static uint16_t sht_readw(void)
{
uint8_t i;
uint16_t r = 0;
sda_input();
for(i = 0; i < 8; i++) {
scl_high();
r |= sda_get()?(1<<i):0;
scl_low();
}
sda_output();
sda_set(0);
scl_high();
scl_low();
sda_input();
for(i = 8; i < 16; i++) {
scl_high();
r |= sda_get()?(1<<i):0;
scl_low();
}
return r;
}
//------------------------------------------------------------------------
static unsigned int i2c_write_byte ( unsigned int b )
{
unsigned int ra;
for(ra=0x80;ra;ra>>=1)
{
i2c_delay();
if(ra&b) sda_high();
else sda_low();
i2c_delay();
scl_high();
i2c_delay();
scl_low();
i2c_delay();
sda_low();
i2c_delay();
}
i2c_delay();
sda_input();
i2c_delay();
scl_high();
i2c_delay();
ra=sda_read();
i2c_delay();
scl_low();
i2c_delay();
sda_output();
i2c_delay();
return(ra);
}
static void sht_sendb(uint8_t cmd)
{
uint8_t i;
sda_output();
for(i = 0; i < 8; i++) {
scl_low();
sda_set((cmd>>i)&1);
scl_high();
}
scl_low();
sda_input();
printf("foo!\n");
while(sda_get());
scl_high();
scl_low();
printf("bar!\n");
while(!sda_get());
printf("bla!\n");
i = 0;
while(sda_get()) {
i++;
if(i == 255) break;
usleep(10*1000);
}
}
static uint8_t getByte(const I2C_ABSTRACT_BUS* bus, boolean isLastByte){
const I2C_SOFTWARE_BUS* i2c = (const I2C_SOFTWARE_BUS*)bus;
int8_t i;
uint8_t b = 0;
sda_high(i2c);
for(i=7; i>=0; i--){
b <<= 1;
scl_high(i2c);
halfDelay();
if(pin_is_high(i2c->sda)){
b |= 1;
}
scl_low(i2c);
halfDelay();
}
// Put the ACK
if(isLastByte){
sda_high(i2c);
}else{
sda_low(i2c);
}
scl_high(i2c);
halfDelay(i2c);
scl_low(i2c);
sda_high(i2c);
return b; // return received byte
}
void sht_start(void)
{
sda_output();
sda_set(0);
scl_low();
scl_high();
sda_set(1);
scl_low();
}
// Send the start and address
// return TRUE if acknowledged
static boolean start(const I2C_ABSTRACT_BUS* bus, uint8_t addr, boolean writeMode){
boolean rtn = FALSE;
const I2C_SOFTWARE_BUS* i2c = (const I2C_SOFTWARE_BUS*)bus;
if(i2c){
sda_high(i2c);
halfDelay();
scl_high(i2c);
halfDelay();
sda_low(i2c);
halfDelay();
scl_low(i2c);
halfDelay();
// Send the device addr and direction
// uint8_t addr = device->addr & 0xfe;
if(writeMode==FALSE){
addr |= 1;
}else{
addr &= 0xfe;
}
rtn = putByte(bus, addr);
}
return rtn;
}
BOOL hw_i2c_master_rx(uint8_t *buf, uint8_t buf_len, BOOL ack)
{
BOOL error = FALSE;
BOOL send_ack;
#if USE_HARDWARE_I2C
uint8_t twsr;
cpu_disable_int();
while ((buf_len > 0) && !error) {
send_ack = (buf_len > 1) || ack;
if (send_ack) {
TWCR = TWICR_TWEN | TWICR_TWINT | TWICR_TWEA;
} else {
TWCR = TWICR_TWEN | TWICR_TWINT;
}
while ((TWCR & TWICR_TWINT) == 0);
*buf++ = TWDR;
twsr = TWSR & TW_STATUS_MASK;
if (send_ack) {
error = twsr != TW_MR_DATA_ACK;
} else {
error = twsr != TW_MR_DATA_NACK;
}
buf_len--;
}
#else
uint8_t data;
cpu_disable_int();
while ((buf_len > 0) && !error) {
uint8_t i;
send_ack = (buf_len > 1) || ack;
data = 0;
for (i = 0; i < 8; i++) {
data = (data << 1) | hw_i2c_read_bit();
}
*buf++ = data;
delay_T2();
if (send_ack) {
sda_low();
} else {
sda_hi();
}
delay_T2();
scl_hi();
delay_T2();
scl_low();
sda_hi();
buf_len--;
}
#endif
cpu_enable_int();
return !error;
}
// Return true if the slave acknowledges
static boolean getAck(const I2C_SOFTWARE_BUS* i2c){
sda_high(i2c); // allow slave to drive sda
scl_high(i2c);
halfDelay();
boolean rtn = pin_is_low(i2c->sda);
scl_low(i2c);
return rtn;
}
//------------------------------------------------------------------------
static void i2c_start ( void )
{
i2c_delay();
i2c_delay();
sda_low();
i2c_delay();
i2c_delay();
