset
spi_sendrecv(0x7D); // SET ADDRESS POINTER
spi_sendrecv(0x51); //ADDRES
spi_sendrecv(0x7F); // READ
uint8_t value = spi_sendrecv(0xff); //send random message to recieve answer
GPIO_SetBits(GPIOC, GPIO_Pin_0);
return value;
}
int main(void)
{
RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1,ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC, ENABLE);
//SCK MOSI
GPIO_InitTypeDef gpio;
GPIO_StructInit(&gpio);
gpio.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_7; //SCK, MOSI
gpio.GPIO_Mode = GPIO_Mode_AF_PP; //output push pull
gpio.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &gpio);
/ MISO
gpio.GPIO_Pin = GPIO_Pin_6;
gpio.GPIO_Mode = GPIO_Mode_IN_FLOATING; //input
GPIO_Init(GPIOA, &gpio);
gpio.GPIO_Pin = GPIO_Pin_0; // CS -> PIN_0
gpio.GPIO_Mode = GPIO_Mode_Out_PP;
GPIO_Init(GPIOC, &gpio);
GPIO_SetBits(GPIOC, GPIO_Pin_0);
SPI_InitTypeDef spi;
SPI_StructInit(&spi);
spi.SPI_Mode = SPI_Mode_Master;
spi.SPI_NSS = SPI_NSS_Soft; // NSS = CS
spi.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_16;
SPI_Init(SPI1, &spi);
SPI_Cmd(SPI1, ENABLE);
while(1){
uint8_t result1 = read_reg(); //Checking debug, I see 0x00
}
}
