Lots of development of new features. Radio input, motor output, PID control

loops, boot-time initialisation, option to run without attached UART.

And.. it flies!

uart.c

@@ -38,6 +38,8 @@ volatile bool tx_running;
 
 void __attribute__((interrupt("IRQ"))) uart_interrupt_handler(void);
 
+#ifdef USE_UART
+
 void init_uart(void)
 {
 	UREG(FDR) = 0x10; /* DivAddVal = 0, MulVal = 1 */
@@ -205,3 +207,4 @@ bool getch(char *c) {
 	uart_rxread = (uart_rxread + 1) % UART_RXBUFSIZE;
 	return TRUE;
 }
+#endif