Add Ability to Set Individual Thresholds For Each Photoresistor

LiBoard.cpp

@@ -71,6 +71,14 @@ unsigned long long LiBoard::getBinaryBoard(unsigned short threshold) {
 	return binBoard;
 }
 
+unsigned long long LiBoard::getBinaryBoard(unsigned short *thresholds) {
+	getData();
+	unsigned long long binBoard = 0;
+	for (unsigned char i = 0; i<64; ++i)
+		binBoard |= (((unsigned long long) (values[i]<=thresholds[i])) << i);
+	return binBoard;
+}
+
 bool LiBoard::getSquareOccupancy(unsigned char file, unsigned char rank, long long binaryBoard) {
 	return (bool)((binaryBoard>>getIndex(file, rank))&1);
 }

LiBoard.h

@@ -30,6 +30,7 @@ class LiBoard {
 	void getData();
 	unsigned char getIndex(unsigned char file, unsigned char rank);
 	unsigned long long getBinaryBoard(unsigned short threshold);
+	unsigned long long getBinaryBoard(unsigned short *thresholds);
 	bool getSquareOccupancy(unsigned char file, unsigned char rank, long long binaryBoard);
 private:
 	void clockPulse();

README.md

@@ -7,3 +7,45 @@ Clone this repo into `YOUR_ARDUINO_FOLDER/libraries/`.
 ## Usage
 If you're just interested in using the board with a script or the app, you'll want
 to run the `serial_binboard` sketch from the library's examples folder.
+
+## Thresholds
+Each photoresistor requires a threshold value which triggers when each square is occupied or not. There are two options you can use to set the threshold values for each square.
+
+### Setting Threshold Mode
+By default, Liboard is configured to use the Global threshold mode. If you want to change it Per-Square thresholds, then edit the following variable:
+
+``` C
+// !!! choose mode: 1 = global single value, 0 = per-square array !!!
+#define USE_GLOBAL_THRESHOLD 1
+```
+
+### Option 1 - Global Threshold
+Global Threshold mode applies the same threshold value to every photoresistor. If you need to change the sensitivity of the photoresistors, change the value of this variable:
+```C
+// Option 1 - Global Threshold (Applies to all photoresistors)
+unsigned short THRESHOLD = 100;
+```
+
+### Option 2 - Per-square Thresholds
+You can also set individual thresholds for each photoresisor. This is useful if not all your photoresistors are the same type. Per-square thresholds also has more accuracy. You can adjust each square threshold individually by editing each number.
+```C
+// Option 2 - Per-square threshold (Applies to each individual photoresistor)
+unsigned short THRESHOLD[64] = {
+  // A1..H1
+  150, 150, 150, 150, 150, 150, 150, 150,
+  // A2..H2
+  150, 150, 150, 150, 150, 150, 150, 150,
+  // A3..H3
+  100, 100, 100, 100, 100, 100, 100, 100,
+  // A4..H4
+  100, 100, 100, 100, 100, 100, 100, 100,
+  // A5..H5
+  600, 600, 600, 600, 600, 600, 600, 600,
+  // A6..H6
+  600, 600, 600, 600, 600, 600, 600, 600,
+  // A7..H7
+  300, 300, 300, 300, 300, 300, 300, 300,
+  // A8..H8
+  300, 300, 300, 300, 300, 300, 300, 300
+};
+```

examples/serial_binboard/serial_binboard.ino

@@ -14,8 +14,39 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>. */
 
 #include "LiBoard.h"
+#include <string.h>
 
-const unsigned short THRESHOLD = 100;
+// !!! choose mode: 1 = global single value, 0 = per-square array !!!
+#define USE_GLOBAL_THRESHOLD 0
+
+#if USE_GLOBAL_THRESHOLD 
+// Option 1 - Global Threshold (Applies to all photoresistors)
+unsigned short THRESHOLD = 100;
+
+#else
+// Option 2 - Per-square threshold (Applies to each individual photoresistor)
+unsigned short THRESHOLD[64] = {
+  // A1..H1
+  300, 300, 300, 300, 300, 300, 300, 300,
+  // A2..H2
+  300, 300, 300, 300, 300, 300, 300, 300,
+  // A3..H3
+  100, 100, 100, 100, 100, 100, 100, 100,
+  // A4..H4
+  100, 100, 100, 100, 100, 100, 100, 100,
+  // A5..H5
+  600, 600, 600, 600, 600, 600, 600, 600,
+  // A6..H6
+  600, 600, 600, 600, 600, 600, 600, 600,
+  // A7..H7
+  300, 300, 300, 300, 300, 300, 300, 300,
+  // A8..H8
+  300, 300, 300, 300, 300, 300, 300, 300,
+};
+#endif
+
+bool calibrating = false;
+bool quiet = false;
 
