static int dht11_read(uint8_t pin, uint8_t *buf, uint8_t buflen)
{
if (buflen < DHT_DATA_LEN)
return DHT_ENOSPACE;
/* Send START signal by pulling low the Data Signal bus at least 18ms */
gpio_setup(pin, OUTPUT);
gpio_write(pin, LOW);
mcu_delay(20000);
/* Release the Data Signal bus and wait 20~40us for DHT's response */
gpio_write(pin, HIGH);
gpio_setup(pin, INPUT);
mcu_delay(30);
/* DHT responds by pulling the Data Signal bus for 80us */
while (gpio_read(pin) != LOW);
while (gpio_read(pin) == LOW);
/* DHT pulls high the Data Signal bus for 80us and prepares the sending data */
while (gpio_read(pin) != LOW);
uint8_t index, checksum = 0;
for (index = 0; index < DHT_DATA_LEN; index++) {
uint8_t bit, value = 0;
for (bit = 0x80; bit; bit >>= 1) {
/* DHT pulls low the Data Signal bus for 50us to start sending each bit */
while (gpio_read(pin) == LOW);
/* DHT pulls high the Data Signal bus, the length of duration is
determined by value of the sending bit. 0: 26~28us, 1: 70us */
mcu_delay(40);
if (gpio_read(pin) != LOW) {
while (gpio_read(pin) != LOW);
value |= bit;
}
}
buf[index] = value;
}
/* Acquire the Data Signal bus and keep it high */
gpio_setup(pin, OUTPUT);
gpio_write(pin, HIGH);
for (index = 0; index < DHT_DATA_LEN-1; index++)
checksum += buf[index];
return (buf[4] == checksum)? DHT_SUCCESS : DHT_ECHECKSUM;
}
/* Send CMD55/ACMD41 until the card returns 0 or times out */
static int wakeup(struct sdcard_spi_dev_t *dev, uint8_t is_sdhc)
{
uint8_t response;
uint16_t attempt_count = INIT_ATTEMPT_COUNT_MAX;
do {
attempt_count--;
if (send_cmd(dev, &response, CMD55_APP_CMD, 0, 0x65) < 0)
return -1;
if (is_sdhc) {
if (send_cmd(dev, &response, ACMD41_SEND_OP_COND, 0x40000000, 0x77) < 0)
return -1;
}
else {
if (send_cmd(dev, &response, ACMD41_SEND_OP_COND, 0, 0xE5) < 0)
return -1;
}
if (response == 0)
break;
/* Let's try again 10 ticks later if the card is not ready */
mcu_delay(TICKS_PER_SEC / 100);
} while (attempt_count > 0 && response != 0);
if (attempt_count == 0 && response != 0)
return -1;
return 0;
}
void send_high_bit() {
//debug_print(DBG_INFO, "1 \n");
pwm_configure(pwm1, MESSAGE_DUTY_HIGH, MESSAGE_PERIOD); // 1
pwm_configure(pwm2, MESSAGE_DUTY_HIGH, MESSAGE_PERIOD);
pwm_configure(pwm3, MESSAGE_DUTY_HIGH, MESSAGE_PERIOD);
pwm_configure(pwm4, MESSAGE_DUTY_HIGH, MESSAGE_PERIOD);
pwm_enable(pwm1);
pwm_enable(pwm2);
pwm_enable(pwm3);
pwm_enable(pwm4);
mcu_delay(MESSAGE_SLEEP);
}
void send_low_bit() {
//debug_print(DBG_INFO, "0 \n");
pwm_configure(pwm1, MESSAGE_DUTY_LOW, MESSAGE_PERIOD); // 0
pwm_configure(pwm2, MESSAGE_DUTY_LOW, MESSAGE_PERIOD);
pwm_configure(pwm3, MESSAGE_DUTY_LOW, MESSAGE_PERIOD);
pwm_configure(pwm4, MESSAGE_DUTY_LOW, MESSAGE_PERIOD);
pwm_enable(pwm1);
pwm_enable(pwm2);
pwm_enable(pwm3);
pwm_enable(pwm4);
mcu_delay(MESSAGE_SLEEP);
}
void send_preamble_sequence(int preamble_duration) {
//debug_print(DBG_INFO, "Preamble\n");
