参考:
- Atmel AVR
Atmel AVR系列是一种基于改进的哈佛结构、8位～32位精简指令集(Reduced Instruction Set Computing,RISC)的微控制器,由Atmel公司于1996年研发.AVR系列是首次采用闪存(Flash Memory)作为数据存储介质的单芯片微控制器之一,同时代的其它微控制器多采用一次写入可编程ROM、EPROM或是EEPROM.目前AVR处理器发展了六个系列,分别是:tinyAVR,ATtiny系列;megaAVR,ATmega系列;XMEGA,ATxmega系列;Application-specific AVR,面向特殊应用的AVR系列,增加LCD控制器、USB控制器、PWM等特性;FPSLIC,FPGA上的AVR核;AVR32,32位AVR系列,包含SIMD和DSP以及音视频处理特性,与ARM架构形成争.

ATmega32U4(Arduino pro micro)

sparkfun/Arduino_Boards
atmega-asm
MiniCore
Arduino-Based (ATmega32U4) Mouse and Keyboard Controller
The Lost Art of Structure Packing

连接ICSP烧写bootloader.

        (2232HIO)
        FT232H              ATmega32U4

    pin13 ADBUS0   <------>   SCK    pin15
    pin14 ADBUS1   <------>   MOSI   pin16
    pin15 ADBUS2   <------>   MISO   pin14
    pin16 ADBUS3   <------>   Reset  RST
            GND    <------>   GND
          +3.3V    <------>   +3.3V

~$ avrdude -C /etc/avrdude.conf -c UM232H -P /dev/ttyUSB0 -b 19200 -p atmega32u4  -U lfuse:r:-:i

avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.01s

avrdude: Device signature = 0x1e9587 (probably m32u4)
avrdude: reading lfuse memory:

Reading | ################################################## | 100% 0.00s

avrdude: writing output file "<stdout>"
:01000000FF00
:00000001FF

avrdude: safemode: Fuses OK (E:CB, H:D8, L:FF)

avrdude done.  Thank you.

some of valid programmers for FTDI

2232HIO          = FT2232H based generic programmer
4232h            = FT4232H based generic programmer
ft232r           = FT232R Synchronous BitBang
ft245r           = FT245R Synchronous BitBang
ttl232r          = FTDI TTL232R-5V with ICSP adapter
UM232H           = FT232H based module from FTDI and Glyn.com.au

添加sparkfun/Arduino_Boards,让Arduino IDE支持更多的种类的板子,添加URL后,通过Tools -> Boards Manager 安装SparkFun AVR Boards.烧写SparkFun bootloader.

~$ avrdude -C /etc/avrdude.conf -c UM232H -P /dev/ttyUSB0 -b 19200 -p m32u4  -U flash:w:.arduino15/packages/SparkFun/hardware/avr/1.1.13/bootloaders/caterina/Caterina-promicro16.hex

avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.01s

avrdude: Device signature = 0x1e9587 (probably m32u4)
avrdude: NOTE: "flash" memory has been specified, an erase cycle will be performed
         To disable this feature, specify the -D option.
avrdude: erasing chip
avrdude: reading input file ".arduino15/packages/SparkFun/hardware/avr/1.1.13/bootloaders/caterina/Caterina-promicro16.hex"
avrdude: input file .arduino15/packages/SparkFun/hardware/avr/1.1.13/bootloaders/caterina/Caterina-promicro16.hex auto detected as Intel Hex
avrdude: writing flash (32762 bytes):

Writing | ################################################## | 100% 0.00s

avrdude: 32762 bytes of flash written
avrdude: verifying flash memory against .arduino15/packages/SparkFun/hardware/avr/1.1.13/bootloaders/caterina/Caterina-promicro16.hex:
avrdude: load data flash data from input file .arduino15/packages/SparkFun/hardware/avr/1.1.13/bootloaders/caterina/Caterina-promicro16.hex:
avrdude: input file .arduino15/packages/SparkFun/hardware/avr/1.1.13/bootloaders/caterina/Caterina-promicro16.hex auto detected as Intel Hex
avrdude: input file .arduino15/packages/SparkFun/hardware/avr/1.1.13/bootloaders/caterina/Caterina-promicro16.hex contains 32762 bytes
avrdude: reading on-chip flash data:

Reading | ################################################## | 100% 0.00s

avrdude: verifying ...
avrdude: 32762 bytes of flash verified

avrdude: safemode: Fuses OK (E:CB, H:D8, L:FF)

avrdude done.  Thank you.

ATmega328p (Arduino Pro mini with CH340)

烧写好bootloader就可以使用USB在Arduino IDE上进行开发.
选择Tools -> Board -> Arduino Pro or Pro Mini, 烧写器AVRISP mkii.

`UART`通信的要点

不像其他的通讯协议，UART沒有clock信号可供参考，所以双方需要事先知道彼此的baud rate，才知道双方是以多快的速度传送数据,必须条件：
- 两个硬件设备必须要共地(GND)
- Baud rate必须相同。
Baud rate为9600，每个bit的时间应该是1/9600秒，对于CPU来说是几个cycle呢？如果CPU频率是9600Hz，这样刚好就是1 cycle传输一个bit.

ATtiny85(CJMCU)

Links:
- ATTiny10IDE
- [Tutorial : How to program the CJMCU ATTiny85 (LilyTiny / LilyPad)](https://diyprojects.io/ tutorial-program-cjmcu-attiny85-lilytiny-lilypad/)
- Digispark DIY: the Smallest USB Arduino
- Tiny AVR Programmer Hookup Guide
- Arduino / AVR #
- Little Wire
- ATtiny85 I2C protocol tutorial
- ATtiny85 Snake Game Handheld
- MiniCore

Bootloader

ATtiny85 USB Boot Loader: Details

micronucleus是一个可以支持跨平台的USB上传烧写的bootloader,体积在2kb以内.


