docs: Expand README for hts221 driver.

Author: Charly-sketch

lib/hts221/README.md

@@ -1,9 +1,178 @@
-# MicroPython Driver for the HTS221 Humidity Sensor
+# HTS221 MicroPython Driver
 
-This library is a port of the [MicroPython Driver for the HTS221 Humidity Sensor](https://github.com/jposada202020/MicroPython_HTS221/tree/master).
+MicroPython driver for the **STMicroelectronics HTS221** humidity and temperature sensor.
 
-The examples could be easily tested with [mpremote](https://docs.micropython.org/en/latest/reference/mpremote.html) with the following command :
+The HTS221 provides:
 
-```sh
- mpremote mount . run examples/humidity.py
+* **Relative humidity (%)**
+* **Temperature (°C)**
+
+This driver offers a simple and complete API for configuration, measurement, calibration, and power management using **I²C**.
+
+## Features
+
+* I²C communication
+* Device identification (`WHO_AM_I`)
+* Relative humidity measurement
+* Temperature measurement
+* One-shot measurement mode
+* Continuous measurement mode
+* Configurable output data rate (ODR)
+* Configurable averaging
+* Data-ready status flags
+* Power management (power on/off, reboot)
+* Built-in factory calibration usage
+* User temperature calibration:
+  * offset correction
+  * two-point calibration
+
+## I²C Address
+
+* Default address: **0x5F** 
+
+## Basic Usage
+
+```python
+from machine import I2C
+from hts221 import HTS221
+
+# Initialize I2C
+i2c = I2C(1)
+
+# Initialize sensor
+sensor = HTS221(i2c)
+
+# Read values
+humidity = sensor.humidity()
+temperature = sensor.temperature()
+
+print("Humidity:", humidity, "%")
+print("Temperature:", temperature, "°C")
+
+# Read both at once
+h, t = sensor.read()
+```
+
+## API
+
+### Device Information
+
+```python
+device_id()
+```
+
+Returns the sensor device ID (`WHO_AM_I` register).
+
+### Data Readiness
+
+```python
+data_ready()
+temperature_ready()
+humidity_ready()
 ```
+
+* `data_ready()` → both humidity and temperature available
+* `temperature_ready()` → temperature available
+* `humidity_ready()` → humidity available
+
+### Measurements
+
+```python
+temperature()
+humidity()
+read()
+read_one_shot()
+```
+
+* `temperature()` → temperature in °C
+* `humidity()` → relative humidity in %
+* `read()` → `(humidity, temperature)`
+* `read_one_shot()` → performs a one-shot measurement and returns `(humidity, temperature)`
+
+### One-Shot Mode
+
+```python
+trigger_one_shot()
+```
+
+Triggers a single measurement (used internally by `read_one_shot()`).
+
+### Configuration
+
+```python
+get_odr()
+set_odr(odr)
+set_continuous(odr)
+```
+
+* `get_odr()` → returns current output data rate
+* `set_odr(odr)` → set ODR (0 = one-shot mode)
+* `set_continuous(odr)` → enable continuous mode (ODR ≠ 0)
+
+### Averaging Configuration
+
+```python
+get_av()
+set_av(av)
+```
+
+Controls internal averaging for humidity and temperature.
+
+### Power Management
+
+```python
+power_on()
+power_off()
+reboot()
+```
+
+* `power_on()` → enable sensor
+* `power_off()` → disable sensor
+* `reboot()` → reload calibration data and reboot memory
+
+### Temperature Calibration
+
+```python
+set_temp_offset(offset_c)
+calibrate_temperature(ref_low, measured_low, ref_high, measured_high)
+```
+
+* `set_temp_offset(offset_c)`
+  Apply a simple temperature offset correction.
+
+* `calibrate_temperature(...)`
+  Perform a **two-point calibration**:
+
+  * improves accuracy
+  * adjusts both gain and offset 
+
+## Examples
+
+| File          | Description                            |
+| ------------- | -------------------------------------- |
+| `humidity.py` | Basic humidity and temperature reading |
+
+Run with:
+
+```bash
+mpremote mount lib/htss221 run examples/htss221/examples/humidity.py
+```
+
+---
+
+## Notes
+
+* The driver uses **factory calibration data** stored in the sensor.
+* Temperature can be further corrected using:
+
+  * `set_temp_offset()` (simple correction)
+  * `calibrate_temperature()` (recommended for precision)
+* In one-shot mode, the driver automatically waits for data readiness.
+* In power-down or one-shot mode, measurements trigger automatically when needed.
+
+---
+
+## Source
+
+This library is a port of:
+[https://github.com/jposada202020/MicroPython_HTS221/tree/master](https://github.com/jposada202020/MicroPython_HTS221/tree/master)