From 0607d36734d52d67be1b88764bf446fac7eb62f3 Mon Sep 17 00:00:00 2001
From: "Dirk O. Kaar" <19971886+dok-net@users.noreply.github.com>
Date: Mon, 20 Jan 2020 14:54:50 +0100
Subject: [PATCH] HardwareSerial::write(const char*, ...) API compatibility to
 AVR, ESP8266, et al (#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 | 18 ++++++++++++++++++
 cores/esp32/HardwareSerial.h   | 10 +++++++++-
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/cores/esp32/HardwareSerial.cpp b/cores/esp32/HardwareSerial.cpp
index 860c2c0f..be80ca27 100644
--- a/cores/esp32/HardwareSerial.cpp
+++ b/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);
diff --git a/cores/esp32/HardwareSerial.h b/cores/esp32/HardwareSerial.h
index 7d9f26d2..82047674 100644
--- a/cores/esp32/HardwareSerial.h
+++ b/cores/esp32/HardwareSerial.h
@@ -62,11 +62,19 @@ public:
     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));