        FT232H              ATTiny85

    pin13 ADBUS0   <------>   SCK    PB2
    pin14 ADBUS1   <------>   MOSI   PB0
    pin15 ADBUS2   <------>   MISO   PB1
    pin16 ADBUS3   <------>   Reset  PB5
            GND    <------>   GND
            +5V    <------>   +5V

~ micronucleus/firmware/releases$ avrdude -C /etc/avrdude.conf -c UM232H -P /dev/ttyUSB1 -b 19200 -p attiny85 -U flash:w:t85_default.hex -U lfuse:w:0xe2:m -U hfuse:w:0xdd:m -U efuse:w:0xfe:m

接入USB会发现如下的设备:

~$ lsusb
[...]
Bus 004 Device 007: ID 16d0:0753 MCS Digistump DigiSpark
[...]

复制micronucleus/commandline/49-micronucleus.rules到系统的/etc/udev/rules.d/目录内.

系统控制与复位

这里要讲到关于熔丝位(fuse)的技术.具体的技术细节需要查看Datasheet的20. Memory Programming.可以根据文档去配置编程使能相应的字节的位.也可以通过这个https://www.engbedded.com/fusecalc/配置得出三个字节去配置熔丝位.lfuse表示低位,hfuse表示高位,efuse表示扩展位.
在配置编程熔丝位时有几个问题要注意,比如:把SPIEN,JTAGEN的位设定为未编程状态,这将使芯片失去了JTAG与SPI接口的功能,不能重新烧写,从而以致单片机锁死,出现这种情况时就需要高压(12v)并行编程方式才能将单片机的功能恢复.另一个问题是要启动地址的错误,如果没有开启单片机的BOOTLOADER功能,就不要设置BOOTRST的编程位为0(已编程),否则单片机在上电时不是从Flash的0x0000开始运行的,而是转到BOOT区执行,从而导致单片机无法正确运行.

使用`Arduino IDE`支持(ATTinyCore)

ATTinyCore是让最新的Arduino IDE支持ATTiny系列的单片机,安装流程当然也就是按照https://github.com/SpenceKonde/ATTinyCore/blob/master/Installation.md操作,在Arduino IDE -> File->Preferences加入http://drazzy.com/package_drazzy.com_index.json,并且更新安装ATTinyCore的库.之后在``Arduino IDE -> Tools -> Board -> ATTinyCore`里面可以选择目标的单片机.
有可能ATTinyCore自带的micronucleus版本太低与Attiny85内烧写版本的不匹配,就会出现下面的错误,具体的版本可以查看~/.arduino15/packages/ATTinyCore/tools/micronucleus/2.0a4/.关于ATTinyCore所支持的硬件与固件配置可以查看~/.arduino15/packages/ATTinyCore/hardware/avr/1.4.1/bootloaders.

1
2
3

Warning: device with unknown new version of Micronucleus detected.
This tool doesn\'t know how to upload to this new device. Updates may be available.
Device reports version as: 2.4

关于上面的警告提示,需要更新micronucleus版本.

1 2	~$ cd micronucleus/commandline && make ~$ cp micronucleus ~/.arduino15/packages/ATTinyCore/tools/micronucleus/2.0a4/

使用`Arduino`上传第一个程序(blink).

选择主板:Tools -> Board -> ATTinyCore -> ATtiny85(Micronucleus/DigiSpark)
烧写方式:Tools -> Burn Bootloader Method: "Upgrade (via USB)"
基本上选择了正确的主板,其它参数默认就可以了,测试图如下:

测式程序是:File -> Examples -> Built-in examples -> 01.Basics -> Blink. 只是重定义了LED_BUILTIN的IO口,如下:

#define LED_BUILTIN 1

// the setup function runs once when you press reset or power the board
void setup() {
  // initialize digital pin LED_BUILTIN as an output.
  pinMode(LED_BUILTIN, OUTPUT);
}

// the loop function runs over and over again forever
void loop() {
  digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);                       // wait for a second
  digitalWrite(LED_BUILTIN, LOW);    // turn the LED off by making the voltage LOW
  delay(1000);                       // wait for a second
}

烧写提示如下:

Plug in device now... (will timeout in 60 seconds)
> Please plug in the device ...
> Press CTRL+C to terminate the program.
> Device is found!
connecting: 16% complete
connecting: 22% complete
connecting: 28% complete
connecting: 33% complete
> Device has firmware version 2.4
> Device signature: 0x1e930b
> Available space for user applications: 6522 bytes
> Suggested sleep time between sending pages: 7ms
> Whole page count: 102  page size: 64
> Erase function sleep duration: 714ms
parsing: 50% complete
> Erasing the memory ...
erasing: 55% complete
erasing: 60% complete
erasing: 65% complete
> Starting to upload ...
writing: 70% complete
writing: 75% complete
writing: 80% complete
> Starting the user app ...
running: 100% complete
>> Micronucleus done. Thank you!

