USB_Mega 调试1 --- 开发板测试

1。买的万用表二极管档输出能力过大，导致所有Mega芯片IO脚对END正向短路，VCC对IO脚正向短路。

2。Mega芯片出厂配置一般为内部时钟1MHz，采用USBasp下载时，要调整USBasp的下载速度（短接跳线），改变熔丝位之后再调回高速。

3。Mega熔丝配置为外部晶体震荡，但是因为没有起震而不能下载时，可从其他芯片X2脚引线到不能下载芯片X1脚。

4。FT232BM安装官网驱动即可识别并有相应的COM口。

5。max232 外面的电容，如果是max232xxA型号全部接0.1u，如果是max232xx型号全部接1uf。在我板子上实验max232cse外接0.1u也是正常的，呵呵。BTW，无极性有机性的均可。 最重要的一点：TTL和RS232电平接口要分清，两套接口的名字画封装的时候很类似，结果两套就接反了，刻断飞线之后还能用，万幸！ 

6。max232的2脚本来接电容到VCC上，但是从原来的一个图利copy过来，2脚经过电容接地貌似也没不正常，哈哈。

7。今天调试，遇到一个坑爹的问题。Mega16在JTAG使能的时候PORTC相关的几个脚（PORTC2，3，4，5）不能当IO用。 对他们的置位将不能达到正常电平。

  使用软件可以禁用JTAG：MCUCSR = 0x80;    但是实验发现此时PORTC3 （TDO）脚仍然不正常，不能当IO脚用。只有当在熔丝位配置里面禁用JTAG之后，JTAGEN=1才正常。

Tips：Mega系列熔丝位1表示未编程，0表示编程。

8.配置开发环境：

  主机：Ubuntu10.10 i386 Desktop edition network availble

  软件： 编译软件avr-gcc; 下载软件：avrdude

  硬件：此开发板，USB转串口线，USB公口转公口线，USBasp下载线，5V电源适配器。

   主芯片：mega8(12Mhz)和Mega16(16Mhz)。

   

如图通过一个双刀双掷开关选择编程Mega8或者Mega16。

10.测试程序： hello，world  && Led

#define F_CPU 16000000

#include <stdio.h>
#include <avr/io.h>
#include <avr/interrupt.h>
#include <avr/wdt.h>
#include <util/delay.h>

#define BIT _BV

void board_test()
{
  DDRC = 0xf0;
  wdt_disable();
  while(1)
  {
    _delay_ms(500);
    PORTC |= 0xf0;

    _delay_ms(500);
    PORTC &= 0x0f;
  }
}
void init_port()
{
  DDRC  = 0xf0;
  PORTC = 0x00;

  DDRD  = 0x02;
  PORTD = 0x00;

  DDRA  = 0x00;
  DDRB  = 0x00;
}

void put_char(char c)
{
  while ( !(UCSRA & (1<<UDRE)) ) ;
  UDR = c;
}

void init_uart()
{
 UCSRB = 0x00;
 UCSRA = 0x00;
 UCSRC = BIT(URSEL) | 0x06;
 UBRRL = 0x67; //set baud rate lo
 UBRRH = 0x00; //set baud rate hi
 UCSRB = 0x18;

 
 void init_device()
{
  init_port();
  init_uart();
}


int main()
{
  init_device();
  //board_test();

  put_char('a');
  put_char('a');
  put_char('a');
  while(1);
  return 0;
}

Makfile:

#       Makefile for myUsb_Mega
#       Based on:
#
#   Makefile for usbasp
#   20061119   Thomas Fischl        original
#   20061120   Hanns-Konrad Unger   help: and TARGET=atmega48 added
#



TARGET=atmega16
HFUSE=0xc9
LFUSE=0x2f


# ISP=bsd      PORT=/dev/parport0
# ISP=ponyser  PORT=/dev/ttyS1
# ISP=stk500   PORT=/dev/ttyS1
# ISP=usbasp   PORT=/dev/usb/ttyUSB0
# ISP=stk500v2 PORT=/dev/ttyUSB0
ISP=usbasp
PORT=/dev/usb/ttyUSB0

help:
        @echo "Usage: make                same as make help"
        @echo "       make help           same as make"
        @echo "       make main.hex       create main.hex"
        @echo "       make clean          remove redundant data"
        @echo "       make disasm         disasm main"
        @echo "       make flash          upload main.hex into flash"
        @echo "       make fuses          program fuses"
        @echo "       make avrdude        test avrdude"
        @echo "Current values:"
        @echo "       TARGET=${TARGET}"
        @echo "       LFUSE=${LFUSE}"
        @echo "       HFUSE=${HFUSE}"
        @echo "       CLOCK=16MHz"
        @echo "       ISP=${ISP}"
        @echo "       PORT=${PORT}"

