我和我哥哥一直试图让这个工作好几天，我们只是无法弄清楚我们做错了什么，我们真的可以使用一些帮助了！
我们要做的是使用BCM2835库，通过我们自己用C编写的程序从RPI扩展板上的光传感器读取数据。
这是我们使用的光传感器：TSL2561 https://cdn-shop.adafruit.com/datasheets/TSL2561.pdf
我们正在使用带有Raspbian的覆盆子pi B +模型（通过新手）。
这是我们使用的C库： http://www.airspayce.com/mikem/bcm2835/
我通过raspian配置激活了I2c。
我通过i2ctools检测到光传感器，并且正确地显示了地址0x29。
我们通过读取得到0值，并且我们使用振镜测试了我们的命令，似乎他确认了写命令。他只是没有发回任何东西......
有人可以帮助我们吗？
#include <bcm2835.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
uint16_t clk_div = BCM2835_I2C_CLOCK_DIVIDER_148;
uint8_t slave_address = 0x29; //0101001 - this is the sensor address
uint64_t delay = 70000;
int main(int argc, char **argv)
{
/*
DATA0LOW Ch 7:0 ADC channel 0 lower byte
DATA0HIGH Dh 7:0 ADC channel 0 upper byte
*/
char buffer[10]={0};
char addr;
uint16_t data;
uint8_t data2;
int i =0;
char writeBuff[1] = {0x8C}; ////Address the Ch0 lower data register
char readBuff[10];
char writeBuff2[2] = {0x8D}; ////Address the Ch0 upper data register
char readBuff2[10];
char *wb_ptr,*r_ptr,*wb_ptr2,*r_ptr2;
wb_ptr = writeBuff;
wb_ptr2 = writeBuff2;
r_ptr = readBuff;
r_ptr2 = readBuff2;
printf("Running ... \n");
bcm2835_init():
bcm2835_i2c_begin();
bcm2835_i2c_setSlaveAddress(slave_address); //0x29
printf("Clock divider set to: %d\n", clk_div);
printf("Slave address set to: %d or %X\n",slave_address,slave_address);
//needed according to datasheet to read although unsure if it needs to be sent in two writes or in one ? 0x83 instead of 0x80 + 0x03 ?
bcm2835_i2c_write(0x80, 1); //command register
bcm2835_i2c_write(0x03, 1); //command itself
bcm2835_delayMicroseconds(delay);
//--------------------------
while (1)
{
printf("reading data from light sensor\n");
bcm2835_i2c_write(wb_ptr, 1); // 0x8C
bcm2835_delayMicroseconds(delay);
data = bcm2835_i2c_read(readBuff,1);
bcm2835_delayMicroseconds(delay);
printf("Read Result 1 = %d\n", data);
bcm2835_i2c_write(wb_ptr2, 1); //0x8D
bcm2835_delayMicroseconds(delay);
data2 = bcm2835_i2c_read(readBuff2,1);
bcm2835_delayMicroseconds(delay);
printf("Read Result 2 = %d\n", data);
bcm2835_delay(1000);
}
bcm2835_i2c_end();
bcm2835_close();
printf("... done\n");
return 0;
}
这是一个快速编辑
#include <bcm2835.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
uint16_t clk_div = BCM2835_I2C_CLOCK_DIVIDER_148;
uint8_t slave_address = 0x29; //0101001 - this is the sensor address
uint64_t delay = 70000;
int main(int argc, char **argv)
{
/*
DATA0LOW Ch 7:0 ADC channel 0 lower byte
DATA0HIGH Dh 7:0 ADC channel 0 upper byte
*/
/*
enum bcm2835I2CReasonCodes { BCM2835_I2C_REASON_OK = 0x00, BCM2835_I2C_REASON_ERROR_NACK = 0x01, BCM2835_I2C_REASON_ERROR_CLKT = 0x02, BCM2835_I2C_REASON_ERROR_DATA = 0x04 }
*/
char buffer[10]={0};
char addr;
uint16_t data;
uint8_t data2;
uint8_t error = 0xff;
int i =0;
char writeBuff[1] = {0x8C}; ////Address the Ch0 lower data register
char readBuff[10];
char writeBuff2[2] = {0x8D}; ////Address the Ch0 upper data register
char readBuff2[10];
char writeBuff3[2] = {0x80};
char writeBuff4[2] = {0x03};
char *wb_ptr,*r_ptr,*wb_ptr2,*r_ptr2,*r_ptr3,*r_ptr4;
wb_ptr = writeBuff;
wb_ptr2 = writeBuff2;
r_ptr = readBuff;
r_ptr2 = readBuff2;
r_ptr3 = writeBuff3;
r_ptr4 = writeBuff4;
printf("Running ... \n");
bcm2835_init();
bcm2835_i2c_begin();
bcm2835_i2c_setSlaveAddress(slave_address); //0x29
printf("Clock divider set to: %d\n", clk_div);
printf("Slave address set to: %d or %X\n",slave_address,slave_address);
//needed according to datasheet to read although unsure if it needs to be sent in two writes or in one ? 0x83 instead of 0x80 + 0x03 ?