scl_low();
i2c_delay();
}
BOOL hw_i2c_master_start(uint8_t address, hw_i2c_rdwr_t hw_i2c_rd_wr)
{
#if USE_HARDWARE_I2C
BOOL error = FALSE;
uint8_t twsr;
cpu_disable_int();
TWCR = TWICR_TWEN | TWICR_TWINT | TWICR_TWSTA;
while ((TWCR & TWICR_TWINT) == 0);
twsr = TWSR & TW_STATUS_MASK;
if ((twsr != TW_START) && (twsr != TW_REP_START)) {
error = TRUE;
} else {
TWDR = (address & 0xfe) | hw_i2c_rd_wr;
TWCR = TWICR_TWEN | TWICR_TWINT;
while ((TWCR & TWICR_TWINT) == 0);
twsr = TWSR & TW_STATUS_MASK;
if (hw_i2c_rd_wr == hw_i2c_rd) {
error = twsr != TW_MR_SLA_ACK;
} else {
error = twsr != TW_MT_SLA_ACK;
}
}
cpu_enable_int();
return !error;
#else
cpu_disable_int();
delay_T2();
if (hold_bus) {
sda_hi();
delay_T2();
scl_hi();
delay_T2();
}
sda_low();
delay_T2();
scl_low();
hold_bus = TRUE;
hw_i2c_write_byte((address & 0xfe) | hw_i2c_rd_wr);
return hw_i2c_read_bit() == 0; // will call cpu_enable_int()
#endif
}
// Put a byte across the wire
// Return true if the slave acknowledges
static boolean putByte(const I2C_ABSTRACT_BUS* bus, uint8_t b){
const I2C_SOFTWARE_BUS* i2c = (const I2C_SOFTWARE_BUS*)bus;
int8_t i;
for(i=7; i>=0; i--){
if( b & 0x80 ){
sda_high(i2c);
}else{
sda_low(i2c);
}
scl_high(i2c);
b <<= 1;
scl_low(i2c);
}
return getAck(i2c); // return ACK value
}
void hw_i2c_write_byte(uint8_t data)
{
uint8_t i;
cpu_disable_int();
for (i = 0; i < 8; i++) {
delay_T2();
if (data & 0x80) {
sda_hi();
} else {
sda_low();
}
scl_hi();
delay_T2();
scl_low();
data <<= 1;
}
cpu_enable_int();
}
void hw_i2c_master_stop(void)
{
#if USE_HARDWARE_I2C
TWCR = TWICR_TWEN | TWICR_TWINT | TWICR_TWSTO;
#else
cpu_disable_int();
delay_T2();
scl_low();
sda_low();
delay_T2();
scl_hi();
delay_T2();
sda_hi();
hold_bus = FALSE;
cpu_enable_int();
_delay_ms(1); // FIXME, why is this needed when sending [0xA6 0 0][0xA7 r] to eeprom with logging off?
#endif
}
int main(void) {
int test;
unsigned char byte;
// PCF_ADRESS = 0; // Adresse des PCF'S
printf("*** i²c-LCD Test (c) Ingo Gerlach 10/2000 *** \n");
COM = 0; // Vorbelegung Ser - Port, 0 Automatisch suchen
set_port_delay(15); // Portdelay 0-255
test = init_iic(COM); // Init ii2c
printf("Suche i2c-Interface...");
if (test)
{
printf(" gefunden an Port 0x%03xh! \n",test);
} else {
printf("Interface nicht gefunden.\n");
exit (0);
}
/*
set_strobe(1); // Für den Seriellen Port nur dummy
io_disable(0);
*/
sda_high();
scl_high();
printf("read_sda %d \n",read_sda());
printf("read_scl %d \n",read_scl());
iic_start();
byte =getchar();
iic_stop();
sda_low();
scl_low();
printf("read_sda %d \n",read_sda());
printf("read_scl %d \n",read_scl());
lcd_backlight(0);
byte = getchar();
printf("deinit %d\n",deinit_iic());
return 0;
}
uint8_t hw_i2c_read_bit(void)
{
uint8_t bit;
cpu_disable_int();
delay_T2();
sda_hi();
scl_hi();
// wait for slave (clock stretching)
do {
delay_T2();
watchdog_reset(); // FIXME, add timeout
} while ((SCL_IN & _BV(SCL)) == 0);
bit = SDA_IN & _BV(SDA) ? 1 : 0;
delay_T2();
scl_low();
cpu_enable_int();
return bit;
}
// Send the start and address
// return TRUE if acknowledged
static boolean start(const I2C_DEVICE* device, boolean writeMode){
boolean rtn = FALSE;
const I2C_SOFTWARE_BUS* i2c = (const I2C_SOFTWARE_BUS*)(device->bus);
if(i2c){
sda_high(i2c);
halfDelay();
scl_high(i2c);
halfDelay();
sda_low(i2c);
halfDelay();
scl_low(i2c);
halfDelay();
// Send the device addr and direction
uint8_t addr = device->addr & 0xfe;
if(writeMode==FALSE){
addr |= 1;
}
rtn = putByte(device->bus, addr);
}
return rtn;
}
