SDI10809 RE success

extensions/platformio/IOT_Scale/src/main.cpp

@@ -1,32 +1,112 @@
 #include <Arduino.h>
-#include "HX711.h"
 
-const int LOADCELL_SCK_PIN = 3;
-const int LOADCELL_DOUT_PIN = 2;
+const int SCLK_PIN = 1;
+const int DOUT_PIN = 2;
 
-const long LOADCELL_OFFSET = 0;
-const long LOADCELL_DIVIDER = 0;
+long tareOffset = 0;
+float calibrationFactor = 74.17; //1.0 by default, callibrated by placing 796 weight and callibrating
+float smoothedWeight = 0.0;
+float alpha = 0.15; // Adjustment: 0.05 (very smooth/slow) to 0.3 (jumpy/fast)
 
-HX711 scale;
+long readSD10809() {
+    long data = 0;
+    
+    // Wait for DRDY to go LOW 
+    uint32_t timeout = millis();
+    while (digitalRead(DOUT_PIN) == HIGH) {
+        if (millis() - timeout > 100) return -1; // 20Hz rate is 50ms 
+    }
+
+    // Read 24-bit ADC result [cite: 158, 160]
+    for (int i = 0; i < 24; i++) {
+        digitalWrite(SCLK_PIN, HIGH);
+        delayMicroseconds(1); 
+        data = (data << 1) | digitalRead(DOUT_PIN);
+        digitalWrite(SCLK_PIN, LOW);
+        delayMicroseconds(1);
+    }
+
+    // Send 3 extra pulses (Total 27) to keep Channel A at 128x Gain [cite: 152, 161]
+    for (int i = 0; i < 3; i++) {
+        digitalWrite(SCLK_PIN, HIGH);
+        delayMicroseconds(1);
+        digitalWrite(SCLK_PIN, LOW);
+        delayMicroseconds(1);
+    }
+
+    // Handle 24-bit Two's Complement sign extension [cite: 108]
+    if (data & 0x800000) data |= 0xFF000000;
+    
+    return data;
+}
+
+long getAverageReading(int samples) {
+    long sum = 0;
+    int count = 0;
+    while (count < samples) {
+        long val = readSD10809();
+        if (val != -1) {
+            sum += val;
+            count++;
+        }
+    }
+    return sum / samples;
+}
+
+void tare() {
+    Serial.println("Taring... keep scale still.");
+    tareOffset = getAverageReading(20);
+    Serial.print("New Offset: ");
+    Serial.println(tareOffset);
+}
+
+void calibrate(float knownWeightGrams) {
+    long currentRaw = getAverageReading(20);
+    calibrationFactor = (float)(currentRaw - tareOffset) / knownWeightGrams;
+    Serial.print("Calibration Factor set to: ");
+    Serial.println(calibrationFactor);
+}
 
 void setup() {
-  Serial.begin(115200);
-  while(!Serial);
-
-  Serial.println("Remove all weight from the scale.");
-  delay(2000);
-  scale.set_scale();
-  scale.tare();
-  Serial.println("Tare complete. Place a known weight on the scale.");
+    Serial.begin(115200);
+    pinMode(SCLK_PIN, OUTPUT);
+    pinMode(DOUT_PIN, INPUT);
+    
+    // Give the chip time to stabilize (2 cycles for SD10809) [cite: 142]
+    delay(500); 
+    tare();
 }
 
 void loop() {
-  if (scale.is_ready()) {
-    long reading = scale.get_units(10);
-    Serial.print("Raw Value: ");
-    Serial.println(reading);
-  } else {
-    Serial.println("HX711 not found.");
-  }
-  delay(1000);
+    long raw = readSD10809();
+    
+    if (raw != -1) {
+        // 1. Calculate current instantaneous weight
+        float currentWeight = (raw - tareOffset) / calibrationFactor;
+
+        // 2. Apply EMA Filter
+        smoothedWeight = (alpha * currentWeight) + (1.0 - alpha) * smoothedWeight;
+
+        // 3. Optional: "Auto-Zero" or Snap-to-Zero
+        // If the weight is within 0.05g of zero, just show 0.00
+        float displayWeight = smoothedWeight;
+        if (abs(displayWeight) < 0.05) {
+            displayWeight = 0.00;
+        }
+
+        Serial.print("Weight: ");
+        Serial.print(displayWeight, 2);
+        Serial.println(" g");
+    }
+
+    // Example trigger for calibration via Serial
+    if (Serial.available()) {
+        char c = Serial.read();
+        if (c == 't') {
+          tare();
+        }
+        if (c == 'c') {
+          calibrate(796);
+        }
+    }
 }