examples: Replace test scripts with practical examples for wsen-hids. (#239)

* refactor(wsen-hids): remove test from examples

* feat(wsen-hids): add simple single read example

* style(wsen-hids): add description for humidity_temp example

* feat(wsen-hids): add a comfort monitoring example

* feat(wsen-hids): add a data logger example

* feat(wsen-hids): add dew point example

* style(wsen-hids): remove french comment

* feat(wsen-hids): add heater to reduce humidity example

* feat(wsen-hids): add low power sampling example

* docs(wsen-hids): add new examples to readme.

* fix(wsen-hids): fix power down issue

* fix(wsen-hids): Add sleep_ms ans forgotten titile line in datalogger example

- Added a warning for the date erasing
- Replace sleep by sleep_ms
- writen head line for csv file

* fix(wsen-hids):  Added sleep_ms in comfort monitor example

* fix(wsen-hids): add sleep_ms to heater demo example

Also put read() after heater disable

* style(wsen-hids): put docstring on multiple line in the example

* fix(wsen-hids): added minimum humidity to ensure math

+ added lint style space

* fix(wsen-hids): Address review feedback on examples.

---------

Co-authored-by: Sébastien NEDJAR <sebastien@nedjar.com>

Author: Charly-sketch

lib/wsen-hids/README.md

@@ -293,16 +293,19 @@ No calibration is required for basic usage.
 
 ---
 
-# Examples
-
-Example scripts are located in:
-
-```
-examples/
-```
-
-Examples include:
-
-* basic one-shot measurements
-* continuous measurement mode
-* driver validation tests
+## Examples
+
+The `examples/` directory provides practical scripts demonstrating how to use the WSEN-HIDS sensor in different scenarios.
+
+### Overview
+
+| Example | Description |
+|--------|------------|
+| `one_shot_mode.py` | Basic one-shot measurements: trigger a measurement and read humidity and temperature on demand |
+| `continuous_mode.py` | Continuous measurement mode: sensor runs continuously and values are read periodically |
+| `humidity_temperature.py` | Beginner-friendly example: perform a single read and print humidity and temperature |
+| `comfort_monitor.py` | Read every 2 seconds and display a comfort indicator (`Dry`, `Comfortable`, `Humid`) based on humidity |
+| `data_logger.py` | Log data every 5 seconds in CSV format (`timestamp, humidity, temperature`) for serial capture |
+| `dew_point.py` | Compute and display dew point using temperature and humidity (Magnus formula) |
+| `heater_demo.py` | Demonstrate the built-in heater: compare readings before and after enabling it |
+| `low_power_sampling.py` | Low-power sampling: one-shot every 10 s with `power_off()` between reads. Requires firmware >= v0.1.0 (#238) |

lib/wsen-hids/examples/comfort_monitor.py

@@ -0,0 +1,30 @@
+"""Loop that reads humidity + temperature every 2s and prints a comfort indicator ("Dry", "Comfortable", "Humid")
+based on humidity thresholds (< 30%, 30-60%, > 60%)"""
+
+from time import sleep_ms
+
+from machine import I2C
+from wsen_hids import WSEN_HIDS
+
+i2c = I2C(1)
+sensor = WSEN_HIDS(i2c)
+
+
+def comfort_label(humidity):
+    if humidity < 30:
+        return "Dry"
+    elif humidity <= 60:
+        return "Comfortable"
+    else:
+        return "Humid"
+
+while True:
+    humidity, temperature = sensor.read_one_shot()
+    comfort = comfort_label(humidity)
+
+    print("Humidity: {:.2f} %RH".format(humidity))
+    print("Temperature: {:.2f} °C".format(temperature))
+    print("Comfort: {}".format(comfort))
+    print()
+
+    sleep_ms(2000)

lib/wsen-hids/examples/data_logger.py

@@ -0,0 +1,42 @@
+"""Log humidity and temperature to DAPLink flash and serial console.
+
+Reads every 5 seconds and writes CSV-formatted output (timestamp,
+humidity, temperature).  Data is stored on the DAPLink flash as
+DATA.CSV and also printed to the serial console.
+
+WARNING: When ERASE_FLASH_ON_START is True, the entire DAPLink flash
+is erased before logging.  Make sure you have backed up any important
+data before enabling erasure.
+"""
+from time import sleep_ms, ticks_diff, ticks_ms
+
+from daplink_flash import DaplinkFlash
+from machine import I2C
+from wsen_hids import WSEN_HIDS
+
+# Set to True to erase the DAPLink flash on startup (DESTRUCTIVE).
+ERASE_FLASH_ON_START = False
+
+i2c = I2C(1)
+sensor = WSEN_HIDS(i2c)
+flash = DaplinkFlash(i2c)
+
+flash.set_filename("DATA", "CSV")
+if ERASE_FLASH_ON_START:
+    flash.clear_flash()
+    sleep_ms(500)
+    print("Flash erased.")
+
+start_ms = ticks_ms()
+
+print("timestamp,humidity,temperature")
+flash.write_line("timestamp,humidity,temperature")
+
+while True:
+    humidity, temperature = sensor.read_one_shot()
+    elapsed_s = ticks_diff(ticks_ms(), start_ms) // 1000
+
+    print("{},{:.2f},{:.2f}".format(elapsed_s, humidity, temperature))
+    flash.write_line("{},{:.2f},{:.2f}".format(elapsed_s, humidity, temperature))
+
+    sleep_ms(5000)

lib/wsen-hids/examples/dew_point.py

@@ -0,0 +1,28 @@
+"""Compute and display the dew point temperature from humidity + temperature using the Magnus formula.
+Useful to understand when condensation might occur."""
+from math import log
+
+from machine import I2C
+from wsen_hids import WSEN_HIDS
+
+i2c = I2C(1)
+sensor = WSEN_HIDS(i2c)
+
+
+def dew_point_celsius(temperature_c, humidity):
+    # Magnus formula
+    a = 17.62
+    b = 243.12  # °C
+
+    # Clamp humidity to a small positive value to avoid log(0) when humidity is 0.0
+    safe_humidity = max(humidity, 0.01)
+    gamma = (a * temperature_c / (b + temperature_c)) + log(safe_humidity / 100.0)
+    dp = (b * gamma) / (a - gamma)
+    return dp
+
+humidity, temperature = sensor.read_one_shot()
+dew_point = dew_point_celsius(temperature, humidity)
+
+print("Humidity: {:.2f} %RH".format(humidity))
+print("Temperature: {:.2f} °C".format(temperature))
+print("Dew point: {:.2f} °C".format(dew_point))