芯片工作原理

https://www.iotword.com/12030.html
https://wenku.baidu.com/view/218a2fe62bea81c758f5f61fb7360b4c2e3f2a13.html?_wkts_=1708705733551&bdQuery=am2305%E8%BF%9C%E7%A6%BB

硬件连接

vcc
gnd
gpio：GPIO3_A1 数据线要外接4.7k上拉电阻

修改设备树

humidity_sensor {compatible = "dht11";gpios = <&gpio3 RK_PA1 GPIO_ACTIVE_HIGH>;
}&pinctrl {sensor {sensor_gpio: sensor-gpio {rockchip,pins =<3 RK_PA1 RK_FUNC_GPIO &pcfg_pull_up>;};};
};

使能驱动

/kernel/drivers/iio/humidity/dht11.c

适配am2305

am2305芯片对时序要求不同，需要将dht11.c驱动中主机拉低时间进行修改。
#define DHT11_START_TRANSMISSION_MIN	800  /* us */
#define DHT11_START_TRANSMISSION_MAX	1000  /* us */

读取温湿度数据