新增烧写器(UM232H为例)

Platform specification

~$ tree -L 2 ~/.arduino15/packages/
/home/michael/.arduino15/packages/
├── arduino
│   ├── hardware
│   └── tools
├── atmel-avr-xminis
│   └── hardware
├── ATTinyCore
│   ├── hardware
│   └── tools
├── esp32
│   ├── hardware
│   └── tools
├── SparkFun
│   └── hardware
└── STM32
    ├── hardware
    └── tools

在~/.arduino15/packages/内的各种包内结构如下,基本每一个包(package: i.e: ardunion,ATTinyCore )下面的hardware\<arch>\<version\内都有boards.txt,programmers.txt文件.
而在包下面的hardware\tools\内包内,包含这个包所支持的工具链,如:编译器,烧写器,还有一些特定的工具等.这里以avrdude为例,在Arduino IDE烧写AVR的板子时候,它会调用包内的avrdude与配置文件,如:

1 2	.arduino15/packages/arduino/tools/avrdude/6.3.0-arduino17/bin/avrdude \ -c .arduino15/packages/arduino/tools/avrdude/6.3.0-arduino17/etc/avrdude.conf

下面是让ATTinyCore包内的Attiny85通过使用UM232H烧写器,在Arduino IDE内烧写,无需其它的bootloader支持.
首先在~/.arduino15/packages/ATTinyCore/hardware/avr/1.4.1/programmers.txt内,加入以下内容:

um232h.name=UM232H as ISP
um232h.communication=serial
um232h.protocol=UM232H
um232h.speed=19200
um232h.program.protocol=UM232H
um232h.program.speed=19200
um232h.program.tool=avrdude
um232h.program.extra_params=-P{serial.port} -b{program.speed}

重启Arduino IDE会发现,选择ATTinyCore包类的板子,在烧写器一栏,会看到UM232H as ISP. 如果在某个包类没有在定义programmers.txt,它就会使用目标板子在arduino体系内所对应~/.arduino15/packages/arduino/hardware/<arch>/<version>/programmers.txt

如:

1	~$ .arduino15/packages/arduino/tools/avrdude/6.3.0-arduino17/bin/avrdude -C .arduino15/packages/ATTinyCore/hardware/avr/1.4.1/avrdude.conf

如果这里的.arduino15/packages/ATTinyCore/hardware/avr/1.4.1/avrdude.conf文件内没有支持UM232H配置,需要在avrdude.conf加入下面内容:

# UM232H module from FTDI and Glyn.com.au.
# See helix.air.net.au for detailed usage information.
# J1: Connect pin 2 and 3 for USB power.
# J2: Connect pin 2 and 3 for USB power.
# J2: Pin 7 is SCK
#   : Pin 8 is MOSI
#   : Pin 9 is MISO
#   : Pin 11 is RST
#   : Pin 6 is ground
# Use the -b flag to set the SPI clock rate eg -b 3750000 is the fastest I could get
# a 16MHz Atmega1280 to program reliably.  The 232H is conveniently 5V tolerant.
programmer
  id         = "UM232H";
  desc       = "FT232H based module from FTDI and Glyn.com.au";
  type       = "avrftdi";
  usbvid     = 0x0403;
# Note: This PID is reserved for generic 232H devices and
# should be programmed into the EEPROM
  usbpid     = 0x6014;
  usbdev     = "A";
  usbvendor  = "";
  usbproduct = "";
  usbsn      = "";
#ISP-signals
  sck    = 0;
  mosi   = 1;
  miso   = 2;
  reset  = 3;
;

如在运行烧写时出现在下面错误,也就是在一些avrdude.conf内没有支持UM232H的原因之一.

1	avrdude: Error: no libftdi or libusb support. Install libftdi1/libusb-1.0 or libftdi/libusb and run configure/make again.

这里比较简单解决办法是,使用系统的/usr/bin/avrdude来替换.arduino15/packages/arduino/tools/avrdude/6.3.0-arduino17/bin/avrdude

为什么Arduino IDE为会调用包内的工具(avrdude),因为它的路径定义如下:

~$ grep "avrdude.path" ~/.arduino15/packages/arduino/hardware/avr/1.8.3/platform.txt
tools.avrdude.path={runtime.tools.avrdude.path}

~$ grep "avrdude.path" ~/.arduino15/packages/ATTinyCore/hardware/avr/1.4.1/platform.txt
tools.avrdude.path={runtime.tools.avrdude.path}

最后,新增其它的种类的烧写器也是类似,如:FT2232HL等.这种方式,就是可以使用Arduino IDE生态内的软件库,所带来快速开发与测试硬件的优势.也可使用Makefile的方式使用avrdude来烧写.

添加`2232HL`

打开/etc/avrdude.conf文件发现，里面默认定义了FT2232H，FT4232H的配置如下：

~$ cat /etc/avrdude.conf
[...]
programmer
    id         = "2232HIO";
    desc       = "FT2232H based generic programmer";
    type       = "avrftdi";
    connection_type = usb;
    usbvid     = 0x0403;
  # Note: This PID is reserved for generic H devices and
  # should be programmed into the EEPROM
  #  usbpid     = 0x8A48;
    usbpid     = 0x6010;
    usbdev     = "A";
    usbvendor  = "";
    usbproduct = "";
    usbsn      = "";
  #ISP-signals
    reset  = 3;
    sck    = 0;
    mosi   = 1;
    miso   = 2;
    buff   = ~4;
  #LED SIGNALs
    errled = ~ 11;
    rdyled = ~ 14;
    pgmled = ~ 13;
    vfyled = ~ 12;
  ;

  #The FT4232H can be treated as FT2232H, but it has a different USB
  #device ID of 0x6011.
  programmer parent "avrftdi"
    id         = "4232h";
    desc       = "FT4232H based generic programmer";
    usbpid     = 0x6011;
  ;
[...]

