main: Use both RFID readers

As our RFID tags cannot co-exist on the same reader as originally plan,
handle another reader on SPI1.
Checking tags is not time sensitive and can be made in successive loops, which
minimizes the changes needed from the original code.

README.md

@@ -42,6 +42,7 @@ se synchroniser avec le firmware et potentiellement le mettre à jour.
  - [ ] Contrôle des modules
    - [x] RFID (base)
    - [x] RFID (avancé, écriture des tags)
+   - [x] RFID (deux lecteurs)
    - [x] LCD (base)
    - [x] LCD (animations)
    - [ ] LCD (UI)
@@ -204,6 +205,7 @@ est un personnage (1) ou une année (0) sur le bit 6 et si la figurine a été p
 (0) ou retirée (1) sur le bit 7.  
 Ainsi, si on interprète l'octet comme un nombre signé, si le nombre est négatif
 on sait que la figurine a été retirée.  
+**_Dû à un détail d'implémentation, l'identifiant 127 est invalide et réservé._**
 
 #### Schéma
 ```

include/RFID.h

@@ -32,6 +32,8 @@ struct uidNode {
 class RFID {
 public:
 	static constexpr int maxTags = 2;
+	/* Error value returned when checking for new or gone tags. */
+	static constexpr int8_t checkFail = -1;
 
 	/***
 	 * Use the main SPI port and NFC chip select by default, but allow choosing
@@ -48,7 +50,8 @@ public:
 	 * at a time, another call would be needed to get eventual concurrent events.
 	 * This updates the respective lists and returns the ID with the direction
 	 * of the change.
-	 * @return 0 if no change, ID if new tag detected, ID & sign bit if the tag left.
+	 * @return ID if new tag detected, ID & sign bit if the tag left
+	 * @return RFID::checkFail if no change or error.
 	 */
 	int8_t checkTags();
 

src/Com.cpp

@@ -20,6 +20,7 @@ namespace Com {
 		usb_rawhid_send(buffer, 0);
 #else
 		Serial.write((const char*)buffer);
+		Serial.write('\n');
 #endif
 		/* Clear the buffer. */
 		memset(buffer, 0, sizeof(buffer));

src/RFID.cpp

@@ -52,19 +52,19 @@ int8_t RFID::checkTags() {
 	if ( currentActiveTags >= maxTags ||
 		 !mfrc.PICC_IsNewCardPresent() ||
 		 !mfrc.PICC_ReadCardSerial()) {
-		return 0;
+		return checkFail;
 	}
 
 	// Assume we have a new tag.
 	uidNode* newTag = addActiveTag(mfrc.uid);
 	// Tag ID is put in a specific block, which can be read after from comData.
 	if ( !newTag ) {
-		return 0;
+		return checkFail;
 	}
 	// If the read fails, we cannot use this tag anyway so remove it from the list.
 	if (!readBlock(newTag->uid, tagIdBlock) ) {
 		removeActiveTag(newTag, nullptr);
-		return 0;
+		return checkFail;
 	}
 	// Don't check the ID, otherwise we cannot program the tag.
 	newTag->tag_ID = comData[0];

src/main.cpp

@@ -16,11 +16,13 @@ __attribute__((noreturn)) int main() {
 	pinMode(pin_Audio_AMP_GAIN_EN, OUTPUT);
 
 	pinMode(pin_NFC1_RST, OUTPUT);
+	pinMode(pin_NFC2_RST, OUTPUT);
 	pinMode(pin_LCD_RST, OUTPUT);
 
 	/* Preemptively disable what we can before the regulator is ON. */
 	digitalWrite(pin_Audio_Amp_enable, LOW);
 	digitalWrite(pin_NFC1_RST, LOW);
+	digitalWrite(pin_NFC2_RST, LOW);
 	digitalWrite(pin_LCD_RST, LOW);
 
 	pinMode(pin_BAT_SNS, INPUT);
@@ -45,6 +47,11 @@ __attribute__((noreturn)) int main() {
 	digitalWrite(pin_NFC1_RST, HIGH);
 	rfid.init();
 
+	SPI1.setMISO(pin_SPI1_CIPO);
+	RFID rfid2(pin_NFC2_CS, SPI1);
+	digitalWrite(pin_NFC2_RST, HIGH);
+	rfid2.init();
+
 	if (!SD.begin(BUILTIN_SDCARD))
 		Com::sendComment("Could not use the SD Card.");
 
@@ -66,8 +73,15 @@ __attribute__((noreturn)) int main() {
 		lcd.checkAndDisplay();
 		speaker.checkPlayingAndDisable();
 
+		/*
+		 * In the unlikely case where two changes happen in the same cycle, we
+		 * can check the second RFID reader on the next one.
+		 */
 		tagEvent = rfid.checkTags();
-		if (tagEvent) {
+		if (tagEvent == RFID::checkFail) {
+			tagEvent = rfid2.checkTags();
+		}
+		if (tagEvent != RFID::checkFail) {
 			Com::sendFigUpdate(tagEvent);
 			/* Currently, we only play effects when placing a new figurine. */
 			if (!isIdGone(tagEvent)) {
@@ -80,9 +94,11 @@ __attribute__((noreturn)) int main() {
 		Com::ReceivedMessage message = Com::receiveMessage();
 		if (message == Com::TAG_INFO_REQUEST) {
 			uint8_t tagCount = rfid.gatherTagInfo(Com::getTagRecords());
+			tagCount += rfid2.gatherTagInfo(Com::getTagRecords() + tagCount);
 			Com::sendTagInfo(tagCount);
 		} else if (message == Com::TAG_PROGRAMMING) {
-			if (!rfid.programTag(Com::getTagRecords())) {
+			if (!rfid.programTag(Com::getTagRecords()) &&
+				!rfid2.programTag(Com::getTagRecords())) {
 				Com::sendComment("Tag programming failed.");
 			}
 		}