From ded133e35f80cb3eb8c28ae414cc412f290d898e Mon Sep 17 00:00:00 2001
From: =?utf8?q?Luk=C3=A1=C5=A1=20Ji=C5=99i=C5=A1t=C4=9B?=
 <jiriste@icpf.cas.cz>
Date: Wed, 23 Oct 2024 10:43:22 +0200
Subject: [PATCH] Implement PressureSensor class and use it in main

---
 Makefile           |  3 ++-
 PressureSensor.h   | 24 ++++++++++++++++++++++++
 PressureSensor.ino | 28 ++++++++++++++++++++++++++++
 Servomatic.ino     | 26 ++++++--------------------
 4 files changed, 60 insertions(+), 21 deletions(-)
 create mode 100644 PressureSensor.h
 create mode 100644 PressureSensor.ino

diff --git a/Makefile b/Makefile
index 31ea10c..a714226 100644
--- a/Makefile
+++ b/Makefile
@@ -11,7 +11,8 @@ ifneq ("$(wildcard .verbose)","")
 	MAINCMD += --verbose
 endif
 
-SRCS :=	Servomatic.ino	\
+SRCS :=	Servomatic.ino		\
+		PressureSensor.ino	\
 
 
 NAME := Servomatic
diff --git a/PressureSensor.h b/PressureSensor.h
new file mode 100644
index 0000000..1a849ae
--- /dev/null
+++ b/PressureSensor.h
@@ -0,0 +1,24 @@
+#ifndef PRESSURESENSOR_H
+# define PRESSURESENSOR_H
+
+class PressureSensor
+{
+	private:
+		typedef int pin;
+
+		const pin	m_analog_pin;
+
+		static double	signal_to_pressure(int ad_signal);
+
+	public:
+		PressureSensor() = delete;
+		PressureSensor(pin analog_pin);
+		PressureSensor(const PressureSensor &other) = delete;
+		~PressureSensor();
+
+		PressureSensor	&operator=(const PressureSensor &other) = delete;
+
+		double	get_pressure();
+};
+
+#endif // PRESSURESENSOR_H
diff --git a/PressureSensor.ino b/PressureSensor.ino
new file mode 100644
index 0000000..eae698e
--- /dev/null
+++ b/PressureSensor.ino
@@ -0,0 +1,28 @@
+#include "PressureSensor.h"
+
+PressureSensor::PressureSensor(pin analog_pin)
+	: m_analog_pin{analog_pin}
+{
+}
+
+PressureSensor::~PressureSensor()
+{
+}
+
+// The Pressure sensor gives a current I/mA = 4 + 1.6 * p/bar with p absolute
+// pressure from 0 bar to 10 bar (giving current between 4 mA and 20 mA).
+// This current is passed through a 240 Ω resistor giving a voltage between
+// 0.96 V and 4.8 V. Thus U/V = 0.96 + 0.384 * p/bar.
+// Using the 10-bit AD convertor we get a signal from 0 to 2^10 - 1 on the range
+// of 0 V to 5 V.
+// Hence signal = (2^10 - 1) / (5 V) * U = 1023 / 5 * (0.96 + 0.384 * p/bar)
+// And p/bar = 1 / 0.384 * (5 / (2^10 - 1) * signal - 0.96)
+double	PressureSensor::signal_to_pressure(int ad_signal)
+{
+	return (((static_cast<double>(ad_signal) * 5) / (2 << 10 - 1) - 0.96) / 0.384);
+}
+
+double	PressureSensor::get_pressure()
+{
+	return (signal_to_pressure(analogRead(m_analog_pin)));
+}
diff --git a/Servomatic.ino b/Servomatic.ino
index 684a35c..466b06a 100644
--- a/Servomatic.ino
+++ b/Servomatic.ino
@@ -1,29 +1,15 @@
-void	wait_for_button(int	trigger)
-{
-	int	read_val;
-
-	read_val = digitalRead(7);
-	while (read_val != trigger)
-	{
-		read_val = digitalRead(7);
-		delay(10);
-	}
-}
+#include "PressureSensor.h"
 
 int	main()
 {
+	PressureSensor	test{A5};
+
 	init();
-	pinMode(7, INPUT_PULLUP);
-	pinMode(4, OUTPUT);
-	digitalWrite(4, LOW);
+	Serial.begin(9600);
 	while (1)
 	{
-		wait_for_button(LOW);
-		digitalWrite(4, HIGH);
-		wait_for_button(HIGH);
-		wait_for_button(LOW);
-		digitalWrite(4, LOW);
-		wait_for_button(HIGH);
+		Serial.println(test.get_pressure());
+		delay(500);
 	}
 	return (0);
 }
-- 
2.30.2