如上所示,在系统级的avrdude已经支持FT2232H,这里只需要硬件库里programmers.txt添加一个对应到FT2232H的项就可以了。但是一般在硬件库里，还有一份avrdude.conf,按顺序会先是检查硬件库里的相关配置。这里还是以ATTinyCore的硬件库为例：

~$ tail -n 10 ~/.arduino15/packages/ATTinyCore/hardware/avr/1.5.2/programmers.txt


ft2232h.name=2232HIO as ISP
ft2232h.communication=serial
ft2232h.protocol=avrftdi
ft2232h.speed=19200
ft2232h.program.protocol=avrftdi
ft2232h.program.speed=19200
ft2232h.program.tool=avrdude
ft2232h.program.extra_params=-P{serial.port} -b{program.speed}

ft2232h连接attiny85

 FT2232H              ATTiny85

ADBUS0   <------>   SCK    PB2
ADBUS1   <------>   MOSI   PB0
ADBUS2   <------>   MISO   PB1
ADBUS3   <------>   Reset  PB5
  GND    <------>   GND
  +5V    <------>   +5V  (VIN)

`AVRDude`烧写

前面是在ATTiny85Flash里烧写一个bootloader开启SELFPRGEN Self-Programming Enable与SPIEN Enable Serial Program and Data Downloading的功能,优点就是让它能通过USB(D-: PB3/AD3,D+: PB4/AD2)可以烧写程序,可以简单与Arduino IDE集成使用,不需要外接烧写器.缺点就是要消耗2kb的存储空间,但是Attiny85就只有8kb的Flash空间.

下面就是通过使用UM232H像烧写bootloader的方法去开发编程,可以完全使用8kb的空间.下面是一个简单blink示例.

~ blink$ cat main.c
// main.c
//
// A simple blinky program for ATtiny85
// Connect red LED at pin 2 (PB1)
//
// electronut.in

#include <avr/io.h>
#include <util/delay.h>

int main (void)
{
  // set PB1 to be output
	DDRB = 0b00000010;
  while (1) {

    // flash# 1:
    // set PB1 high
    PORTB = 0b00000010;
    _delay_ms(20);
    // set PB1 low
    PORTB = 0b00000000;
    _delay_ms(20);

    // flash# 2:
    // set PB1 high
    PORTB = 0b00000010;
    _delay_ms(200);
    // set PB1 low
    PORTB = 0b00000000;
    _delay_ms(200);
  }

  return 1;
}

Makefile

# Makefile for programming the ATtiny85
# modified the one generated by CrossPack

DEVICE      = attiny85
CLOCK      = 8000000
PROGRAMMER = -c UM232H
OBJECTS    = main.o
# for ATTiny85
# see http://www.engbedded.com/fusecalc/
FUSES       = -U lfuse:w:0x62:m -U hfuse:w:0xdf:m -U efuse:w:0xff:m

# Tune the lines below only if you know what you are doing:
AVRDUDE = avrdude $(PROGRAMMER) -p $(DEVICE)
COMPILE = avr-gcc -Wall -Os -DF_CPU=$(CLOCK) -mmcu=$(DEVICE)

# symbolic targets:
all:	main.hex

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

.S.o:
	$(COMPILE) -x assembler-with-cpp -c $< -o $@

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

flash:	all
	$(AVRDUDE) -U flash:w:main.hex:i

fuse:
	$(AVRDUDE) $(FUSES)

# Xcode uses the Makefile targets "", "clean" and "install"
install: flash fuse

# if you use a bootloader, change the command below appropriately:
load: all
	bootloadHID main.hex

clean:
	rm -f main.hex main.elf $(OBJECTS)

# file targets:
main.elf: $(OBJECTS)
	$(COMPILE) -o main.elf $(OBJECTS)

main.hex: main.elf
	rm -f main.hex
	avr-objcopy -j .text -j .data -O ihex main.elf main.hex
	avr-size --format=avr --mcu=$(DEVICE) main.elf
# If you have an EEPROM section, you must also create a hex file for the
# EEPROM and add it to the "flash" target.

# Targets for code debugging and analysis:
disasm:	main.elf
	avr-objdump -d main.elf

cpp:
	$(COMPILE) -E main.c

接线按照上面方法,因为这里是没有用使用bootloader,直接在blink目录下运行make flash就通过使用avrdude烧写到flash中.

也可以单独使用下面命令烧写.

1	~$ avrdude -C /etc/avrdude.conf -c UM232H -P /dev/ttyUSB1 -b 19200 -p attiny85 -U flash:w:main.hex:i

高压编程恢复`熔丝位(fuse)`锁死

Links
恢复熔丝位(fuse)还是有一点麻烦,按照博文High Voltage programming/Unbricking for Attiny指导,需要有一个Arduino设备,或者说至少要一个有6个IO口的单片机.还需要6个1k的电阻,一个(npn)的三极管,一个12V的电压源.如图：

读取熔丝位(fuse)

~$ avrdude -C /etc/avrdude.conf -c UM232H -P /dev/ttyUSB1 -b 19200 -p attiny85  -U lfuse:r:-:i -v

avrdude: Version 6.3-20171130
         Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
         Copyright (c) 2007-2014 Joerg Wunsch

         System wide configuration file is "/etc/avrdude.conf"
         User configuration file is "/home/michael/.avrduderc"
         User configuration file does not exist or is not a regular file, skipping

         Using Port                    : /dev/ttyUSB1
         Using Programmer              : UM232H
         Overriding Baud Rate          : 19200
         AVR Part                      : ATtiny85
         Chip Erase delay              : 4500 us
         PAGEL                         : P00
         BS2                           : P00
         RESET disposition             : possible i/o
         RETRY pulse                   : SCK
         serial program mode           : yes
         parallel program mode         : yes
         Timeout                       : 200
         StabDelay                     : 100
         CmdexeDelay                   : 25
         SyncLoops                     : 32
         ByteDelay                     : 0
         PollIndex                     : 3
         PollValue                     : 0x53
         Memory Detail                 :

