1 files changed, 92 insertions, 0 deletions
diff --git a/port.c b/port.c
new file mode 100644
index 0000000..91e3a8c
--- /dev/null
+++ b/port.c
@@ -0,0 +1,92 @@
+#include "casio-get.h"
+
+#define PACKET_WAIT_PER_BYTE 	2
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <libserialport.h>
+
+/******************************************************************************
+ * Wait for the calculator to request a data transfer
+ ******************************************************************************/
+void wait_calc(struct sp_port *port)
+{
+	char buf[1];
+	int read;
+	fprintf(stderr, "Waiting for calculator... ");
+	while((read = sp_blocking_read(port, buf, 1, 0)) > 0)
+	{
+		if (buf[0] == ATTENTION_REQ)
+			break;
+	}
+
+	if (read <= 0)
+		serial_error("sp_blocking_read");
+
+	fprintf(stderr, "transfer request received!\n");
+}
+
+
+/******************************************************************************
+ * Send single byte to calculator
+ ******************************************************************************/
+void send_calc_byte(struct sp_port *port, const char val)
+{
+	char data[1];
+	data[0] = val;
+	if (sp_blocking_write(port, data, 1, 0) != 1)
+		serial_error("sp_blocking_write");
+}
+
+enum sp_return calc_read(struct sp_port *port, unsigned char* buffer, size_t size)
+{
+	enum sp_return ret = sp_blocking_read(port, buffer, size, PACKET_WAIT_PER_BYTE*size);
+	if (ret < 0)
+		serial_error("sp_blocking_read");
+
+	return ret;
+}
+
+
+/******************************************************************************
+ * Open and initialise serial port
+ ******************************************************************************/
+struct sp_port* port_init(const char* device)
+{
+	struct sp_port* port;
+	if (sp_get_port_by_name(device, &port) != SP_OK)
+		serial_error("sp_get_port_by_name");
+
+	if (sp_open(port, SP_MODE_READ|SP_MODE_WRITE) != SP_OK)
+		serial_error("sp_open");
+
+
+	/* Port config is more or less hard-coded
+	   The Casio calcs operate at 9600,8N with 2 stop bits RX
+	   and 1 stop bit TX but 2 stop bits both ways can't hurt :) */
+	if (sp_set_baudrate(port, 9600) != SP_OK)
+		serial_error("sp_set_baudrate");
+
+	if (sp_set_parity(port, SP_PARITY_NONE) != SP_OK)
+		serial_error("sp_set_parity");
+
+	if (sp_set_bits(port, 8) != SP_OK)
+		serial_error("sp_set_bits");
+
+	if (sp_set_stopbits(port, 1) != SP_OK)
+		serial_error("sp_set_stopbits");
+
+	if (sp_set_flowcontrol(port, SP_FLOWCONTROL_NONE) != SP_OK)
+		serial_error("sp_set_flowcontrol");
+
+	if (sp_set_xon_xoff(port, SP_XONXOFF_DISABLED) != SP_OK)
+		serial_error("sp_set_xon_xoff");
+
+	if (sp_set_dtr(port, SP_DTR_ON) != SP_OK)
+		serial_error("sp_set_dtr");
+
+	if (sp_set_rts(port, SP_RTS_OFF) != SP_OK)
+		serial_error("sp_set_rts");
+
+	return port;
+}