Add esp8266 hardware uart support with an example!

Author: arduino12

examples/esp8266_hardware_uart/esp8266_hardware_uart.ino

@@ -0,0 +1,60 @@
+/*
+ * A simple example to interface with rdm6300 rfid reader using esp8266.
+ * We use hardware uart "Serial" instead of the default software uart driver.
+ *
+ * Note:
+ *     The esp8266 let us use 1.5 uarts:
+ *     Serial=uart0=rx+tx, Serial1=uart1=tx only (rx pin is used as flash io).
+ *     Here we sawp the uart pins so uart0_rx goes to the rdm6300_tx,
+ *     and uart1_tx goes to what used to be uart0_tx-
+ *     so debug message goes from Serial1.print(...) to the pc debug terminal.
+ *     https://github.com/esp8266/Arduino/blob/master/doc/reference.rst#serial
+ *
+ * Connections:
+ *     | esp8266 | nodemcu | rdm6300 | notes                               |
+ *     |---------+---------+---------|-------------------------------------|
+ *     | GPIO-01 | TX      |         | This is TXD0, connect it to GPIO-02 |
+ *     | GPIO-02 | D4      |         | This is TXD1, connect it to GPIO-01 |
+ *     | GPIO-03 | RX      |         | Leave it unconnected for flashing   |
+ *     | GPIO-13 | D7      | TX      | Via voltage divide / level shifter  |
+ *     |         | VU (5V) | VCC     |                                     |
+ *     | GND     | GND     | GND     |                                     |
+ *
+ *     * GPIO-01 to GPIO-02 is for debug terminal output.
+ *     * You must divide the TX out of the rdm6300 to the 3.3V levels,
+ *       I used the following resistor divider:
+ *       GND--<2K resistor>--GPIO-13=D7--<1K resistor>--TX(rdm6300).
+ *
+ * Arad Eizen (https://github.com/arduino12) 08/05/19.
+ */
+
+#include <rdm6300.h>
+
+#define RDM6300_RX_PIN 13 // can be only 13 - on esp8266 force hardware uart!
+#define READ_LED_PIN 16
+
+Rdm6300 rdm6300;
+
+void setup()
+{
+	/* Serial1 is the debug! remember to bridge GPIO-01 to GPIO-02 */
+	Serial1.begin(115200);
+
+	pinMode(READ_LED_PIN, OUTPUT);
+	digitalWrite(READ_LED_PIN, LOW);
+
+	rdm6300.begin(RDM6300_RX_PIN);
+
+	Serial1.println("\nPlace RFID tag near the rdm6300...");
+}
+
+void loop()
+{
+	/* if non-zero tag_id, update() returns true- a new tag is near! */
+	if (rdm6300.update())
+		Serial1.println(rdm6300.get_tag_id(), HEX);
+
+	digitalWrite(READ_LED_PIN, rdm6300.is_tag_near());
+
+	delay(10);
+}

keywords.txt

@@ -12,6 +12,7 @@ Rdm6300	KEYWORD1
 # Methods and Functions (KEYWORD2)
 #######################################
 begin		KEYWORD2
+end			KEYWORD2
 update		KEYWORD2
 get_tag_id	KEYWORD2
 is_tag_near	KEYWORD2

library.json

@@ -1,6 +1,6 @@
 {
   "name": "rdm6300",
-  "version": "1.0.2",
+  "version": "1.1.0",
   "keywords": "rdm6300, rfid",
   "description": "A simple library to interface with rdm6300 rfid reader.",
   "repository":

library.properties

@@ -1,5 +1,5 @@
 name=Rdm6300
-version=1.0.2
+version=1.1.0
 author=Arad Eizen
 maintainer=Arad Eizen <https://github.com/arduino12>
 sentence=A simple library to interface with rdm6300 rfid reader.

