From 4e43ab11e85b73ebbf5efbd2d43f89e68f30c36e Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Mon, 15 Nov 2010 21:07:41 +0000
Subject: [PATCH] Make LCD output selectable at runtime through an extra I/O
 pin

---
 firmware/s88w-r.c | 62 ++++++++++++++++++++++++++++++++++-------------
 1 file changed, 45 insertions(+), 17 deletions(-)

diff --git a/firmware/s88w-r.c b/firmware/s88w-r.c
index 730ac10..d2a2109 100644
--- a/firmware/s88w-r.c
+++ b/firmware/s88w-r.c
@@ -34,6 +34,8 @@ D5 - S88 RESET
 #define LOAD     PIND4
 #define RESET    PIND5
 
+#define LCD_DISABLE PINB4
+
 #define BIT(n)   (1<<(n))
 
 void receive(uint8_t);
@@ -44,6 +46,7 @@ volatile uint8_t rx_buf[7];
 volatile uint8_t rx_fill = 0xFF;
 volatile uint8_t input[128] = { 0 };
 volatile uint8_t latch[128] = { 0 };
+volatile uint8_t lcd_enabled = 0;
 uint8_t log_row = 0;
 uint8_t log_col = 0;
 
@@ -65,14 +68,11 @@ int main()
 
 	sei();
 
-	lcd_clear();
-	for(i=0; i<20; ++i)
-		lcd_write('0');
-
 	while(1)
 	{
-		uint8_t d_pins;
+		uint8_t b_pins, d_pins;
 
+		b_pins = PINB;
 		d_pins = PIND;
 
 		if(d_pins&BIT(CLOCK))
@@ -113,6 +113,28 @@ int main()
 			for(i=0; i<128; ++i)
 				latch[i] = input[i];
 		}
+
+		if(b_pins&BIT(LCD_DISABLE))
+		{
+			if(lcd_enabled)
+			{
+				lcd_enabled = 0;
+
+				lcd_clear();
+			}
+		}
+		else if(!lcd_enabled)
+		{
+			lcd_enabled = 1;
+			log_row = 0;
+			log_col = 0;
+
+			lcd_clear();
+			for(i=0; i<20; ++i)
+				lcd_write(hexdigit(input[9-i/2]>>(4-i%2*4)));
+			lcd_gotoxy(0, 1);
+			lcd_write(255);
+		}
 	}
 }
 
@@ -145,9 +167,12 @@ void receive(uint8_t c)
 					latch[j/2] = input[j/2];
 				}
 
-				lcd_gotoxy(19-offset-nibbles, 0);
-				for(i=0; i<=nibbles; ++i)
-					lcd_write(rx_buf[3+i]);
+				if(lcd_enabled)
+				{
+					lcd_gotoxy(19-offset-nibbles, 0);
+					for(i=0; i<=nibbles; ++i)
+						lcd_write(rx_buf[3+i]);
+				}
 			}
 		}
 		rx_fill = 0xFF;
@@ -160,18 +185,21 @@ void receive(uint8_t c)
 			rx_fill = 0xFF;
 	}
 
-	lcd_gotoxy(log_col, 1+log_row);
-	lcd_write(c);
-	++log_col;
-	if(log_col>=20)
+	if(lcd_enabled)
 	{
-		log_col = 0;
-		++log_row;
-		if(log_row>=3)
-			log_row = 0;
 		lcd_gotoxy(log_col, 1+log_row);
+		lcd_write(c);
+		++log_col;
+		if(log_col>=20)
+		{
+			log_col = 0;
+			++log_row;
+			if(log_row>=3)
+				log_row = 0;
+			lcd_gotoxy(log_col, 1+log_row);
+		}
+		lcd_write(255);
 	}
-	lcd_write(255);
 }
 
 SERIAL_SET_CALLBACK(receive)
-- 
2.43.0