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#include "project.h"
#define SCL ((u8) 1 <<4)
#define SDA ((u8) 1 <<5)
#define BANK GPIOB
static u8
set (u8 sda, u8 scl)
{
u8 ret;
if (sda)
GPIO_WriteHigh (BANK, SDA);
else
GPIO_WriteLow (BANK, SDA);
if (scl)
GPIO_WriteHigh (BANK, SCL);
else
GPIO_WriteLow (BANK, SCL);
delay (4);
//delay_us (10);
ret = (GPIO_ReadInputData (BANK) & SDA) ? 1 : 0;
return ret;
}
u8
i2cb_send (u8 wot)
{
u8 i;
for (i = 0; i < 8; ++i) {
set (wot & 0x80, 0);
set (wot & 0x80, 1);
set (wot & 0x80, 0);
wot <<= 1;
}
set (1, 0);
i = set (1, 1);
set (1, 0);
return i;
}
u8
i2cb_send_addr (u8 addr, u8 rnw)
{
return i2cb_send (addr << 1 | rnw);
}
int
i2cb_send_data (u8 d)
{
return i2cb_send (d);
}
u8
i2cb_read (u8 ack)
{
u8 i, wot = 0;
for (i = 0; i < 8; ++i) {
wot <<= 1;
set (1, 0);
wot |= set (1, 1);
set (1, 0);
}
set (ack, 0);
set (ack, 1);
set (ack, 0);
return wot;
}
void
i2cb_start (void)
{
set (1, 1);
set (0, 1);
set (0, 0);
}
void
i2cb_stop (void)
{
set (0, 0);
set (0, 1);
set (1, 1);
}
int
i2cb_start_transaction (u8 a, u8 rnw)
{
i2cb_start();
return i2cb_send_addr (a, rnw);
}
void
i2cb_reset (void)
{
i2cb_start();
i2cb_stop();
i2cb_start();
i2cb_stop();
}
#if 0
void
i2cb_scan (void)
{
u8 r;
u16 i;
i2cb_reset();
for (i = 0; i < 128; ++i) {
i2cb_start();
i2cb_stop();
i2cb_start();
r = i2cb_send ((i << 1) | I2C_WRITE);
i2cb_stop();
if (!r)
printf ("target found at %02x\n", i);
}
i2cb_reset();
}
#endif
void
i2cb_init (void)
{
GPIO_Init (BANK, SDA, GPIO_MODE_OUT_OD_HIZ_SLOW);
GPIO_Init (BANK, SCL, GPIO_MODE_OUT_OD_HIZ_SLOW);
set (1, 1);
set (0, 1);
set (1, 0);
set (1, 1);
}
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