src/rdm6300.cpp

@@ -10,14 +10,40 @@
 void Rdm6300::begin(int rx_pin, uint8_t uart_nr)
 {
 	/* init serial port to rdm6300 baud, without TX, and 20ms read timeout */
-#ifdef ARDUINO_ARCH_ESP32
-	_serial = new HardwareSerial(uart_nr);
-	_serial->begin(RDM6300_BAUDRATE, SERIAL_8N1, rx_pin, -1);
-#else
-	_serial = new SoftwareSerial(rx_pin, -1);
-	_serial->begin(RDM6300_BAUDRATE);
+	end();
+#if defined(ARDUINO_ARCH_ESP32)
+	_stream = _hardware_serial = new HardwareSerial(uart_nr);
+	_hardware_serial->begin(RDM6300_BAUDRATE, SERIAL_8N1, rx_pin, -1);
+#elif defined(ARDUINO_ARCH_ESP8266)
+	if (rx_pin == 13) {
+		_stream = _hardware_serial = &Serial;
+		_hardware_serial->begin(RDM6300_BAUDRATE, SERIAL_8N1, SERIAL_RX_ONLY);
+		if (uart_nr)
+			_hardware_serial->swap();
+	}
+#endif
+#ifdef RDM6300_SOFTWARE_SERIAL
+	if (!_hardware_serial) {
+		_stream = _software_serial = new SoftwareSerial(rx_pin, -1);
+		_software_serial->begin(RDM6300_BAUDRATE);
+	}
+#endif
+	if (!_stream)
+		return;
+	_stream->setTimeout(RDM6300_READ_TIMEOUT);
+}
+
+void Rdm6300::end()
+{
+	_stream = NULL;
+#ifdef RDM6300_HARDWARE_SERIAL
+	if (_hardware_serial)
+		_hardware_serial->end();
+#endif
+#ifdef RDM6300_SOFTWARE_SERIAL
+	if (_software_serial)
+		_software_serial->end();
 #endif
-	_serial->setTimeout(20);
 }
 
 bool Rdm6300::update(void)
@@ -26,15 +52,18 @@ bool Rdm6300::update(void)
 	uint32_t tag_id;
 	uint8_t checksum;
 
-	if (!_serial->available())
+	if (!_stream)
+		return false;
+
+	if (!_stream->available())
 		return false;
 
 	/* if a packet doesn't begin with the right byte, remove that byte */
-	if (_serial->peek() != RDM6300_PACKET_BEGIN && _serial->read())
+	if (_stream->peek() != RDM6300_PACKET_BEGIN && _stream->read())
 		return false;
 
 	/* if read a packet with the wrong size, drop it */
-	if (RDM6300_PACKET_SIZE != _serial->readBytes(buff, RDM6300_PACKET_SIZE))
+	if (RDM6300_PACKET_SIZE != _stream->readBytes(buff, RDM6300_PACKET_SIZE))
 		return false;
 
 	/* if a packet doesn't end with the right byte, drop it */

src/rdm6300.h

@@ -1,36 +1,53 @@
 /*
  * A simple library to interface with rdm6300 rfid reader.
- * Arad Eizen (https://github.com/arduino12) 23/09/18.
+ *
+ * Arad Eizen (https://github.com/arduino12) 23/09/18, 08/05/19.
  */
 
 #ifndef _RDM6300_h_
 #define _RDM6300_h_
 
-#ifdef ARDUINO_ARCH_ESP32
+#if defined(ARDUINO_ARCH_ESP32) || defined(ARDUINO_ARCH_ESP8266)
+	#define RDM6300_HARDWARE_SERIAL
+#endif
+
+#if !defined(ARDUINO_ARCH_ESP32)
+	#define RDM6300_SOFTWARE_SERIAL
+#endif
+
+#ifdef RDM6300_HARDWARE_SERIAL
 	#include <HardwareSerial.h>
-#else
+#endif
+#ifdef RDM6300_SOFTWARE_SERIAL
 	#include <SoftwareSerial.h>
 #endif
 
+#include <Stream.h>
+
 #define RDM6300_BAUDRATE		9600
 #define RDM6300_PACKET_SIZE		14
 #define RDM6300_PACKET_BEGIN	0x02
 #define RDM6300_PACKET_END		0x03
 #define RDM6300_NEXT_READ_MS	220
+#define RDM6300_READ_TIMEOUT	20
 
 class Rdm6300
 {
 	public:
 		void begin(int rxPin, uint8_t uart_nr=1);
+		void end(void);
 		bool update(void);
 		uint32_t get_tag_id(void);
 		bool is_tag_near(void);
 	private:
-#ifdef ARDUINO_ARCH_ESP32
-		HardwareSerial * _serial;
-#else
-		SoftwareSerial * _serial;
+		void _begin(void);
+#ifdef RDM6300_HARDWARE_SERIAL
+		HardwareSerial *_hardware_serial = NULL;
+#endif
+#ifdef RDM6300_SOFTWARE_SERIAL
+		SoftwareSerial *_software_serial = NULL;
 #endif
+		Stream *_stream = NULL;
 		uint32_t _tag_id = 0;
 		uint32_t _last_tag_id = 0;
 		uint32_t _next_read_ms = 0;