pwm_configure(pwm1, PREAMBLE_DUTY, PREAMBLE_PERIOD);
pwm_configure(pwm2, PREAMBLE_DUTY, PREAMBLE_PERIOD);
pwm_configure(pwm3, PREAMBLE_DUTY, PREAMBLE_PERIOD);
pwm_configure(pwm4, PREAMBLE_DUTY, PREAMBLE_PERIOD);
pwm_enable(pwm1);
pwm_enable(pwm2);
pwm_enable(pwm3);
pwm_enable(pwm4);
mcu_delay(preamble_duration*PREAMBLE_SLEEP);
}
/* Send CMD1 until the card returns 0 or times out */
static int old_wakeup(struct sdcard_spi_dev_t *dev)
{
uint8_t response;
uint16_t attempt_count = INIT_ATTEMPT_COUNT_MAX;
do {
attempt_count--;
if (send_cmd(dev, &response, CMD1_SEND_OP_COND, 0, 0xF9) < 0)
return -1;
if (response == 0)
break;
/* Let's try again 10 ticks later if the card is not ready */
mcu_delay(TICKS_PER_SEC / 100);
} while (attempt_count > 0 && response != 0);
if (attempt_count == 0 && response != 0)
return -1;
return 0;
}
void mcu_main()
{
// by default, the edison has ID 0
int edisonID = 0;
// if we pass in an argument, use it for the edisonID
// please pass in an integer
//if (argc == 2) {
//edisonID = atoi(argv[1]);
//}
int temp;
while (1)
{
//int host_receive(unsigned char *buf, int length)
temp = host_receive((unsigned char *)host_message, BUFFER_LENGTH);
if (temp > 0)
{
debug_print(DBG_INFO, "Received a Message!\n");
host_send((unsigned char*)"hello mcu\n", 10);
preamble_length = host_message[0];
}
// Preamble - Signals the Receiver Message Incoming
send_preamble_sequence(preamble_length);
// Sending Edison Board ID # - 2 bits, MSB then LSB
switch (edisonID) {
case 0:
send_low_bit(); // Send lsb bit 0 = LOW
send_low_bit(); // Send msb bit 1 = LOW
break;
case 1:
send_high_bit(); // Send lsb bit 0 = HIGH
send_low_bit(); // Send msb bit 1 = LOW
break;
case 2:
send_low_bit(); // Send lsb bit 0 = LOW
send_high_bit(); // Send msb bit 1 =
break;
case 3:
send_high_bit(); // Send lsb bit 0 = HIGH
send_high_bit(); // Send msb bit 1 = HIGH
break;
default:
send_low_bit(); // Send lsb bit 0 = LOW
send_low_bit(); // Send msb bit 1 = LOW
}
// Sending Edison IR Emitter ID # - 2 bits, MSB then LSB
// pwm1 = 00 = short-long/short-long = 5-20/5-20
// pwm2 = 01 = short-long/long-short = 5-20/20-5
// pwm3 = 10 = long-short/short-long = 20-5/5-20
// pwm4 = 11 = long-short/long-short = 20-5/20-5
// First Bit
pwm_configure(pwm1, MESSAGE_DUTY_LOW, MESSAGE_PERIOD); // 0
pwm_configure(pwm2, MESSAGE_DUTY_LOW, MESSAGE_PERIOD); // 0
pwm_configure(pwm3, MESSAGE_DUTY_HIGH, MESSAGE_PERIOD); // 1
pwm_configure(pwm4, MESSAGE_DUTY_HIGH, MESSAGE_PERIOD); // 1
pwm_enable(pwm1);
pwm_enable(pwm2);
pwm_enable(pwm3);
pwm_enable(pwm4);
mcu_delay(MESSAGE_SLEEP);
// Second Bit
pwm_configure(pwm1, MESSAGE_DUTY_LOW, MESSAGE_PERIOD); // 0
pwm_configure(pwm2, MESSAGE_DUTY_HIGH, MESSAGE_PERIOD); // 1
pwm_configure(pwm3, MESSAGE_DUTY_LOW, MESSAGE_PERIOD); // 0
pwm_configure(pwm4, MESSAGE_DUTY_HIGH, MESSAGE_PERIOD); // 1
pwm_enable(pwm1);
pwm_enable(pwm2);
pwm_enable(pwm3);
pwm_enable(pwm4);
mcu_delay(MESSAGE_SLEEP);
}
}
