diff --git a/display/firmware/main.c b/display/firmware/main.c
index b35e891..f36acc6 100644
--- a/display/firmware/main.c
+++ b/display/firmware/main.c
@@ -98,6 +98,10 @@ static void init() {
 
 	// initialize VFD
 	display_init();
+	// clear
+	display_write(0x01, 0, 0);
+	// display on, no cursor
+	display_write(0x0c, 0, 0);
 
 	// Initialize CAN interface
 	can_init(BITRATE_125_KBPS);
@@ -171,12 +175,52 @@ static void loop() {
 }
 
 static void test() {
-	// clear
-	display_write(0x01, 0, 0);
-	// display on, no cursor
-	display_write(0x0c, 0, 0);
+	static uint8_t test_char = 0;
 	display_write(0x80, (const uint8_t *) "Hello, world", 12);
-	_delay_ms(1000);
+	display_write(0xc0, (const uint8_t *) &test_char, 1);
+	test_char++;
+	_delay_ms(100);
+}
+
+static void test2() {
+	// PC5, PC6, PC7: output (VFD RS, RW, E), RS=0, RW=1, E=1
+	// PD0, PD1, PB0, PB1, PB7, PD5, PD6, PD7: output (VFD DB) - can be switched to input (pullup not needed)
+	PORTC &= ~(_BV(PC5) | _BV(PC6) | _BV(PC7));
+	PORTB &= ~(_BV(PB0) | _BV(PB1) | _BV(PB7));
+	PORTD &= ~(_BV(PD0) | _BV(PD1) | _BV(PD5) | _BV(PD6) | _BV(PD7));
+	PORTC |= _BV(PC5);
+	_delay_us(10);
+	PORTC &= ~_BV(PC5);
+	PORTC |= _BV(PC6);
+	_delay_us(10);
+	PORTC &= ~_BV(PC6);
+	PORTC |= _BV(PC7);
+	_delay_us(10);
+	PORTC &= ~_BV(PC7);
+	PORTD |= _BV(PD0);
+	_delay_us(10);
+	PORTD &= ~_BV(PD0);
+	PORTD |= _BV(PD1);
+	_delay_us(10);
+	PORTD &= ~_BV(PD1);
+	PORTB |= _BV(PB0);
+	_delay_us(10);
+	PORTB &= ~_BV(PB0);
+	PORTB |= _BV(PB1);
+	_delay_us(10);
+	PORTB &= ~_BV(PB1);
+	PORTB |= _BV(PB7);
+	_delay_us(10);
+	PORTB &= ~_BV(PB7);
+	PORTD |= _BV(PD5);
+	_delay_us(10);
+	PORTD &= ~_BV(PD5);
+	PORTD |= _BV(PD6);
+	_delay_us(10);
+	PORTD &= ~_BV(PD6);
+	PORTD |= _BV(PD7);
+	_delay_us(10);
+	PORTD &= ~_BV(PD7);
 }
 
 int main() {