Implementing static load test

include/LoadCells.h

@@ -0,0 +1,3 @@
+struct LoadCells{
+    double lc0, lc1, lc2, lc3 = 0.0;
+};

platformio.ini

@@ -12,3 +12,4 @@
 platform = teensy
 board = teensy41
 framework = arduino
+lib_deps = bogde/HX711@^0.7.4

src/main.cpp

@@ -1,9 +1,171 @@
 #include <Arduino.h>
+#include "HX711.h"
+#include "LoadCells.h"
+#include "SD.h"
+
+LoadCells State;
+
+HX711 lc0;
+HX711 lc1;
+HX711 lc2;
+HX711 lc3;
+
+void write2CSV(struct LoadCells &);
+void initFile();
+
+void read_lc0();
+void read_lc1();
+void read_lc2();
+void read_lc3();
+
+const int lc_clock = 23;
+const int pin_lc0 = 14;
+const int pin_lc1 = 15;
+const int pin_lc2 = 19;
+const int pin_lc3 = 20;
+
+double lc0Offset = 0.0;
+double lc1Offset = 0.0;
+double lc2Offset = 0.0;
+double lc3Offset = 0.0;
+
+const int chipSelect = BUILTIN_SDCARD;
+File dataFile;
 
 void setup() {
   // put your setup code here, to run once:
+  pinMode(lc_clock, INPUT);
+
+  // Configure load cell data pins as inputs
+  pinMode(pin_lc0, INPUT);
+  pinMode(pin_lc1, INPUT);
+  pinMode(pin_lc2, INPUT);
+  pinMode(pin_lc3, INPUT);
+  lc0.begin(pin_lc0, lc_clock);
+  lc1.begin(pin_lc1, lc_clock);
+  lc2.begin(pin_lc2, lc_clock);
+  lc3.begin(pin_lc3, lc_clock);
+
+  lc0.set_scale();
+  lc1.set_scale();
+  lc2.set_scale();
+  lc3.set_scale();
+
+  lc0.tare(50);
+  lc1.tare(50);
+  lc2.tare(50);
+  lc3.tare(50);
+
+  // Attach ISRs to load cell data pins to read data when available
+  attachInterrupt(digitalPinToInterrupt(pin_lc0), read_lc0, LOW);
+  attachInterrupt(digitalPinToInterrupt(pin_lc1), read_lc1, LOW);
+  attachInterrupt(digitalPinToInterrupt(pin_lc2), read_lc2, LOW);
+  attachInterrupt(digitalPinToInterrupt(pin_lc3), read_lc3, LOW);
+
+  Serial.println("Load Cells Initialized");
+  Serial.println("Calibrating");
+
+  // Load Cell Tare
+  double lc0Tot = 0.0;
+  double lc1Tot = 0.0;
+  double lc2Tot = 0.0;
+  double lc3Tot = 0.0;
+
+  for (int i = 0; i < 50; i++) {
+    lc0Tot += State.lc0;
+    lc1Tot += State.lc1;
+    lc2Tot += State.lc2;
+    lc3Tot += State.lc3;
+    delay(50);
+  }
+
+  lc0Offset = lc0Tot / 50.0;
+  lc1Offset = lc1Tot / 50.0;
+  lc2Offset = lc2Tot / 50.0;
+  lc3Offset = lc3Tot / 50.0;
+
+  Serial.println(lc0Tot);
+  Serial.println(lc1Tot);
+  Serial.println(lc2Tot);
+  Serial.println(lc3Tot);
+
+  Serial.println("Load Cells Tared");
+
+  // Initializes State variables
+  State.lc0 = lc0.get_value();
+  State.lc1 = lc1.get_value();
+  State.lc2 = lc2.get_value();
+  State.lc3 = lc3.get_value();
 }
 
 void loop() {
   // put your main code here, to run repeatedly:
-}
+  write2CSV(State);
+  delay(20);
+}
+
+void read_lc0() { State.lc0 = lc0.get_value() - lc0Offset; }
+void read_lc1() { State.lc1 = lc1.get_value() - lc1Offset; }
+void read_lc2() { State.lc2 = lc2.get_value() - lc2Offset; }
+void read_lc3() { State.lc3 = lc3.get_value() - lc3Offset; }
+
+void write2CSV(LoadCells &State) {
+
+  dataFile.print(String(State.lc0, 5));
+  dataFile.print(",");
+  dataFile.print(String(State.lc1, 5));
+  dataFile.print(",");
+  dataFile.print(String(State.lc2, 5));
+  dataFile.print(",");
+  dataFile.print(String(State.lc3, 5));
+
+  dataFile.close();
+}
+
+void initFile(){
+  Serial.print("Initializing SD card...");
+  // see if the card is present and can be initialized:
+  if (!SD.begin(chipSelect)) {
+    Serial.println("Card failed, or not present. \n\nABORTING SIMULATION");
+  }
+  Serial.println("Card initialized.");
+
+  int i = 1;
+  const char *fileName;
+
+  if (SD.exists("simOut.csv")) {
+    while (i > 0.0) {
+      fileName = ("simOut_" + String(i) + ".csv").c_str();
+
+      if (!SD.exists(fileName)) {
+        // Open simOut_i.csv
+        dataFile = SD.open(fileName, FILE_WRITE);
+
+        if (dataFile) {
+          Serial.println("File successfully opened!");
+
+        } else {
+          // if the file didn't open, print an error:
+          Serial.println("Error opening output file. \n\nABORTING SIMULATION");
+        }
+        i = 0.0;
+
+      } else {
+        i++;
+      }
+    }
+  } else {
+    // Open simOut.csv
+    dataFile = SD.open("simOut.csv", FILE_WRITE);
+    if (dataFile) {
+      Serial.println("File successfully opened!");
+
+    } else {
+      // if the file didn't open, print an error:
+      Serial.println("Error opening output file. \n\nABORTING SIMULATION");
+    }
+  }
+  dataFile.println(
+      "lc0,lc1,lc2,lc3");
+}
+