New branch

data-logger.py

@@ -0,0 +1,60 @@
+from serial import Serial
+
+from datetime import datetime
+import matplotlib.pyplot as plt
+import matplotlib.cbook as cbook
+import numpy as np
+import csv
+
+import atexit
+
+
+port = "COM4"
+baud_rate = 115200
+
+@atexit.register
+def plot_data():
+    # plot the data once the is done running
+
+    if(os.path.exists("sensor-data.csv")):
+        print("File found")
+    else:
+        print("File does not exist")
+
+    # read file
+    arr = np.loadtxt("sensor-data.csv", delimiter=",", unpack=True)
+
+    plt.plot(arr[0], arr[1])
+    plt.title("Unfiltered x acceleration")
+    plt.xlabel("Time (ms)")
+    plt.ylabel("X acceleration (m/s^2)")
+
+    plt.show()
+
+
+def read_serial_data():
+
+    # create Serial object
+    serial_port = Serial(port, baud_rate)
+
+    # csv writer object
+    output_file = open("sensor-data.csv", "w", newline="")
+    output_writer = csv.writer(output_file)
+
+    # register function to run when the function exits
+    # atexit.register(plot_data)
+
+    while(True):
+        now = datetime.now()
+        current_time = now.timestamp()
+
+        # read x acceleration into a csv file
+        data = serial_port.readline()
+
+        if data:
+            data = float(data)
+
+        output_writer.writerow([current_time, data])
+
+
+read_serial_data()

graph.py

@@ -0,0 +1,24 @@
+import matplotlib.pyplot as plt
+import matplotlib.cbook as cbook
+import numpy as np
+import os
+
+def plot_data():
+    # plot the data once the is done running
+
+    if(os.path.exists("sensor-data.csv")):
+        print("File found")
+    else:
+        print("File does not exist")
+
+    # read file
+    arr = np.loadtxt("sensor-data.csv", delimiter=",", unpack=True)
+
+    plt.plot(arr[0], arr[1])
+    plt.title("Unfiltered x acceleration")
+    plt.xlabel("Time (ms)")
+    plt.ylabel("X acceleration (m/s^2)")
+
+    plt.show()
+
+plot_data()

include/defs.h

@@ -0,0 +1,45 @@
+#ifndef DEFS_H
+#define DEFS_H
+
+/* debug enable for use during testing */
+#define DEBUG 1
+
+#if DEBUG == 1
+
+#define debug(x) Serial.print(x)
+#define debugln(x) Serial.println(x)
+#define debugf(x, y) Serial.printf(x, y)
+
+#else
+
+#define debug(x)
+#define debugln(x)
+#define debugf(x, y)
+
+#endif
+
+/* timing constant */
+#define SETUP_DELAY 300
+#define TASK_DELAY 10
+
+/* flight constants */
+#define EJECTION_HEIGHT 1000 // eject at 1000m AGL
+#define SEA_LEVEL_PRESSURE 101325 // Assume the sea level pressure is 101325 Pascals - this can change with weather
+#define ALTITUDE_OFFSET 1500 /* this value is the altitude at rocket launch site */
+
+/* tasks constants */
+#define STACK_SIZE 2048
+#define ALTIMETER_QUEUE_LENGTH 10 // todo: change to 2 items
+#define GYROSCOPE_QUEUE_LENGTH 10
+#define FILTERED_DATA_QUEUE_LENGTH 10
+
+/* MQTT constants */
+const char* MQTT_SERVER = "192.168.1.100";
+#define MQTT_BUFFER_SIZE 300
+#define MQTT_PORT 1883
+
+/* WIFI credentials */
+const char* SSID = "onboard";
+const char* PASSWORD = "123456789";
+
+#endif

include/kalman.cpp

@@ -0,0 +1,79 @@
+#include <BasicLinearAlgebra.h>
+#include "defs.h"
+#include "kalman.h"
+
+float q = 0.0001;
+float T = 0.1;
+
+// The system dynamics
+BLA::Matrix<3, 3> A = {1.0, 0.1, 0.005,
+                       0, 1.0, 0.1,
+                       0, 0, 1.0};
+
+// Relationship between measurement and states
+BLA::Matrix<2, 3> H = {1.0, 0, 0,
+                       0, 0, 1.0};
+
+// Initial posteriori estimate error covariance
+BLA::Matrix<3, 3> P = {1, 0, 0,
+                       0, 1, 0,
+                       0, 0, 1};
+
+// Measurement error covariance
+BLA::Matrix<2, 2> R = {0.25, 0,
+                       0, 0.75};
+
+// Process noise covariance
+BLA::Matrix<3, 3> Q = {q, q, q,
+                       q, q, q,
+                       q, q, q};
+
+// Identity Matrix
+BLA::Matrix<3, 3> I = {1, 0, 0,
+                       0, 1, 0,
+                       0, 0, 1};
+
+BLA::Matrix<3, 1> x_hat = {1500.0,
+                           0.0,
+                           0.0};
+
+BLA::Matrix<2, 1> Y = {0.0,
+                       0.0};
+
+
+/* This filters our altitude and acceleration values */
+struct Filtered_Data filterData(float x_acceleration){
+    /* this struct will store the filtered data values */
+    struct Filtered_Data filtered_values;
+
+    // Measurement matrix
+    BLA::Matrix<2, 1> Z = {0, x_acceleration};
+
+    // Predicted state estimate
+    BLA::Matrix<3, 1> x_hat_minus = A * x_hat;
+
+    // Predicted estimate covariance
+    BLA::Matrix<3, 3> P_minus = A * P * (~A) + Q;
+
+    // Kalman gain
+    BLA::Matrix<2, 2> con = (H * P_minus * (~H) + R);
+    BLA::Matrix<3, 2> K = P_minus * (~H) * Invert(con);
+
+    // Measurement residual
+    Y = Z - (H * x_hat_minus);
+
+    // Updated state estimate
+    x_hat = x_hat_minus + K * Y;
+
+    // Updated estimate covariance
+    P = (I - K * H) * P_minus;
+    Y = Z - (H * x_hat_minus);
+
+    filtered_values.x_acceleration = x_hat(2);
+
+    // return_val.displacement = x_hat(0);
+    // return_val.velocity = x_hat(1);
+    // return_val.acceleration = x_hat(2);
+
+    return filtered_values;
+}

include/kalman.h

@@ -0,0 +1,12 @@
+
+#pragma once
+
+/* define struct to hold filtered data*/
+struct Filtered_Data{
+    float x_acceleration;
+};
+
+
+/* this function returns Kalman-filtered data */
+struct Filtered_Data filterData(float);
+

include/sensors.cpp

@@ -0,0 +1,4 @@
+//
+// Created by Edwin Mwiti on 3/6/2023.
+//
+

include/sensors.h

@@ -0,0 +1,11 @@
+//
+// Created by Edwin Miwiri on 3/6/2023.
+//
+
+#ifndef SENSORS_H
+#define SENSORS_H
+
+void initialize_gyroscope();
+void initialize_altimeter();
+
+#endif 

platformio.ini

@@ -11,4 +11,13 @@
 [env:nodemcu-32s]
 platform = espressif32
 board = nodemcu-32s
+monitor_speed=115200
 framework = arduino
+; upload_port = COM4
+lib_deps = 
+	adafruit/Adafruit MPU6050@^2.2.4
+	adafruit/Adafruit Unified Sensor@^1.1.7
+	adafruit/Adafruit BMP085 Library @ ^1.2.2
+	tomstewart89/BasicLinearAlgebra@^3.7
+	Knolleary/PubSubClient@^2.8
+