 LiBoard board = LiBoard();
 unsigned long long lastBinBoard = 0;
@@ -26,15 +57,102 @@ void writeBinaryBoard(unsigned long long binBoard) {
     Serial.write((unsigned char)(binBoard>>(8*(7-i))));
 }
 
+// print a single CSV snapshot of raw ADC values (A1..H8 in LiBoard order)
+void printRawSnapshotCSV() {
+  board.getData();                   // fills board.values[0..63]
+  for (int i = 0; i < 64; ++i) {
+    Serial.print(board.values[i]);
+    if (i < 63) Serial.print(',');
+  }
+  Serial.println();
+}
+
+// print current threshold values as CSV
+void printCurrentThreshold() {
+#if USE_GLOBAL_THRESHOLD
+  // Global Threshold - print one value
+   Serial.println(THRESHOLD);
+#else
+  // Individual Thresholds - print 64 values
+  for (int i = 0; i < 64; ++i) {
+    Serial.print(THRESHOLD[i]);
+    if (i < 63) Serial.print(',');
+  }
+  Serial.println();
+#endif
+}
+
 void setup() {
   delay(3000);
   Serial.begin(9600);
 }
 
 void loop() {
-  currentBinBoard = board.getBinaryBoard(THRESHOLD);
-  if (currentBinBoard != lastBinBoard) {
-    writeBinaryBoard(currentBinBoard);
-    lastBinBoard = currentBinBoard;
+  // Serial Monitor arguements
+  if (Serial.available()) {
+    int c = Serial.read();
+    // if host sends '?', reply with one CSV line of raw ADC values
+    if (c == '?') {
+      printRawSnapshotCSV();
+    }
+
+    // if host sends '!', reply with current threshold values
+    if (c == '!') {
+      printCurrentThreshold();
+    }
+
+    // Toggle quiet mode (Used to silence bitboard output)
+    if (c == 'q' && quiet == false) {
+      quiet = true;
+      Serial.println("Quiet Mode Activated!");
+    }
+    else if (c == 'q' && quiet == true) {
+      quiet = false;
+      Serial.println("Exited Quiet Mode!");
+    }
+
+    // Calibration Mode for editing THRESHOLD
+    if (c == 'c') {
+      calibrating = true;
+      Serial.println("Calibration Mode Activated!");
+    }
+
+    while (calibrating) {
+      if (Serial.available()){
+        // read a whole line the user pasted
+        String line = Serial.readStringUntil('\n');
+        line.trim();
+        if (line.length() == 0) continue;
+
+#if USE_GLOBAL_THRESHOLD        
+        // Global Threshold Calibration
+        long newThreshold = line.toInt();
+        THRESHOLD = (unsigned short)newThreshold;
+#else
+        // Per-Square Calibration
+        char buf[1024];
+        line.toCharArray(buf, 1024);
+        char* tok = strtok(buf, ",");
+
+        int i = 0;
+        while (tok && i < 64) {
+          THRESHOLD[i++] = (unsigned short)atoi(tok);
+          tok = strtok(nullptr, ",");
+        }
+#endif
+        calibrating = false;
+        // eat non-numeric to avoid getting stuck
+        while (Serial.available()) Serial.read();
+      }
+    }
+  }
+
+  // Bitboard logic for normal use
+  if (!quiet && !calibrating) {
+    currentBinBoard = board.getBinaryBoard(THRESHOLD);
+    if (currentBinBoard != lastBinBoard) {
+      writeBinaryBoard(currentBinBoard);
+      lastBinBoard = currentBinBoard;
+    }
   }
 }