                                  Block Poll               Page                       Polled
           Memory Type Mode Delay Size  Indx Paged  Size   Size #Pages MinW  MaxW   ReadBack
           ----------- ---- ----- ----- ---- ------ ------ ---- ------ ----- ----- ---------
           eeprom        65     6     4    0 no        512    4      0  4000  4500 0xff 0xff
           flash         65     6    32    0 yes      8192   64    128  4500  4500 0xff 0xff
           signature      0     0     0    0 no          3    0      0     0     0 0x00 0x00
           lock           0     0     0    0 no          1    0      0  9000  9000 0x00 0x00
           lfuse          0     0     0    0 no          1    0      0  9000  9000 0x00 0x00
           hfuse          0     0     0    0 no          1    0      0  9000  9000 0x00 0x00
           efuse          0     0     0    0 no          1    0      0  9000  9000 0x00 0x00
           calibration    0     0     0    0 no          1    0      0     0     0 0x00 0x00

         Programmer Type : avrftdi
         Description     : FT232H based module from FTDI and Glyn.com.au

avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.01s

avrdude: Device signature = 0x1e930b (probably t85)
avrdude: safemode: lfuse reads as 62
avrdude: safemode: hfuse reads as DF
avrdude: safemode: efuse reads as FE
avrdude: reading lfuse memory:

Reading | ################################################## | 100% 0.00s

avrdude: writing output file "<stdout>"
:01000000629D
:00000001FF

avrdude: safemode: lfuse reads as 62
avrdude: safemode: hfuse reads as DF
avrdude: safemode: efuse reads as FE
avrdude: safemode: Fuses OK (E:FE, H:DF, L:62)

avrdude done.  Thank you.

内存爆掉的问题,定义了一个1024的数组.

avr-size --format=avr --mcu=attiny85 main.elf
AVR Memory Usage
----------------
Device: attiny85

Program:    2454 bytes (30.0% Full)
(.text + .data + .bootloader)

Data:       1043 bytes (203.7% Full)
(.data + .bss + .noinit)

`ATTiny85/Atmega328p`时钟计数器相关

Links:

8位定时器(timer0)

先确认手上的ATtiny85的时钟频是否在运行在8MHz,可以通过读取它的fuse位来判定,这里使用的是-U lfuse:w:0xe2:m -U hfuse:w:0xdf:m -U efuse:w:0xff:m.这里测试用的fuse配置如图

ATTiny85默认时钟频率是8MHz,表示它可以每秒进行8000000次周期开关(高电平,低电平),每一个周期的时间段(time period)是1/8000000s也就是0.000000125s，也就是125ns,而一个16位的定时器(0-65535),在每个时钟周期加一，从0到上65536上溢只需要8.192ms,8位的定时器只需要0.032ms就上溢了。如果我们需要更长时间的定时间隔，那么就需要预分频器对时钟进行分频处理,根据芯片手册14.9.2 TCCR0B - Timer/Counter Control Register B描述，通过设置TCCRB0B寄存器的Bit2:0位，可以进如下预分频

CS02	CS01	CS00	Description
0	0	0	No clock source (Timer/Counter stopped)
0	0	1	clk I/O /(no prescaling)
0	1	0	clk I/O /8 (from prescaler)
0	1	1	clk I/O /64 (from prescaler)
1	0	0	clk I/O /256 (from prescaler)
1	0	1	clk I/O /1024 (from prescaler)
1	1	0	External clock source on T0 pin. Clock on falling edge.
1	1	1	External clock source on T0 pin. Clock on rising edge.

下面这个程序使用8位定时器来延时1秒，每秒翻转一次状态的blink示例。ATtiny85默认是8MHz,每个周期是1/8MHz = 0.125us = 125ns,按1024预频后得到7812.5Hz。也就是说，定时器每隔7812.5Hz加1，换算成时间是1/7812.5 = 0.000128s,8位定时器只能计数到0.000128s * 255 = 0.032639999999999995。

设定T/C0的工作状态为CTC模式，开启T/C0输出比较匹配中断使能位，使用OCR0A比较寄存器保存数值做比较。这里设置OCR0A=250,当TCNT0的值达到250后就会产生比较中断(250 < 255>).中断32次后，也是就约等于1秒钟，并且对PB1的状态进行翻转。

~$ cat timer0.c
#include <avr/io.h>
#include <avr/interrupt.h>

int intr_count = 0;
void setupTimer0() {
  cli();
  // Clear registers
  TCCR0A = 0;
  TCCR0B = 0;

  // 7812.5 Hz (8000000/((0+1)*1024))
  OCR0A = 250; //  0.000128s * 250 = 32ms
  // CTC 比较匹配时清零定时器模式
  TCCR0A |= (1 << WGM01);
  // Prescaler 1024
  TCCR0B |= (1 << CS02) | (1 << CS00);
  // Output Compare Match A Interrupt Enable
  TIMSK |= (1 << OCIE0A);
  sei(); //enabling global interrupt, or  SREG |= 0x80
}

ISR(TIMER0_COMPA_vect) {
  if(intr_count == 31)
  {
    intr_count = 0;
    PORTB^=(1<<PB1); //toggling the LED
  } else intr_count++;
}

int main ()
{
  DDRB = 0b00000010; // enable PB1
  setupTimer0();
  while(1)
  {}
}

ATtiny85的timer1也是一个8bit定时器,但是支持最大14-bit(MAX=16384)的预分频,下面是一个测试。设置比较寄存器的值为248，中断两次逻辑采样得到1.006s的方波。1/488.28125 = 0.002048s,也等于0.000000125s * 16384 = 0.002048s.

