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author | Karel Kočí <cynerd@email.cz> | 2016-03-08 16:10:33 +0100 |
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committer | Karel Kočí <cynerd@email.cz> | 2016-03-08 16:10:33 +0100 |
commit | 5d29fe79d30f430ae326d9dc57ccfaed6fe61328 (patch) | |
tree | 8341804d561c0060176cbebc3f9a57c7c07f7816 /src/sensors | |
parent | 4e773191d447ac434536262a6f204dd991d4ad77 (diff) | |
download | avr-ioe-5d29fe79d30f430ae326d9dc57ccfaed6fe61328.tar.gz avr-ioe-5d29fe79d30f430ae326d9dc57ccfaed6fe61328.tar.bz2 avr-ioe-5d29fe79d30f430ae326d9dc57ccfaed6fe61328.zip |
Another full update of current work
Diffstat (limited to 'src/sensors')
-rw-r--r-- | src/sensors/dht22.c | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/src/sensors/dht22.c b/src/sensors/dht22.c new file mode 100644 index 0000000..9653ba5 --- /dev/null +++ b/src/sensors/dht22.c @@ -0,0 +1,117 @@ +#include <sensors/dht22.h> + +#ifdef CONFIG_IOE_SENSOR_DHT22 + +#define PP dht22_ports[pi] +#define PPP dht22_ports[dht22_measurement.pi] + +#define TIMEOUT F_CPU/40000 + +#define STATUS_NONE 0 +#define STATUS_COMPLETE 1 +#define STATUS_TIMEOUT 2 + +#define PORT_SENSORW 4 +#define PORT_SENSORRESP_L 3 +#define PORT_SENSORRESP_H 2 +#define PORT_H 1 +#define PORT_L 0 + +struct { + uint8_t index; + uint8_t data[5]; + volatile uint8_t status; + uint8_t pi; + uint8_t port_status; +} dht22_measurement; + +inline void dht22_init(uint8_t pi) { + // Set port as output and set level hight + *(PP.DDR) |= PP.MASK; + *(PP.PORT) |= PP.MASK; + // Enable all pin change interrupts + PCIFR = 0xff; +} + + +inline void dht22_read_deac(uint8_t status) { + dht22_measurement.status = status; + // Disable pin change interrupt + *(PPP.PCMSK) &= ~PPP.PCMSK_MASK; + timer_disable(CONFIG_IOE_SENSOR_DHT22_TIMER); +} + +// This is called from pcint.c +void dht22_read_pcint(void) { + switch (dht22_measurement.port_status) { + case PORT_L: + if (!(*(PPP.PIN) & PPP.MASK)) + return; + dht22_measurement.port_status = PORT_H; + break; + case PORT_H: + if (*(PPP.PIN) & PPP.MASK) + return; + dht22_measurement.port_status = PORT_L; + register uint16_t val; + val = timer_value(CONFIG_IOE_SENSOR_DHT22_TIMER); + // TODO compare value + if (val < 1) { + dht22_measurement.data[dht22_measurement.index / 8] + } + if (++(dht22_measurement.index) == 40) { + dht22_read_deac(STATUS_COMPLETE); + return; + } + break; + default: + if (((*(PPP.PIN) & PPP.MASK) && dht22_measurement.port_status == 3) + || !(*(PPP.PIN & PPP.MASK))) + return; + dht22_measurement.port_status--; + } + timer_reset(CONFIG_IOE_SENSOR_DHT22_TIMER); +} + +void dht22_read_timer_overflow(void) { + dht22_read_deac(STATUS_TIMEOUT); +} + +int8_t dht22_read(uint8_t pi, struct dht22_value *rh, + struct dht22_value *t) { + dht22_measurement.index = 0; + dht22_measurement.status = STATUS_NONE; + dht22_measurement.pi = pi; + dht22_measurement.port_status = PORT_SENSORW; + + // Pull port down for 500us + *(PP.PORT) &= ~PP.MASK; + _delay_us(500); + // Initialize timer + timer_init(CONFIG_IOE_SENSOR_DHT22_TIMER, TIMER_DIVIDER_64); + timer_sethook(CONFIG_IOE_SENSOR_DHT22_TIMER, + dht22_read_timer_overflow); + // Set pin change interrupt + *(PP.PCMSK) |= PP.PCMSK_MASK; + // Set port as output and pull-up resistor + *(PP.DDR) &= ~PP.MASK; + *(PP.PORT) |= PP.MASK; + // Delay till reading is done + taskDelayTill(&(dht22_measurement.status)); + + // Copy data + rh->integral = dht22_measurement.data[0]; + rh->decimal = dht22_measurement.data[1]; + t->integral = dht22_measurement.data[2]; + t->decimal = dht22_measurement.data[3]; + // Check sum + uint8_t sum = dht22_measurement.data[0]; + sum += dht22_measurement.data[1]; + sum += dht22_measurement.data[2]; + sum += dht22_measurement.data[3]; + if (sum != dht22_measurement.data[4]) + return 1; + return dht22_measurement.status - 1; +} + +#endif /* CONFIG_IOE_SENSOR_SHT22 */ |