Function Scan_setup

Scan/Deprecated/MicroSwitch8304/scan_loop.c:66–94

Setup

// Setup
inline void Scan_setup()
{
	// Setup the the USART interface for keyboard data input
	// NOTE: The input data signal needs to be inverted for the Teensy USART to properly work

	// Setup baud rate
	// 16 MHz / ( 16 * Baud ) = UBRR
	// Baud <- 0.82020 ms per bit, thus 1000 / 0.82020 = 1219.2
	// Thus baud setting = 820
	uint16_t baud = 820; // Max setting of 4095
	UBRR1H = (uint8_t)(baud >> 8);
	UBRR1L = (uint8_t)baud;

	// Enable the receiver, transitter, and RX Complete Interrupt
	UCSR1B = 0x98;

	// Set frame format: 8 data, no stop bits or parity
	// Asynchrounous USART mode
	// 8304 sends encoded scancodes (for example Alphanumeric 0-9 follows their keypad encoding scheme)
	// Separate line is for reset
	UCSR1C = 0x06;

	// Initially buffer doesn't need to be cleared (it's empty...)
	BufferReadyToClear = 0;

	// Reset the keyboard before scanning, we might be in a wierd state
	// Note: This should be run asap, but we need the USART setup to run this command on the 8304
	scan_resetKeyboard();
}


// Main Detection Loop