~$ cat timer1.c

int intr_count = 0;
void setupTimer1() {
  noInterrupts();
  // Clear registers
  TCNT1 = 0;
  TCCR1 = 0;

  // 488.28125 Hz (8000000/((0+1)*16384))
  OCR1C = 248;
  // interrupt COMPA
  OCR1A = OCR1C;
  // CTC
  TCCR1 |= (1 << CTC1);
  // Prescaler 16384
  TCCR1 |= (1 << CS13) | (1 << CS12) | (1 << CS11) | (1 << CS10);
  // Output Compare Match A Interrupt Enable
  TIMSK |= (1 << OCIE1A);
  sei();
}

int main ()
{
  DDRB = 0b00000010; // enable PB1
  setupTimer0();
  while(1)
  {}
}

ISR(TIMER0_COMPA_vect) {
  if(intr_count == 1)
  {
    intr_count = 0;
    PORTB^=(1<<PB1); //toggling the LED
  } else intr_count++;
}

16位定时器(timer1)

下面这个程序使用ATmega328p的16位定时器1来延时1秒，ATmega328p默认是16MHz,每个周期是1/16MHz = 0.0625us,把它1024的预分频后得到15625Hz,这里的设置与上面ATtiny85雷同,只是这里使用的是16位定时器(0-65535), 下面把比较器设置成15640通过逻辑采样得到一个1s的方波,而使用15625得到是0.9993s的方波。

~$ cat timer1.ino
// AVR Timer CTC Interrupts Calculator
// v. 8
// http://www.arduinoslovakia.eu/application/timer-calculator
// Microcontroller: ATmega328P
// Created: 2022-04-27T14:02:45.452Z

#define ledPin 13

void setupTimer1() {
  noInterrupts();
  // Clear registers
  TCCR1A = 0;
  TCCR1B = 0;
  TCNT1 = 0;

  // 15625 Hz (16000000/((0+1)*1024))
  OCR1A = 15640;
  // CTC
  TCCR1B |= (1 << WGM12);
  // Prescaler 1024
  TCCR1B |= (1 << CS12) | (1 << CS10);
  // Output Compare Match A Interrupt Enable
  TIMSK1 |= (1 << OCIE1A);
  interrupts();
}

void setup() {
  pinMode(ledPin, OUTPUT);
  setupTimer1();
}

void loop() {
}

ISR(TIMER1_COMPA_vect) {
  digitalWrite(ledPin, digitalRead(ledPin) ^ 1);
}

ATmega8-16PU

Link:

Programming ATmega8 Using Arduino IDE
ATMEGA8-16PU
AVR Tutorial - Getting Started: Blinking an LED
下面是使用一块ATmega8-16PU与一块面包板，搭的简单测试

添加`Arduino IDE`支持

open File menu, click on Preferences.Now in Additional Boards Manger URLs, enter the following URL:https://mcudude.github.io/MiniCore/package_MCUdude_MiniCore_index.json
Go to Tools menu and then select Board > Boards Manager,In Boards Manager window, search for MiniCore and then install the latest version.

`ATmega8-16pu`连接`UM232H`

 UM232H              ATmega8-16pu       arduino pin out
AD0 (CK)  <------->  Pin19 PB5 (SCK)   digital pin 13
AD1 (DO)  <------->  Pin17 PB3 (MOSI)  digital pin 11
AD2 (DI)  <------->  Pin18 PB4 (MISO)  digital pin 12
AD3 (CS)  <------->  Pin1  PC6 (RESET)
  GND     <------->  Pin8  GND
  +5v     <------->  Pin7  VCC

读写`fuse`

下面是读取它的fuse设置。

~$ avrdude -c UM232H -P /dev/ttyUSB1 -b 19200 -p m8  -U lfuse:r:-:i -v

avrdude: Version 6.3-20171130
         Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
         Copyright (c) 2007-2014 Joerg Wunsch

         System wide configuration file is "/etc/avrdude.conf"
         User configuration file is "/home/michael/.avrduderc"
         User configuration file does not exist or is not a regular file, skipping

         Using Port                    : /dev/ttyUSB1
         Using Programmer              : UM232H
         Overriding Baud Rate          : 19200
         AVR Part                      : ATmega8
         Chip Erase delay              : 10000 us
         PAGEL                         : PD7
         BS2                           : PC2
         RESET disposition             : dedicated
         RETRY pulse                   : SCK
         serial program mode           : yes
         parallel program mode         : yes
         Timeout                       : 200
         StabDelay                     : 100
         CmdexeDelay                   : 25
         SyncLoops                     : 32
         ByteDelay                     : 0
         PollIndex                     : 3
         PollValue                     : 0x53
         Memory Detail                 :

                                  Block Poll               Page                       Polled
           Memory Type Mode Delay Size  Indx Paged  Size   Size #Pages MinW  MaxW   ReadBack
           ----------- ---- ----- ----- ---- ------ ------ ---- ------ ----- ----- ---------
           eeprom         4    20   128    0 no        512    4      0  9000  9000 0xff 0xff
           flash         33    10    64    0 yes      8192   64    128  4500  4500 0xff 0x00
           lfuse          0     0     0    0 no          1    0      0  2000  2000 0x00 0x00
           hfuse          0     0     0    0 no          1    0      0  2000  2000 0x00 0x00
           lock           0     0     0    0 no          1    0      0  2000  2000 0x00 0x00
           calibration    0     0     0    0 no          4    0      0     0     0 0x00 0x00
           signature      0     0     0    0 no          3    0      0     0     0 0x00 0x00

         Programmer Type : avrftdi
         Description     : FT232H based module from FTDI and Glyn.com.au

avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.01s

avrdude: Device signature = 0x1e9307 (probably m8)
avrdude: safemode: lfuse reads as 62
avrdude: safemode: hfuse reads as DF
avrdude: reading lfuse memory:

Reading | ################################################## | 100% 0.00s

avrdude: writing output file "<stdout>"
:01000000629D
:00000001FF

avrdude: safemode: lfuse reads as 62
avrdude: safemode: hfuse reads as DF
avrdude: safemode: Fuses OK (E:FF, H:DF, L:62)

avrdude done.  Thank you.

