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Thread: USb MIDI coding

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  1. #1
    Junior Member
    Join Date
    Apr 2014
    Posts
    2

    USb MIDI coding

    Hi i have a teensy 2.0 with ATMEGA32U4 i have been trying to convert the teensy arduino midi library so it can be used directly like Usb serial / keyboard examples in the "Code Library" selection on the teensy website.

    The main reason for doing this without the arduino is so i can swap USB device profile on startup acording to some dip switches ie be able to choose usb midi , keyboard , serial port .



    The problem im having is i can Initialize the USB midi but i can't seem to write anything out.


    My code compiles fine in AVR studio with no errors and my computer sees a usb midi device but cant seem to get anything to write out.


    Below is how im trying to test it

    Code:
    
    
    int main(void)
    
    
    {
    	
    usb_init();   // this must be ok as computer sees "USB midi"
    	
    _delay_ms(1000);
    	
    	
        while(1)
        {
    		
    	sendControlChange(16,255,1);
    		
    		
    
       
       
      }

    Bellow are the functions i thought are relevant missing out include files and definitions ect

    I basically just took sendControlChange() and send_raw() out of the arduino usb_api.cpp



    Code:
    
    
    // initialize USB serial
    void usb_init(void)
    {
    	uint8_t u;
    
    	u = USBCON;
    	if ((u & (1<<USBE)) && !(u & (1<<FRZCLK))) return;
    	HW_CONFIG();
            USB_FREEZE();				// enable USB
            PLL_CONFIG();				// config PLL
            while (!(PLLCSR & (1<<PLOCK))) ;	// wait for PLL lock
            USB_CONFIG();				// start USB clock
            UDCON = 0;				// enable attach resistor
    	usb_configuration = 0;
    	usb_suspended = 0;
    	debug_flush_timer = 0;
    	UDINT = 0;
            UDIEN = (1<<EORSTE)|(1<<SOFE);
    	sei();  // init() in wiring.c does this
    }
    
    
    
    
    
    
    
    
    void sendControlChange(uint8_t control, uint8_t value, uint8_t channel)
    {
    	send_raw(0x0B, 0xB0 | ((channel - 1) & 0x0F), control & 0x7F, value & 0x7F);
    }
    
    
    
    
    void send_raw(uint8_t b0, uint8_t b1, uint8_t b2, uint8_t b3)
    {
    	uint8_t intr_state, timeout;
    
    	if (!usb_configuration) return;
    	intr_state = SREG;
    	cli();
    	UENUM = MIDI_TX_ENDPOINT;
    	timeout = UDFNUML + 2;
    	while (1) {
    		// are we ready to transmit?
    		if (UEINTX & (1<<RWAL)) break;
    		SREG = intr_state;
    		if (UDFNUML == timeout) return;
    		if (!usb_configuration) return;
    		intr_state = SREG;
    		cli();
    		UENUM = MIDI_TX_ENDPOINT;
    	}
    	UEDATX = b0;
    	UEDATX = b1;
    	UEDATX = b2;
    	UEDATX = b3;
    	if (!(UEINTX & (1<<RWAL))) UEINTX = 0x3A;
    	SREG = intr_state;
    }
    
    
    
    
    ISR(USB_GEN_vect)
    {
    	uint8_t intbits, t, i;
    	static uint8_t div4=0;
    
