DHT11 — pymcu.drivers.dht11

from pymcu.drivers.dht11 import DHT11

Temperature and humidity sensor driver using the DHT11 1-wire protocol.

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class DHT11

DHT11(pin: str)

Binds the driver to a GPIO pin at compile time. The pin must support both output (for the start signal) and input (for reading the response).

Methods

Method	Return type	Description
read() -> uint16	uint16	Read temperature and humidity

Return value encoding

The 16-bit return value packs both readings:

Bits	Contents
High byte (15–8)	Humidity (0–100 %)
Low byte (7–0)	Temperature in Celsius (0–50 °C)
0xFFFF	Read error: no response or checksum failure

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Example

from pymcu.drivers.dht11 import DHT11
from pymcu.hal.uart import UART
from pymcu.time import delay_ms
from pymcu.types import uint8, uint16

def main():
    sensor = DHT11("PD4")
    uart = UART(9600)

    while True:
        result: uint16 = sensor.read()
        if result != 0xFFFF:
            humidity: uint8 = result >> 8
            temp: uint8 = result & 0xFF
            uart.write_str("H=")
            uart.print_byte(humidity)
            uart.write_str(" T=")
            uart.print_byte(temp)
            uart.println("C")
        delay_ms(2000)

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Notes

• The DHT11 requires a minimum 2-second interval between reads. Calling read() more frequently will return stale data or a checksum error.

• The 1-wire protocol uses precise delay_us() timing. Avoid enabling ISRs that may fire during a read — they will corrupt the timing and cause checksum failures.

• The driver is architecture-independent. Pulse measurement delegates to pymcu.drivers._dht11.avr (or the appropriate arch sub-module) via __CHIP__ dispatch.