First working code for HC-SR04 sensor.

2022-12-30 23:03:38 -05:00
parent 58a40379a9
commit 551e8f9e30
4 changed files with 141 additions and 108 deletions
--- a/pico_funcs.py
+++ b/pico_funcs.py
@@ -0,0 +1,68 @@
+import machine
+import network
+import wifi_config
+import time
+
+'''
+pico_funcs: Helper functions for things the pico can do.
+'''
+
+def read_cpu_temp():
+    """
+        If you print the value of the temperature value you are going to get an integer number between 0 and 65535.
+        So, we have to convert this value either to the Celsius degree scales.
+
+        The temperature sensor works by delivering a voltage to the ADC4 pin that is proportional to the temperature.
+        From the datasheet, a temperature of 27 degrees Celsius delivers a voltage of 0.706 V.
+        With each additional degree the voltage reduces by 1.721 mV or 0.001721 V.
+        The first step in converting the 16-bit temperature is to convert it back to volts, which is done based on the 3.3 V maximum voltage used by the Pico board.
+        ref: https://how2electronics.com/read-temperature-sensor-value-from-raspberry-pi-pico/
+    """
+    cpu_temp_conversion_factor = 3.3 / 65535
+    cpu_temp_sensor = machine.ADC(4)
+    reading = cpu_temp_sensor.read_u16() * cpu_temp_conversion_factor
+    temperature_c = 27 - (reading - 0.706) / 0.001721
+    temperature_f = temperature_c * 9/5. + 32.0
+    return temperature_f
+
+def wlan_up(wlan):
+    wlan.active(True)
+    wlan.connect(wifi_config.HOME_WIFI_SSID, wifi_config.HOME_WIFI_PWD)
+    
+    # Wait for connect or fail
+    max_wait = 10
+    while max_wait > 0:
+        if wlan.status() < 0 or wlan.status() >= 3:
+            break
+        max_wait -= 1
+        time.sleep(1)
+
+    if max_wait == 0:
+        return None
+    
+    ifconfig = wlan.ifconfig()
+    return ifconfig
+
+def led_error_code(led, error_code: int):
+    """Blink LED for a given error code (int). error code == number of times to blink"""
+    
+    # Run a quick 'start error code sequence'
+    # So we know when LED error sequence starts
+    start_sequence_counter = 0
+    while start_sequence_counter < 3:
+        led.value(True)
+        time.sleep(0.1)
+        led.value(False)
+        time.sleep(0.1)
+        start_sequence_counter += 1
+    
+    # Run real error code sequence
+    blink_counter = 0
+    while blink_counter < error_code:
+        time.sleep(1)
+        led.value(True)
+        time.sleep(1)
+        led.value(False)
+        blink_counter += 1
+    # Make sure to turn off LED when this subroutine finished
+    led.value(False)