[examples] Add PinScan example

examples/PinScan/src/digital.cpp

@@ -0,0 +1,200 @@
+/* Copyright (c) Kuba Szczodrzyński 2022-07-31. */
+
+#include "main.h"
+
+#define PULL  0
+#define WRITE 1
+
+static bool pins[NUM_DIGITAL_PINS] = {};
+static bool used[NUM_DIGITAL_PINS] = {};
+static bool active				   = false;
+static int pin					   = -1;
+
+static unsigned long last = 0;
+static bool outputMode	  = PULL;
+
+static void printPin(bool state) {
+	if (ansi) {
+		stream->print(state ? (ANSI_RED "HI" ANSI_RESET) : (ANSI_BLUE "LO" ANSI_RESET));
+	} else {
+		stream->print(state ? "HI" : "LO");
+	}
+}
+
+static void printState() {
+	printAnsi(ANSI_TWO_LINES);
+	printAnsi(ANSI_ERASE_LINE);
+	for (pin_size_t i = 0; i < NUM_DIGITAL_PINS; i++) {
+		if (i < 10)
+			stream->write(' ');
+		stream->write('D');
+		stream->print(i);
+		stream->write(' ');
+	}
+	stream->println();
+	printAnsi(ANSI_ERASE_LINE);
+	for (pin_size_t i = 0; i < NUM_DIGITAL_PINS; i++) {
+		stream->write(' ');
+		if (used[i]) {
+			printPin(pins[i]);
+		} else {
+			stream->print("--");
+		}
+		stream->write(' ');
+	}
+	stream->println();
+}
+
+static void irqHandler(void *ptr) {
+	bool *pin	 = (bool *)ptr;
+	pin_size_t i = pin - pins;
+	pins[i]		 = digitalRead(i);
+	// change interrupt level according to current state
+	PinStatus status = pins[i] ? FALLING : RISING;
+	attachInterruptParam(i, irqHandler, status, ptr);
+	printState();
+}
+
+static void digitalAllIrq() {
+	for (pin_size_t i = 0; i < NUM_DIGITAL_PINS; i++) {
+		if (pinSkip[0] == i || pinSkip[1] == i) {
+			used[i] = false;
+			continue;
+		}
+		pinMode(i, INPUT);
+		// choose interrupt level according to current state
+		PinStatus status = digitalRead(i) ? FALLING : RISING;
+		attachInterruptParam(i, irqHandler, status, pins + i);
+		used[i] = true;
+		pins[i] = digitalRead(i);
+	}
+	active = true;
+}
+
+static void digitalOut(pin_size_t pin, PinStatus state) {
+	if (outputMode == PULL) {
+		pinMode(pin, state ? INPUT_PULLUP : INPUT_PULLDOWN);
+	} else {
+		pinMode(pin, OUTPUT);
+		digitalWrite(pin, state);
+	}
+	pins[pin] = state;
+}
+
+static int digitalAllLow() {
+	int first = -1;
+	for (pin_size_t i = 0; i < NUM_DIGITAL_PINS; i++) {
+		if (pinSkip[0] == i || pinSkip[1] == i) {
+			used[i] = false;
+			continue;
+		}
+		if (first == -1)
+			first = i;
+		digitalOut(i, LOW);
+		used[i] = true;
+	}
+	active = true;
+	return first;
+}
+
+void digitalDetach() {
+	outputMode = PULL;
+	if (!active)
+		return;
+	for (pin_size_t i = 0; i < NUM_DIGITAL_PINS; i++) {
+		if (pinSkip[0] == i || pinSkip[1] == i) {
+			continue;
+		}
+		if (used[i])
+			detachInterrupt(i);
+		used[i] = false;
+		pinMode(i, INPUT_PULLDOWN);
+	}
+	active = false;
+	pin	   = -1;
+}
+
+void runDigital() {
+	if (mode[1] == '\0')
+		return;
+	switch (mode[1]) {
+		case '?':
+			printHelp('d');
+			pin = -1;
+			break;
+
+		case 'p':
+			outputMode = PULL;
+			stream->println("Will pull outputs UP/DOWN");
+			mode[1]		  = '?';
+			ansiSkipErase = true;
+			return;
+		case 'w':
+			outputMode = WRITE;
+			stream->println("Will write LOW/HIGH to outputs");
+			mode[1]		  = '?';
+			ansiSkipErase = true;
+			return;
+
+		case 'r':
+			if (!active) {
+				digitalAllIrq();
+				if (ansi)
+					printHelp('d');
+				printAnsi("\n\n"); // reserve two lines for readouts
+				printState();
+			}
+			return;
+
+		case 'o':
+			if (pin == -1) {
+				pin = inputPin();
+				pinMode(pin, INPUT);
+			}
+			printAnsi(ANSI_LINE_START);
+			stream->print("Pin D");
+			stream->print(pin);
+			stream->print(" state: ");
+			printPin(digitalRead(pin));
+			if (!ansi)
+				stream->println();
+			return;
+
+		case 's':
+			if (pin == -1) {
+				// choose the first pin
+				pin = digitalAllLow();
+				if (ansi)
+					printHelp('d');
+				printAnsi("\n\n"); // reserve two lines for readouts
+				printState();
+			}
+			if (mode[2] == 'n') {
+				// go to next pin; leave the current as LOW
+				digitalOut(pin, LOW);
+				do {
+					if (++pin >= NUM_DIGITAL_PINS)
+						pin = 0;
+				} while (used[pin] == false);
+				printState();
+			}
+			mode[2] = '\0';
+			// toggle the pin every 500ms
+			if (millis() - last < 500)
+				return;
+			last = millis();
+			digitalOut(pin, (PinStatus)!pins[pin]);
+			printState();
+			return;
+
+		case 'h':
+		case 'l':
+			pin = inputPin();
+			digitalOut(pin, mode[1] == 'h' ? HIGH : LOW);
+			stream->println("OK");
+			mode[1]		  = '?';
+			ansiSkipErase = true;
+			return;
+	}
+	mode[1] = '\0';
+}