From 8b4eb9e938c7f25153b5a2a03636e4363d404c93 Mon Sep 17 00:00:00 2001
From: Gregor Riepl <onitake@gmail.com>
Date: Thu, 22 Apr 2021 00:36:43 +0200
Subject: [PATCH] Rewrote VFD pin access functions

---
 display/firmware/display.c | 109 ++++++++++++++++++++++++-------------
 1 file changed, 71 insertions(+), 38 deletions(-)

diff --git a/display/firmware/display.c b/display/firmware/display.c
index bbcd942..3b643cf 100644
--- a/display/firmware/display.c
+++ b/display/firmware/display.c
@@ -24,6 +24,60 @@ void display_init() {
 	display_wait_ready();
 }
 
+static void display_set_rs(bool on) {
+	if (on) {
+		PORTC |= _BV(PC5);
+	} else {
+		PORTC &= ~_BV(PC5);
+	}
+}
+
+static void display_set_rw(bool on) {
+	if (on) {
+		PORTC |= _BV(PC6);
+	} else {
+		PORTC &= ~_BV(PC6);
+	}
+}
+
+static void display_set_e(bool on) {
+	if (on) {
+		PORTC |= _BV(PC7);
+	} else {
+		PORTC &= ~_BV(PC7);
+	}
+}
+
+static void display_set_data(uint8_t data) {
+	uint8_t datab = PORTB & ~(_BV(PB0) | _BV(PB1) | _BV(PB7));
+	uint8_t datad = PORTD & ~(_BV(PD0) | _BV(PD1) | _BV(PD5) | _BV(PD6) | _BV(PD7));
+	datab |= (data & _BV(2)) ? _BV(PB0) : 0;
+	datab |= (data & _BV(3)) ? _BV(PB1) : 0;
+	datab |= (data & _BV(4)) ? _BV(PB7) : 0;
+	datad |= (data & _BV(0)) ? _BV(PD0) : 0;
+	datad |= (data & _BV(1)) ? _BV(PD1) : 0;
+	datad |= (data & _BV(5)) ? _BV(PD5) : 0;
+	datad |= (data & _BV(6)) ? _BV(PD6) : 0;
+	datad |= (data & _BV(7)) ? _BV(PD7) : 0;
+	PORTB = datab;
+	PORTD = datad;
+}
+
+static uint8_t display_get_data() {
+	uint8_t datab = PINB;
+	uint8_t datad = PIND;
+	uint8_t data = 0;
+	data |= (datad & _BV(PD0)) ? _BV(0) : 0;
+	data |= (datad & _BV(PD1)) ? _BV(1) : 0;
+	data |= (datad & _BV(PD5)) ? _BV(5) : 0;
+	data |= (datad & _BV(PD6)) ? _BV(6) : 0;
+	data |= (datad & _BV(PD7)) ? _BV(7) : 0;
+	data |= (datab & _BV(PB0)) ? _BV(2) : 0;
+	data |= (datab & _BV(PB1)) ? _BV(3) : 0;
+	data |= (datab & _BV(PB7)) ? _BV(4) : 0;
+	return data;
+}
+
 uint8_t display_read_ir() {
 	// switch PD to input
 	DDRB &= ~(_BV(PB0) | _BV(PB1) | _BV(PB7));
@@ -93,61 +147,40 @@ uint8_t display_read_dr() {
 }
 
 void display_write_ir(uint8_t data) {
-	// reassemble data
-	uint8_t datab = 0;
-	uint8_t datad = 0;
-	datad |= (data & _BV(0)) ? _BV(PD0) : 0;
-	datad |= (data & _BV(1)) ? _BV(PD1) : 0;
-	datad |= (data & _BV(5)) ? _BV(PD5) : 0;
-	datad |= (data & _BV(6)) ? _BV(PD6) : 0;
-	datad |= (data & _BV(7)) ? _BV(PD7) : 0;
-	datab |= (data & _BV(2)) ? _BV(PB0) : 0;
-	datab |= (data & _BV(3)) ? _BV(PB1) : 0;
-	datab |= (data & _BV(4)) ? _BV(PB7) : 0;
-	// E=0 (enable/clock) RS=0 (IR) RW=0 (write)
-	PORTC &= ~(_BV(PC5) | _BV(PC6) | _BV(PC7));
+	// RS=0 (IR) RW=0 (write)
+	display_set_rs(false);
+	display_set_rw(false);
 	_delay_us(0.23);
 	// E=1 (enable/clock)
-	PORTC |= _BV(PC7);
+	display_set_e(true);
 	// send data
-	PORTB = datab;
-	PORTD = datad;
+	display_set_data(data);
 	_delay_us(0.23);
 	// E=0 (enable/clock)
-	PORTC &= ~_BV(PC7);
+	display_set_e(false);
 	_delay_us(0.01);
 	// reset to idle
-	PORTC = _BV(PC6) | _BV(PC7);
-	PORTD = 0x00;
+	display_set_rs(true);
+	display_set_rw(true);
+	display_set_data(0);
 }
 
 void display_write_dr(uint8_t data) {
-	// reassemble data
-	uint8_t datab = 0;
-	uint8_t datad = 0;
-	datad |= (data & _BV(0)) ? _BV(PD0) : 0;
-	datad |= (data & _BV(1)) ? _BV(PD1) : 0;
-	datad |= (data & _BV(5)) ? _BV(PD5) : 0;
-	datad |= (data & _BV(6)) ? _BV(PD6) : 0;
-	datad |= (data & _BV(7)) ? _BV(PD7) : 0;
-	datab |= (data & _BV(2)) ? _BV(PB0) : 0;
-	datab |= (data & _BV(3)) ? _BV(PB1) : 0;
-	datab |= (data & _BV(4)) ? _BV(PB7) : 0;
-	// E=0 (enable/clock) RS=1 (IR) RW=0 (write)
-	PORTC = (PORTC & ~(_BV(PC6) | _BV(PC7))) | _BV(PC5);
+	// RS=1 (DR) RW=0 (write)
+	display_set_rs(true);
+	display_set_rw(false);
 	_delay_us(0.23);
 	// E=1 (enable/clock)
-	PORTC |= _BV(PC7);
+	display_set_e(true);
 	// send data
-	PORTB = datab;
-	PORTD = datad;
+	display_set_data(data);
 	_delay_us(0.23);
 	// E=0 (enable/clock)
-	PORTC &= ~_BV(PC7);
+	display_set_e(false);
 	_delay_us(0.01);
 	// reset to idle
-	PORTC = _BV(PC6) | _BV(PC7);
-	PORTD = 0x00;
+	display_set_rw(true);
+	display_set_data(0);
 }