arti/dht_test
1
0
Fork 0
Code Releases Activity

Works!

Browse Source
This commit is contained in:
Arti Zirk 2021-07-08 01:02:05 +03:00
parent d23915d79a
commit 1c587d5ba3
1 changed files with 56 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

67
main.c
View File

@ -34,14 +34,15 @@ enum DHT11_STATE {
DHT11_BEGIN_START, // We drive DATA Low for min 18ms
DHT11_END_START, // We drive DATA High and set it to input
DHT11_RESPONSE, // Wait for DHT to drive DATA Low
DHT11_DATA,
DHT11_END
DHT11_DATA, // Receiving data
DHT11_END, // Got last bit
DHT11_TIMEOUT, // Not response or data got
};
int g_dht11_state = DHT11_STOP;
int g_dht_i = 0;
uint16_t g_dht_vals[100] = {0};
uint16_t g_dht_vals[43] = {0};
static void delay(int count)
{
@ -106,7 +107,7 @@ void tim3_isr(void)
} else {
puts("overflow");
}
g_dht11_state = DHT11_STOP;
g_dht11_state = DHT11_TIMEOUT;
timer_disable_counter(TIM3);
//timer_set_counter(TIM3, 0);
@ -127,7 +128,6 @@ void tim3_isr(void)
// setup timer to wait for start response from dht11
timer_ic_set_polarity(TIM3, TIM_IC3, TIM_IC_FALLING);
//timer_ic_set_polarity(TIM3, TIM_IC3, TIM_IC_RISING);// TIM_IC_RISING
timer_clear_flag(TIM3, TIM_SR_CC3IF);
timer_ic_enable(TIM3, TIM_IC3);
//puts("waiting for response");
@ -144,17 +144,23 @@ void tim3_isr(void)
//gpio_toggle(GPIOB, GPIO2);
//timer_ic_disable(TIM3, TIM_IC3);
//timer_clear_flag(TIM3, TIM_SR_CC3IF);
//timer_ic_set_polarity(TIM3, TIM_IC3, TIM_IC_FALLING);// TIM_IC_RISING
//timer_ic_set_polarity(TIM3, TIM_IC3, TIM_IC_RISING);
g_dht_vals[g_dht_i++] = TIM_CCR3(TIM3); // store captured high time value
//timer_ic_enable(TIM3, TIM_IC3);
//gpio_toggle(GPIOB, GPIO2);
} else {
//gpio_toggle(GPIOB, GPIO2);
g_dht11_state = DHT11_DATA;
g_dht_vals[g_dht_i] = TIM_CCR3(TIM3) - g_dht_vals[g_dht_i-1]; // store length from last sample
g_dht_i++;
g_dht_vals[g_dht_i++] = TIM_CCR3(TIM3); // store length from last sample
//gpio_toggle(GPIOB, GPIO2);
}
if (g_dht_i > 41) {
// we have the whole packet
g_dht11_state = DHT11_END;
timer_disable_counter(TIM3);
}
timer_clear_flag(TIM3, TIM_SR_CC3IF);
gpio_toggle(GPIOB, GPIO2);
@ -192,6 +198,35 @@ static void dht_start(void)
}
static void dht_parse_data(){
int8_t data[5] = {0};
uint8_t checksum = 0;
int data_index = 0;
int data_bit = 7;
for (int i=2; i < 42; i++){ // First 2 pulses are start of response, ignore them
uint16_t bit_time = g_dht_vals[i] - g_dht_vals[i-1];
if (bit_time > 100) {
data[data_index] |= 1 << data_bit;
}
data_bit--;
if (data_bit < 0) {
data_bit = 7;
data_index++;
}
}
for (int i = 0; i < 4; i++){
checksum += data[i];
}
if (checksum == data[4]) {
SEGGER_RTT_printf(0, "Humidity: %d.%d%%; Temperature: %d.%dC\n",
data[0], data[1], data[2], data[3]);
} else {
SEGGER_RTT_printf(0, "Checksum did not match, %x != %x\n", checksum, data[4]);
}
}
static void dht_start_signal(void)
{
gpio_set_mode(DHT_PORT, GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, DHT_PIN);
@ -206,6 +241,7 @@ static void dht_start_signal(void)
int main(void)
{
int i = 0;
bool wait = false;
puts("Start");
rcc_clock_setup_pll(&rcc_hse_configs[RCC_CLOCK_HSE8_72MHZ]);
gpio_setup();
@ -215,11 +251,20 @@ int main(void)
while (1) {
/* Using API function gpio_toggle(): */
gpio_toggle(GPIOB, GPIO1); /* LED on/off */
delay(10000000);
dht_start();
i++;
SEGGER_RTT_printf(0, "Poll: %d\n", i);
delay(10000000);
dht_start();
wait = true;
while (wait) {
switch (g_dht11_state) {
case DHT11_END:
dht_parse_data();
// fall through
case DHT11_TIMEOUT:
wait = false;
}
}
}
return 0;