COMPILE = avr-gcc -Wall -O2 -I. -mmcu=$(TARGET) # -DDEBUG_LEVEL=2

OBJECTS = main.o # isp.o clock.o tpi.o

.c.o:
        $(COMPILE) -c $< -o $@
#-Wa,-ahlms=$<.lst

.S.o:
        $(COMPILE) -x assembler-with-cpp -c $< -o $@
# "-x assembler-with-cpp" should not be necessary since this is the default
# file type for the .S (with capital S) extension. However, upper case
# characters are not always preserved on Windows. To ensure WinAVR
# compatibility define the file type manually.

.c.s:
        $(COMPILE) -S $< -o $@

clean:
        rm -f main.hex main.lst main.obj main.cof main.list main.map main.eep.hex main.bin *.o main.s

# file targets:
main.bin:       $(OBJECTS)
        $(COMPILE) -o main.bin $(OBJECTS) -Wl,-Map,main.map

main.hex:       main.bin
        rm -f main.hex main.eep.hex
        avr-objcopy -j .text -j .data -O ihex main.bin main.hex
#       ./checksize main.bin
# do the checksize script as our last action to allow successful compilation
# on Windows with WinAVR where the Unix commands will fail.


disasm: main.bin
        avr-objdump -d main.bin

cpp:
        $(COMPILE) -E main.c

flash:
        avrdude -c ${ISP} -p ${TARGET} -P ${PORT} -U flash:w:main.hex

fuses:
        avrdude -c ${ISP} -p ${TARGET} -P ${PORT} -u -U hfuse:w:$(HFUSE):m -U lfuse:w:$(LFUSE):m

avrdude:
        avrdude -c ${ISP} -p ${TARGET} -P ${PORT} -v

# Fuse atmega16 high byte HFUSE:
# 0xc9 = 1 1 0 0   1 0 0 1 <-- BOOTRST (boot reset vector at 0x0000)
#        ^ ^ ^ ^   ^ ^ ^------ BOOTSZ0
#        | | | |   | +-------- BOOTSZ1
#        | | | |   + --------- EESAVE (don't preserve EEPROM over chip erase)
#        | | | +-------------- CKOPT (full output swing)
#        | | +---------------- SPIEN (allow serial programming)
#        | +------------------ JTAGEN
#        +-------------------- RSTDISBL (reset pin is enabled)
# Fuse atmega16 low byte LFUSE:
# 0x9f = 1 0 0 1   1 1 1 1
#        ^ ^ \ /   \--+--/
#        | |  |       +------- CKSEL 3..0 (external >8M crystal)
#        | |  +--------------- SUT 1..0 (crystal osc, BOD enabled)
#        | +------------------ BODEN (BrownOut Detector enabled)
#        +-------------------- BODLEVEL (2.7V)
#
# Fuse atmega48 high byte hfuse:
# 0xdf = 1 1 0 1   1 1 1 1     factory setting
#        ^ ^ ^ ^   ^ \-+-/
#        | | | |   |   +------ BODLEVEL (Brown out disabled)
#        | | | |   + --------- EESAVE (don't preserve EEPROM over chip erase)
#        | | | +-------------- WDTON (WDT not always on)
#        | | +---------------- SPIEN (allow serial programming)
#        | +------------------ DWEN (debug wire is disabled)
#        +-------------------- RSTDISBL (reset pin is enabled)
# 0xdd = ext.reset, no DW, SPI, no watchdog, no save eeprom, BOD 2.7V
# Fuse atmega48 low byte lfuse:
# 0x62 = 0 1 1 0   0 0 1 0     factory setting
#        ^ ^ \ /   \--+--/
#        | |  |       +------- CKSEL 3..0 (internal 8Mhz Oszillator)
#        | |  +--------------- SUT 1..0 (start-up time)
#        | +------------------ CKOUT (no clock output)
#        +-------------------- CKDIV8 (divide clock by 8)
# 0xdc = divide/1,no clock output,fast raising power,low Pw Oszil. 3..8 Mhz
# 0xe0 = divide/1,no clock output,fast raising power,external Oszil.
# 0xff = divide/1,no clock output,slow raising power,low Pw Oszil 8..  Mhz