            intbits = UDINT;
            UDINT = 0;
            if (intbits & (1<<EORSTI)) {
    		UENUM = 0;
    		UECONX = 1;
    		UECFG0X = EP_TYPE_CONTROL;
    		UECFG1X = EP_SIZE(ENDPOINT0_SIZE) | EP_SINGLE_BUFFER;
    		UEIENX = (1<<RXSTPE);
    		usb_configuration = 0;
            }
            if ((intbits & (1<<SOFI)) && usb_configuration) {
                    t = debug_flush_timer;
                    if (t) {
                            debug_flush_timer = --t;
                            if (!t) {
                                    UENUM = DEBUG_TX_ENDPOINT;
                                    while ((UEINTX & (1<<RWAL))) {
                                            UEDATX = 0;
                                    }
                                    UEINTX = 0x3A;
                            }
                    }
                    UENUM = MIDI_TX_ENDPOINT;
    		if (UEBCLX) UEINTX = 0x3A;
            }
    	if (intbits & (1<<SUSPI)) {
    		// USB Suspend (inactivity for 3ms)
    		UDIEN = (1<<WAKEUPE);
    		usb_configuration = 0;
    		usb_suspended = 1;
    		#if (F_CPU >= 8000000L)
    		// WAKEUPI does not work with USB clock freeze 
    		// when CPU is running less than 8 MHz.
    		// Is this a hardware bug?
    		USB_FREEZE();			// shut off USB
    		PLLCSR = 0;			// shut off PLL
    		#endif
    		// to properly meet the USB spec, current must
    		// reduce to less than 2.5 mA, which means using
    		// powerdown mode, but that breaks the Arduino
    		// user's paradigm....
    	}
    	if (usb_suspended && (intbits & (1<<WAKEUPI))) {
    		// USB Resume (pretty much any activity)
    		#if (F_CPU >= 8000000L)
    		PLL_CONFIG();
    		while (!(PLLCSR & (1<<PLOCK))) ;
    		USB_CONFIG();
    		#endif
    		UDIEN = (1<<EORSTE)|(1<<SOFE)|(1<<SUSPE);
    		usb_suspended = 0;
    		return;
    	}
    }
    
    
    // Misc functions to wait for ready and send/receive packets
    static inline void usb_wait_in_ready(void)
    {
    	while (!(UEINTX & (1<<TXINI))) ;
    }
    static inline void usb_send_in(void)
    {
    	UEINTX = ~(1<<TXINI);
    }
    static inline void usb_wait_receive_out(void)
    {
    	while (!(UEINTX & (1<<RXOUTI))) ;
    }
    static inline void usb_ack_out(void)
    {
    	UEINTX = ~(1<<RXOUTI);
    }
    
    
    
    // USB Endpoint Interrupt - endpoint 0 is handled here.  The
    // other endpoints are manipulated by the user-callable
    // functions, and the start-of-frame interrupt.
    //
    ISR(USB_COM_vect)
    {
            uint8_t intbits;
    	const uint8_t *list;
            const uint8_t *cfg;
    	uint8_t i, n, len, en;
    	uint8_t *p;
    	uint8_t bmRequestType;
    	uint8_t bRequest;
    	uint16_t wValue;
    	uint16_t wIndex;
    	uint16_t wLength;
    	uint16_t desc_val;
    	const uint8_t *desc_addr;
    	uint8_t	desc_length;
    
