Firmware update.

- Renamed and moved arduino firmware into it's own sketch for arduino
  compiling interface.
- Added esp32 firmware for stringpotentiometer.

2 files changed, 66 insertions, 0 deletions

diff --git a/api_layers/firmware/LabUI_firmware.ino b/api_layers/firmware/arduinoUno.ino
index 8f1b252..8f1b252 100644
--- a/api_layers/firmware/LabUI_firmware.ino
+++ b/api_layers/firmware/arduinoUno.ino
diff --git a/api_layers/firmware/esp32_stringPot/esp32_stringPot.ino b/api_layers/firmware/esp32_stringPot/esp32_stringPot.ino
new file mode 100644
index 0000000..a2efc64
--- /dev/null
+++ b/api_layers/firmware/esp32_stringPot/esp32_stringPot.ino
@@ -0,0 +1,66 @@
+/*
+  LabUI ESP32 Firmware v1.0
+  ─────────────────────────────────────────────────────────────────────────
+  Author: Adam Shatila
+  Co-Author: Christian Kolset
+
+  Upload this sketch to your ESP32 with a TE SP1 spring potensiometer.
+
+  Required library: esp32 by Espressif Systems
+
+  ─────────────────────────────────────────────────────────────────────────
+ */
+
+const int sensorPin = A0;
+const unsigned long sampleInterval = 2000;
+unsigned long lastSampleTime = 0;
+const double lowPassFilter_alpha = 0.00675;
+const unsigned long calibration_factor = 1.07517;
+const long calibration_offset = -267.25;
+float filtered_displacement = 0.0;
+
+void setup() {
+
+  Serial.begin(115200);
+
+  while (!Serial) {
+    delay(10);
+  }
+
+  analogReadResolution(12);
+}
+
+void loop() {
+  unsigned long currentTime = micros();
+
+  if (currentTime - lastSampleTime >= sampleInterval) {
+    lastSampleTime = currentTime;
+
+    uint32_t millivolts = analogReadMilliVolts(sensorPin);
+    float displacement = convert_mV_to_mm(millivolts);
+    filtered_displacement = lowPassFilter(displacement, filtered_displacement, lowPassFilter_alpha);
+    float volts = filtered_displacement;
+
+    // Output the voltage to the serial monitor with 3 decimal places
+    //Serial.print(displacement, 3);
+    //Serial.print(",   ");
+    Serial.println(filtered_displacement, 3);
+    //Serial.println(millivolts);
+  }
+}
+
+float convert_mV_to_mm(float mVolts){
+  // Reads mV from sensor and output in mm from lower limit
+  float voltage = mVolts / 1000.0;
+  float raw_val = voltage * (635.0 / 2.863);
+  //float inverted_val = 650.0 - raw_val;
+  //float volts = inverted_val * (635.0 / 637.0);
+  float volts = raw_val * (635.0 / 637.0);
+
+  return calibration_factor * volts + calibration_offset;
+}
+
+float lowPassFilter(float newSample, float prevOutput, float alpha) {
+  // Simple exponential low-pass filter (EMA) formula
+  return alpha * newSample + (1.0 - alpha) * prevOutput;
+}