写入fuse的配置，这里是通过AVR® Fuse Calculator配置计算出来的。

~$avrdude -c UM232H -P /dev/ttyUSB1 -b 19200 -p m8   -U lfuse:w:0xd4:m -U hfuse:w:0xc9:m

avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.01s

avrdude: Device signature = 0x1e9307 (probably m8)
avrdude: reading input file "0xd4"
avrdude: writing lfuse (1 bytes):

Writing | ################################################## | 100% 0.01s

avrdude: 1 bytes of lfuse written
avrdude: verifying lfuse memory against 0xd4:
avrdude: load data lfuse data from input file 0xd4:
avrdude: input file 0xd4 contains 1 bytes
avrdude: reading on-chip lfuse data:

Reading | ################################################## | 100% 0.00s

avrdude: verifying ...
avrdude: 1 bytes of lfuse verified
avrdude: reading input file "0xc9"
avrdude: writing hfuse (1 bytes):

Writing | ################################################## | 100% 0.00s

avrdude: 1 bytes of hfuse written
avrdude: verifying hfuse memory against 0xc9:
avrdude: load data hfuse data from input file 0xc9:
avrdude: input file 0xc9 contains 1 bytes
avrdude: reading on-chip hfuse data:

Reading | ################################################## | 100% 0.00s

avrdude: verifying ...
avrdude: 1 bytes of hfuse verified

avrdude: safemode: Fuses OK (E:FF, H:C9, L:D4)

avrdude done.  Thank you.

基于`Rust`语言开发测试

Links:
- Rust on a Digispark ATtiny85

Prerequistes

1	~$ sudo apt install binutils-avr avr-libc gcc-avr pkg-config avrdude libudev-dev

Install Micronucleus (Optional)

ft2232h Link to Lilytiny Attiny85

 FT2232H              ATTiny85

ADBUS0   <------>   SCK    PB2
ADBUS1   <------>   MOSI   PB0
ADBUS2   <------>   MISO   PB1
ADBUS3   <------>   Reset  PB5
  GND    <------>   GND
  +5V    <------>   VIN

Build and Flash firmware

1
2
3

~$ git clone https://github.com/micronucleus/micronucleus
~$ cd micronucleus
~$ make PROGRAMMER="-c UM232H -P /dev/ttyUSB0 -b 19200"  flash

Build micronucleus flash CLI tool

1
2
3

~$ sudo apt-get install libusb-dev
~$ cd micronucleus/commandline
~$ make && cp micronucleus /usr/bin

Connected to board USB

~$ lsusb -v -s 001:030

Bus 001 Device 030: ID 16d0:0753 MCS Digistump DigiSpark
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               1.10
  bDeviceClass          255 Vendor Specific Class
  bDeviceSubClass         0
  bDeviceProtocol         0
  bMaxPacketSize0         8
  idVendor           0x16d0 MCS
  idProduct          0x0753 Digistump DigiSpark
  bcdDevice            2.06
  iManufacturer           0
  iProduct                0
  iSerial                 0
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength       0x0012
    bNumInterfaces          1
    bConfigurationValue     1
    iConfiguration          0
    bmAttributes         0x80
      (Bus Powered)
    MaxPower              100mA
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           0
      bInterfaceClass         0
      bInterfaceSubClass      0
      bInterfaceProtocol      0
      iInterface              0
Device Status:     0xffff
  Self Powered
  Remote Wakeup Enabled
  Test Mode
  Debug Mode

Install Rust env

1	~$ cargo +stable install ravedude

Build blink project

~$ git clone https://github.com/Rahix/avr-hal
~$ cd avr-hal/example/trinket
~$ cargo build
~$ avr-objcopy --output-target=ihex ../../target/avr-attiny85/debug/trinket-simple-pwm.elf ../../target/avr-attiny85/debug/trinket-simple-pwm.hex
~$ micronucleus --timeout 60 --run --no-ansi ../../target/avr-attiny85/debug/trinket-simple-pwm.hex

Build release `Minimzing Rust Binary Size` test

added following lines into the Cargo.toml

[profile.release]
strip = true
opt-level = "z"  # Optimize for size.
lto = true
panic = "abort"
debug = false