    	UENUM = 0;
    	intbits = UEINTX;
    	if (intbits & (1<<RXSTPI)) {
    		bmRequestType = UEDATX;
    		bRequest = UEDATX;
    		read_word_lsbfirst(wValue, UEDATX);
    		read_word_lsbfirst(wIndex, UEDATX);
    		read_word_lsbfirst(wLength, UEDATX);
    		UEINTX = ~((1<<RXSTPI) | (1<<RXOUTI) | (1<<TXINI));
    		if (bRequest == GET_DESCRIPTOR) {
    			list = (const uint8_t *)descriptor_list;
    			for (i=0; ; i++) {
    				if (i >= NUM_DESC_LIST) {
    					UECONX = (1<<STALLRQ)|(1<<EPEN);  //stall
    					return;
    				}
    				pgm_read_word_postinc(desc_val, list);
    				if (desc_val != wValue) {
    					list += sizeof(struct descriptor_list_struct)-2;
    					continue;
    				}
    				pgm_read_word_postinc(desc_val, list);
    				if (desc_val != wIndex) {
    					list += sizeof(struct descriptor_list_struct)-4;
    					continue;
    				}
    				pgm_read_word_postinc(desc_addr, list);
    				desc_length = pgm_read_byte(list);
    				break;
    			}
    			len = (wLength < 256) ? wLength : 255;
    			if (len > desc_length) len = desc_length;
    			list = desc_addr;
    			do {
    				// wait for host ready for IN packet
    				do {
    					i = UEINTX;
    				} while (!(i & ((1<<TXINI)|(1<<RXOUTI))));
    				if (i & (1<<RXOUTI)) return;	// abort
    				// send IN packet
    				n = len < ENDPOINT0_SIZE ? len : ENDPOINT0_SIZE;
    				for (i = n; i; i--) {
    					pgm_read_byte_postinc(UEDATX, list);
    				}
    				len -= n;
    				usb_send_in();
    			} while (len || n == ENDPOINT0_SIZE);
    			return;
                    }
    		if (bRequest == SET_ADDRESS) {
    			usb_send_in();
    			usb_wait_in_ready();
    			UDADDR = wValue | (1<<ADDEN);
    			return;
    		}
    		if (bRequest == SET_CONFIGURATION && bmRequestType == 0) {
    			usb_configuration = wValue;
    			debug_flush_timer = 0;
    			usb_send_in();
    			cfg = endpoint_config_table;
    			for (i=1; i<NUM_ENDPOINTS; i++) {
    				UENUM = i;
    				pgm_read_byte_postinc(en, cfg);
    				UECONX = en;
    				if (en) {
    					pgm_read_byte_postinc(UECFG0X, cfg);
    					pgm_read_byte_postinc(UECFG1X, cfg);
    				}
    			}
            		UERST = 0x1E;
            		UERST = 0;
    			return;
    		}
    		if (bRequest == GET_CONFIGURATION && bmRequestType == 0x80) {
    			usb_wait_in_ready();
    			UEDATX = usb_configuration;
    			usb_send_in();
    			return;
    		}
    		if (bRequest == GET_STATUS) {
    			usb_wait_in_ready();
    			i = 0;
    			if (bmRequestType == 0x82) {
    				UENUM = wIndex;
    				if (UECONX & (1<<STALLRQ)) i = 1;
    				UENUM = 0;
    			}
    			UEDATX = i;
    			UEDATX = 0;
    			usb_send_in();
    			return;
    		}
    		if ((bRequest == CLEAR_FEATURE || bRequest == SET_FEATURE)
    		  && bmRequestType == 0x02 && wValue == 0) {
    			i = wIndex & 0x7F;
    			if (i >= 1 && i <= MAX_ENDPOINT) {
    				usb_send_in();
    				UENUM = i;
    				if (bRequest == SET_FEATURE) {
    					UECONX = (1<<STALLRQ)|(1<<EPEN);
    				} else {
    					UECONX = (1<<STALLRQC)|(1<<RSTDT)|(1<<EPEN);
    					UERST = (1 << i);
    					UERST = 0;
    				}
    				return;
    			}
    		}
                    if (wIndex == DEBUG_INTERFACE) {
                            if (bRequest == HID_GET_REPORT && bmRequestType == 0xA1) {
                                    len = wLength;
                                    do {
                                            // wait for host ready for IN packet
                                            do {
                                                    i = UEINTX;
                                            } while (!(i & ((1<<TXINI)|(1<<RXOUTI))));
                                            if (i & (1<<RXOUTI)) return;    // abort
                                            // send IN packet
                                            n = len < ENDPOINT0_SIZE ? len : ENDPOINT0_SIZE;
                                            for (i = n; i; i--) {
                                                    UEDATX = 0;
                                            }
                                            len -= n;
                                            usb_send_in();
                                    } while (len || n == ENDPOINT0_SIZE);
                                    return;
                            }
                            if (bRequest == HID_SET_REPORT && bmRequestType == 0x21) {
    				if (wValue == 0x0300 && wLength == 0x0004) {
    					uint8_t b1, b2, b3, b4;
                                            usb_wait_receive_out();
    					b1 = UEDATX;
    					b2 = UEDATX;
    					b3 = UEDATX;
    					b4 = UEDATX;
                                            usb_ack_out();
                                            usb_send_in();
    					//if (b1 == 0xA9 && b2 == 0x45 && b3 == 0xC2 && b4 == 0x6B)
    						//_reboot_Teensyduino_();
    					//if (b1 == 0x8B && b2 == 0xC5 && b3 == 0x1D && b4 == 0x70)
    						//_restart_Teensyduino_();
    				}
    			}
                    }
            }
    	UECONX = (1<<STALLRQ) | (1<<EPEN);	// stall
    }

    Any help or advice would be great as not sure where im going wrong.


    Cheers for looking

    Luke
    Last edited by lukes27; 04-22-2014 at 01:43 PM.

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