bcm2835_i2c_write(r_ptr3, sizeof(r_ptr3)); //command register
bcm2835_i2c_write(r_ptr4, sizeof(r_ptr4)); //command itself
bcm2835_delayMicroseconds(delay);
//--------------------------
// Blink
while (1)
{
printf("reading data from light sensor\n");
error = bcm2835_i2c_write(wb_ptr, sizeof(wb_ptr)); // 0x8C
bcm2835_delayMicroseconds(delay);
data = bcm2835_i2c_read(readBuff,sizeof(readBuff));
bcm2835_delayMicroseconds(delay);
printf("readbuff1 = 0x%02X \n",readBuff);
printf("error result = 0x%02X\n", error);
printf("Read Result 1 = 0x%02X\n", data);
error = bcm2835_i2c_write(wb_ptr2, sizeof(wb_ptr2)); //0x8D
bcm2835_delayMicroseconds(delay);
data2 = bcm2835_i2c_read(readBuff2,sizeof(readBuff2));
bcm2835_delayMicroseconds(delay);
printf("readbuff2 = 0x%02X \n",readBuff2);
printf("error result = 0x%02X\n", error);
printf("Read Result 2 = 0x%02X\n", data2);
bcm2835_delay(1000);
}
bcm2835_i2c_end();
bcm2835_close();
printf("... done\n");
return 0;
}
答案 0 :(得分：1)
我设法解决了这个问题，我遇到了几个问题，其中一个问题就是我正在通过错误的地址发送命令，它必须是0xa0而不是0x80。
#include <bcm2835.h>
#include <stdio.h>
int main(void)
{
/*
DATA0LOW Ch 7:0 ADC channel 0 lower byte
DATA0HIGH Dh 7:0 ADC channel 0 upper byte
*/
/*
enum bcm2835I2CReasonCodes { BCM2835_I2C_REASON_OK = 0x00, BCM2835_I2C_REASON_ERROR_NACK = 0x01, BCM2835_I2C_REASON_ERROR_CLKT = 0x02, BCM2835_I2C_REASON_ERROR_DATA = 0x04 }
*/
if (!bcm2835_init())
return 1;
char uitgelezenTempWaarde[1];
int totalTemp[2];
int error =0;
bcm2835_i2c_begin(); // start i2c
bcm2835_i2c_setSlaveAddress(0x29); // slave address
bcm2835_i2c_set_baudrate(1000); // default
//----------- turn channels on for measurement ------
uitgelezenTempWaarde[0] = 0xa0;
error = bcm2835_i2c_write(uitgelezenTempWaarde,1);
if(error != 0x00)
{
printf("i2c error! : 0x%02X \n",error);
}
uitgelezenTempWaarde[0] = 0x03;
error = bcm2835_i2c_write(uitgelezenTempWaarde,1);
if(error != 0x00)
{
printf("i2c error! : 0x%02X \n",error);
}
bcm2835_delay(500);
error = bcm2835_i2c_read(uitgelezenTempWaarde,1);
if(error != 0x00)
{
printf("i2c error! : 0x%02X \n",error);
}
//----------- read data ------
uitgelezenTempWaarde[0] = 0xac; //DATA0LOW Ch 7:0 ADC channel 0 lower byte
error = bcm2835_i2c_write(uitgelezenTempWaarde,1);
if(error != 0x00)
{
printf("i2c error! : 0x%02X \n",error);
}
error = bcm2835_i2c_read(uitgelezenTempWaarde,1);
if(error != 0x00)
{
printf("i2c error! : 0x%02X \n",error);
}
totalTemp[1]= (int)uitgelezenTempWaarde[0];
uitgelezenTempWaarde[0] = 0xad; //DATA0HIGH Dh 7:0 ADC channel 0 upper byte
error = bcm2835_i2c_write(uitgelezenTempWaarde,1);
if(error != 0x00)
{
printf("i2c error! : 0x%02X \n",error);
}
error = bcm2835_i2c_read(uitgelezenTempWaarde,1);
if(error != 0x00)
{
printf("i2c error! : 0x%02X \n",error);
}
totalTemp[0] = (int)uitgelezenTempWaarde[0]; //
totalTemp[0] *= 256; //hex conversion for the highest byte so it is seen as a high number (16 bits)
printf("The light value is :%d\n",totalTemp[0]+totalTemp[1]);
bcm2835_i2c_end();
bcm2835_close();
return 0;
}