HardwareSerial::write(const char*, ...) API compatibility to AVR, ESP…

…8266, et al (espressif#3585) * API compatibility to AVR, ESP8266, et al * Add non-blocking HardwareSerial::read(buffer, size) extension (ESP8266 portability) * Refactor for fewer indirect calls.

cores/esp32/HardwareSerial.cpp

@@ -131,6 +131,24 @@ int HardwareSerial::read(void)
  return -1;
 }
 
+// read characters into buffer
+// terminates if size characters have been read, or no further are pending
+// returns the number of characters placed in the buffer
+// the buffer is NOT null terminated.
+size_t HardwareSerial::read(uint8_t *buffer, size_t size)
+{
+ size_t avail = available();
+ if (size < avail) {
+ avail = size;
+ }
+ size_t count = 0;
+ while(count < avail) {
+ *buffer++ = uartRead(_uart);
+ count++;
+ }
+ return count;
+}
+
 void HardwareSerial::flush(void)
 {
  uartFlush(_uart);

cores/esp32/HardwareSerial.h

@@ -62,11 +62,19 @@ class HardwareSerial: public Stream
  int availableForWrite(void);
  int peek(void);
  int read(void);
+ size_t read(uint8_t *buffer, size_t size);
+ inline size_t read(char * buffer, size_t size)
+ {
+ return read((uint8_t*) buffer, size);
+ }
  void flush(void);
  void flush( bool txOnly);
  size_t write(uint8_t);
  size_t write(const uint8_t *buffer, size_t size);
-
+ inline size_t write(const char * buffer, size_t size)
+ {
+ return write((uint8_t*) buffer, size);
+ }
  inline size_t write(const char * s)
  {
  return write((uint8_t*) s, strlen(s));