avr-something

commit 0ae92ac6f34c8bbc1d059809f4a144c5d3445803
parent 16cdc9385b1c3ff1516b54186ba29d70d38c2dec
Author: Henry Wilson <m3henry@googlemail.com>
Date:   Tue, 13 Feb 2018 20:29:24 +0000

Put load from flash memory in a class

Diffstat:
M
lcd.cpp
 | 
16
++++++----------
M
makefile
 | 
2
+-
M
utils.h
 | 
45
+++++++++++++++++++++++++++++++++------------

3 files changed, 40 insertions(+), 23 deletions(-)
diff --git a/lcd.cpp b/lcd.cpp
@@ -161,13 +161,12 @@ struct
 		
 		auto g = drawSequence();
 		
-		uint8_t const* bytePtr = fonts::mash[c - ' '];
+		auto bytePtr = flashPtr(fonts::mash[c - ' ']);
 		
 		uint8_t x = 8;
 		do
 		{
-			//auto byte = pgm_read_byte(bytePtr++);
-			auto byte = loadPROGMEM(bytePtr);
+			auto byte = bytePtr.load_post_inc();
 			send(byte & bit(7) ? foreground : background);
 			send(byte & bit(6) ? foreground : background);
 			send(byte & bit(5) ? foreground : background);
@@ -182,15 +181,12 @@ struct
 	void newline()
 	{
 		y += 8;
+		x = 0;
 	}
 	void advance(uint8_t count = 1)
 	{
-		if (x >= 320 - 8)
-		{
-			newline();
-			x -= 320;
-		}
-		x += count * 8;
+		if (x >= 320 - 8) newline();
+		else x += count * 8;
 	}
 	void puts(char const* str)
 	{
@@ -205,7 +201,7 @@ struct
 
 void testFont()
 {
-	lout.puts("Hello, World! It is a very nice day today, what are you up to today?");
+	lout.puts("Hello, World!\nIt is a very nice day today, what are you up to today?");
 }
 
 }
diff --git a/makefile b/makefile
@@ -25,7 +25,7 @@ program.elf: $(OBJECTS)
 
 # The install target
 install: program.hex
-	@ avrdude -c usbasp -p m644p -U $<
+	@ avrdude -c usbasp -p m644p -D -U $<
 
 # Clean up everything that we generate
 clean:
diff --git a/utils.h b/utils.h
@@ -36,17 +36,38 @@ inline constexpr uint8_t mix(const uint8_t a, const uint8_t b, const uint8_t mas
 	return (a & ~mask) | (b & mask);
 }
 
+struct flashPtr
+{
+	inline flashPtr(uint8_t const* const p) : ptr(p) {}
+	inline uint8_t load() const
+	{
+		uint8_t result;
+		asm volatile
+		(
+			"lpm %0, Z"
+
+			: "=r" (result)
+			: "z" (ptr)
+		);
+		return result;
+	}
+	inline uint8_t load_post_inc()
+	{
+		uint8_t result;
+		asm volatile
+		(
+			"lpm %0, Z+"
+
+			: "=r" (result), "=z" (ptr)
+			: "1" (ptr)
+		);
+		return result;
+	}
+
+	static_assert(sizeof(uint16_t) == sizeof(uint8_t const *), "Flash ptr should be a word");
+
+private:
+	uint8_t const* ptr;
+};
 
 
-inline uint8_t loadPROGMEM(uint8_t const* &addr)
-{
-	uint8_t result;
-	asm volatile
-	(
-		"lpm %0, Z+"
-		
-		: "=r" (result), "=z" (addr)
-		: "1" (addr)
-	);
-	return result;            
-}