SERIAL = `echo /dev/tty.USA19QI*`
UISP = uisp -dprog=$S -dserial=$(SERIAL) -dpart=auto
# The two lines above are for "uisp" and the AVR910 serial programmer connected
# to a Keyspan USB to serial converter to a Mac running Mac OS X.
# Choose your favorite programmer and interface.

uisp:   all
        $(UISP) --erase
        $(UISP) --upload --verify if=main.hex

Windows:   

//ICC-AVR application builder : 2011-11-22 9:39:42
// Target : M16
// Crystal: 16.000Mhz

#include <iom16v.h>
#include <macros.h>
#include <stdio.h>

 
extern int _textmode;
 
int putchar(char c)
    {
    if (_textmode && c == '\n')
        putchar('\r');
    /* Wait for empty transmit buffer */
    while ( !(UCSRA & (1<<UDRE)) )
        ;                     
    /* Putting data into buffer , sends the data */
    UDR = c;  
    return c;
    }

void port_init(void)
{
 PORTA = 0x00;
 DDRA  = 0x00;
 PORTB = 0x00;
 DDRB  = 0x00;
 PORTC = 0x00; //m103 output only
 DDRC  = 0x00;
 PORTD = 0x00;
 DDRD  = 0x02;
}

//UART0 initialize
// desired baud rate: 9600
// actual: baud rate:9615 (0.2%)
void uart0_init(void)
{
 UCSRB = 0x00; //disable while setting baud rate
 UCSRA = 0x00;
 UCSRC = BIT(URSEL) | 0x06;
 UBRRL = 0x67; //set baud rate lo
 UBRRH = 0x00; //set baud rate hi
 UCSRB = 0x18;
}

//call this routine to initialize all peripherals
void init_devices(void)
{
 //stop errant interrupts until set up
 CLI(); //disable all interrupts
 port_init();
 uart0_init();

 MCUCR = 0x00;
 GICR  = 0x00;
 TIMSK = 0x00; //timer interrupt sources
 SEI(); //re-enable interrupts
 //all peripherals are now initialized
}

void main()
{
  init_devices();
  
  printf("Hello,world!\r\n");
  while(1);
}

//ICC-AVR application builder : 2011-11-22 9:46:32
// Target : M8
// Crystal: 12.000Mhz

#include <iom8v.h>
#include <macros.h>
#include <stdio.h>


extern int _textmode;
 
int putchar(char c)
    {
    if (_textmode && c == '\n')
        putchar('\r');
    /* Wait for empty transmit buffer */
    while ( !(UCSRA & (1<<UDRE)) )
        ;                     
    /* Putting data into buffer , sends the data */
    UDR = c;  
    return c;
    }

void port_init(void)
{
 PORTB = 0x00;
 DDRB  = 0x00;
 PORTC = 0x00; //m103 output only
 DDRC  = 0x00;
 PORTD = 0x00;
 DDRD  = 0x02;
}

//UART0 initialize
// desired baud rate: 9600
// actual: baud rate:9615 (0.2%)
void uart0_init(void)
{
 UCSRB = 0x00; //disable while setting baud rate
 UCSRA = 0x00;
 UCSRC = BIT(URSEL) | 0x06;
 UBRRL = 0x4D; //set baud rate lo
 UBRRH = 0x00; //set baud rate hi
 UCSRB = 0x18;
}

//call this routine to initialize all peripherals
void init_devices(void)
{
 //stop errant interrupts until set up
 CLI(); //disable all interrupts
 port_init();
 uart0_init();

 MCUCR = 0x00;
 GICR  = 0x00;
 TIMSK = 0x00; //timer interrupt sources
 SEI(); //re-enable interrupts
 //all peripherals are now initialized
}

void main()
{
  init_devices();
  
  printf("Hello,world!\r\n");
  while(1);
}

总结：这次的板子除了串口芯片接错线外，电源的设计也不是很方便。原来想着电源输入之后经过7805稳压共给下面的芯片。但是手边都是220V转5V的电源，没找到7v之上的适配器。最后还是把7805短接了才能用5V的适配器。以后样板可以考虑加个开关或者调线。

板子整体来说还是蛮不错的~~ 嘻嘻......