159 lines
4.5 KiB
C
159 lines
4.5 KiB
C
#include "mlx90614.h"
|
|
#include "smbus.h"
|
|
#include "hi_time.h"
|
|
|
|
|
|
/***************************************************************************
|
|
* @brief SMBus start bit
|
|
* @param None
|
|
* @retval None
|
|
****************************************************************************/
|
|
void SMBus_Start(void)
|
|
{
|
|
SMBUS_SDA_H();
|
|
hi_udelay(5);
|
|
SMBUS_SCL_H();
|
|
hi_udelay(5);
|
|
SMBUS_SDA_L();
|
|
hi_udelay(5);
|
|
SMBUS_SCL_L();
|
|
hi_udelay(5);
|
|
}
|
|
|
|
/***************************************************************************
|
|
* @brief SMBus stop bit
|
|
* @param None
|
|
* @retval None
|
|
****************************************************************************/
|
|
void SMBus_Stop(void)
|
|
{
|
|
SMBUS_SCL_L();
|
|
hi_udelay(5);
|
|
SMBUS_SDA_L();
|
|
hi_udelay(5);
|
|
SMBUS_SCL_H();
|
|
hi_udelay(5);
|
|
SMBUS_SDA_H();
|
|
}
|
|
/*******************************************************************************
|
|
* 函数名: SMBus_SendBit
|
|
* 功能: Send a bit on SMBus 82.5kHz
|
|
* Input : bit_out
|
|
* Output : None
|
|
* Return : None
|
|
*******************************************************************************/
|
|
void SMBus_SendBit(uint8_t bit_out)
|
|
{
|
|
if(bit_out==0)
|
|
{
|
|
SMBUS_SDA_L();
|
|
}
|
|
else
|
|
{
|
|
SMBUS_SDA_H();
|
|
}
|
|
hi_udelay(2); // Tsu:dat = 250ns minimum
|
|
SMBUS_SCL_H(); // Set SCL line
|
|
hi_udelay(6); // High Level of Clock Pulse
|
|
SMBUS_SCL_L(); // Clear SCL line
|
|
hi_udelay(3); // Low Level of Clock Pulse
|
|
return;
|
|
}
|
|
static uint8_t SMBUS_SDA_READ(void)
|
|
{
|
|
IotGpioValue temp = {0};
|
|
IoTGpioGetInputVal(WIFI_IOT_IO_NAME_GPIO_12,&temp);
|
|
return temp;
|
|
}
|
|
|
|
/*******************************************************************************
|
|
* Function Name : SMBus_ReceiveBit
|
|
* Description : Receive a bit on SMBus
|
|
* Input : None
|
|
* Output : None
|
|
* Return : Ack_bit
|
|
*******************************************************************************/
|
|
uint8_t SMBus_ReceiveBit(void)
|
|
{
|
|
uint8_t Ack_bit;
|
|
|
|
SMBUS_SDA_H(); //引脚靠外部电阻上拉，当作输入
|
|
hi_udelay(2); // High Level of Clock Pulse
|
|
SMBUS_SCL_H(); // Set SCL line
|
|
hi_udelay(5); // High Level of Clock Pulse
|
|
if (SMBUS_SDA_READ())
|
|
{
|
|
Ack_bit=1;
|
|
}
|
|
else
|
|
{
|
|
Ack_bit=0;
|
|
}
|
|
SMBUS_SCL_L(); // Clear SCL line
|
|
hi_udelay(3); // Low Level of Clock Pulse
|
|
|
|
return Ack_bit;
|
|
}
|
|
|
|
/*******************************************************************************
|
|
* 函数名: SMBus_SendByte
|
|
* 功能: Send a byte on SMBus
|
|
* Input : Tx_buffer
|
|
* Output : None
|
|
* Return : None
|
|
*******************************************************************************/
|
|
uint8_t SMBus_SendByte(uint8_t Tx_buffer)
|
|
{
|
|
uint8_t Bit_counter;
|
|
uint8_t Ack_bit;
|
|
uint8_t bit_out;
|
|
|
|
for(Bit_counter=8; Bit_counter; Bit_counter--)
|
|
{
|
|
if (Tx_buffer&0x80)
|
|
{
|
|
bit_out=1; // If the current bit of Tx_buffer is 1 set bit_out
|
|
}
|
|
else
|
|
{
|
|
bit_out=0; // else clear bit_out
|
|
}
|
|
SMBus_SendBit(bit_out); // Send the current bit on SDA
|
|
Tx_buffer<<=1; // Get next bit for checking
|
|
}
|
|
|
|
Ack_bit=SMBus_ReceiveBit(); // Get acknowledgment bit
|
|
return Ack_bit;
|
|
}
|
|
|
|
/*******************************************************************************
|
|
* 函数名: SMBus_ReceiveByte
|
|
* 功能: Receive a byte on SMBus
|
|
* Input : ack_nack
|
|
* Output : None
|
|
* Return : RX_buffer
|
|
*******************************************************************************/
|
|
uint8_t SMBus_ReceiveByte(uint8_t ack_nack)
|
|
{
|
|
uint8_t RX_buffer;
|
|
uint8_t Bit_Counter;
|
|
|
|
for(Bit_Counter=8; Bit_Counter; Bit_Counter--)
|
|
{
|
|
if(SMBus_ReceiveBit()) // Get a bit from the SDA line
|
|
{
|
|
RX_buffer <<= 1; // If the bit is HIGH save 1 in RX_buffer
|
|
RX_buffer |=0x01;
|
|
}
|
|
else
|
|
{
|
|
RX_buffer <<= 1; // If the bit is LOW save 0 in RX_buffer
|
|
RX_buffer &=0xfe;
|
|
}
|
|
}
|
|
SMBus_SendBit(ack_nack); // Sends acknowledgment bit
|
|
return RX_buffer;
|
|
}
|
|
|
|
|