Build Release

~$ RUSTFLAGS="-Zlocation-detail=none" cargo build --release
warning: profiles for the non root package will be ignored, specify profiles at the workspace root:
package:   /fullpath//github/AVR/avr-hal/examples/trinket/Cargo.toml
workspace: /fullpath//github/AVR/avr-hal/Cargo.toml
   Compiling compiler_builtins v0.1.98
   Compiling core v0.0.0 (/home/michael/.rustup/toolchains/nightly-2023-08-08-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core)
   Compiling proc-macro2 v1.0.69
   Compiling unicode-ident v1.0.12
   Compiling syn v1.0.109
   Compiling proc-macro-hack v0.5.20+deprecated
   Compiling rustversion v1.0.14
   Compiling paste v1.0.14
   Compiling quote v1.0.33
   Compiling avr-hal-generic v0.1.0 (/fullpath//github/AVR/avr-hal/avr-hal-generic)
   Compiling avr-device-macros v0.5.2
   Compiling ufmt-macros v0.1.1 (https://github.com/Rahix/ufmt.git?rev=12225dc1678e42fecb0e8635bf80f501e24817d9#12225dc1)
   Compiling rustc-std-workspace-core v1.99.0 (/home/michael/.rustup/toolchains/nightly-2023-08-08-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/rustc-std-workspace-core)
   Compiling nb v1.1.0
   Compiling ufmt-write v0.1.0 (https://github.com/Rahix/ufmt.git?rev=12225dc1678e42fecb0e8635bf80f501e24817d9#12225dc1)
   Compiling bare-metal v1.0.0
   Compiling vcell v0.1.3
   Compiling cfg-if v1.0.0
   Compiling void v1.0.2
   Compiling cfg-if v0.1.10
   Compiling embedded-storage v0.2.0
   Compiling panic-halt v0.2.0
   Compiling ufmt v0.1.0 (https://github.com/Rahix/ufmt.git?rev=12225dc1678e42fecb0e8635bf80f501e24817d9#12225dc1)
   Compiling avr-device v0.5.2
   Compiling nb v0.1.3
   Compiling embedded-hal v0.2.7
   Compiling attiny-hal v0.1.0 (/fullpath//github/AVR/avr-hal/mcu/attiny-hal)
   Compiling arduino-hal v0.1.0 (/fullpath//github/AVR/avr-hal/arduino-hal)
   Compiling trinket-examples v0.0.0 (/fullpath//github/AVR/avr-hal/examples/trinket)
WARN rustc_codegen_ssa::back::link Linker does not support -no-pie command line option. Retrying without.
WARN rustc_codegen_ssa::back::link Linker does not support -no-pie command line option. Retrying without.
    Finished release [optimized + debuginfo] target(s) in 6.60s

驱动`NRF24l01`

Links：

nrf24l01+ control with 3 ATtiny85 pins
[nRF24l01 control with 2 MCU pins using time-division duplexed SPI](https://nerdralph.blogspot.com/2015/05/ nrf24l01-control-with-2-mcu-pins-using.html)
Fastest AVR software SPI in the West
nerdralph
ATtiny84/85 SPI Interface Pin Reuse
[ATtiny85 SPI protocol – Master and Slave mode tutorial](https://www.gadgetronicx.com/ attiny85-spi-protocol-master-slave-mode-tutorial/)
NRF24l01正常工作的要寄存器值如下：

CONFIG:    0b
EN_AA:     3e
EN_RXADDR: 01
SETUP_AW:  02
SETUP_RETR:30
RF_CH:     02
RF_SETUP:  05
STATUS:    0e
OBS_TX:    00
TX_ADDR:   71917d6b
CD:        00
RX_PW_P0:  20
RX_PW_P1:  00
RX_PW_P2:  00
RX_PW_P3:  00
RX_PW_P4:  00
RX_PW_P5:  00
FIFO_STAT: 11
DYNPD:     00
FEATURE:   05

驱动`SSD1306`

调试

GDB

逻辑分析仪的问题

Fx2lafw
PulseView
Use a raspberry pi pico (rp2040) as a logic
Raspberry Pi PinOut
连接逻辑分析仪时,不知为何,有时会出现干扰,让程序跑飞,而断开后运行的很正常.

字符相关

AVR-GCC汇编相关

GCC asm Statement

Let’s start with a simple example of reading a value from port D:
1
asm("in %0, %1" : "=r" (value) : "I" (_SFR_IO_ADDR(PORTD)) );
Eachasmstatement is devided by colons into (up to) four parts:
1. The assembler instructions, defined as a single string constant: "in %0, %1"
2. A list of output operands, separated by commas. Our example uses just one: "=r" (value)
3. A comma separated list of input operands. Again our example uses one operand only:
  "I" (_SFR_IO_ADDR(PORTD))
4. Clobbered registers, left empty in our example.
You can write assembler instructions in much the same way as you would write assembler programs. However, registers andconstants are used in a different way if they refer to expressions of your C program. The connection between registersand C operands is specified in the second and third part of the asm instruction, the list of input and output operands,respectively. The general form is

1	asm(code : output operand list : input operand list [: clobber list]);

In the code section, operands are referenced by a percent sign followed by a single digit. %0 refers to the first %1 tothe second operand and so forth. From the above example:

1 2	%0 refers to "=r" (value) and %1 refers to "I" (_SFR_IO_ADDR(PORTD)).

Input and Output Operands

Each input and output operand is described by a constraint string followed by a C expression in parantheses. AVR-GCC 3.3knows the following constraint characters:
Note
- The most up-to-date and detailed information on contraints for the avr can be found in the gcc manual.
- The x register is r27:r26, the y register is r29:r28, and the z register is r31:r30

Constraint	Used for	Range
a	Simple upper registers	r16 to r23
b	Base pointer registers pairs	y, z
d	Upper register	r16 to r31
e	Pointer register pairs	x, y, z
q	Stack pointer register	SPH:SPL
r	Any register	r0 to r31
t	Temporary register	r0
w	Special upper register pairs	r24, r26, r28, r30
x	Pointer register pair X	x (r27:r26)
y	Pointer register pair Y	y (r29:r28)
z	Pointer register pair Z	z (r31:r30)
G	Floating point constant	0.0
I	6-bit positive integer constant	0 to 63
J	6-bit negative integer constant	-63 to 0
K	Integer constant	2
L	Integer constant	0
l	Lower registers	r0 to r15
M	8-bit integer constant	0 to 255
N	Integer constant	-1
O	Integer constant	8, 16, 24
P	Integer constant	1
Q	(GCC >= 4.2.x) A memory address based on Y or Z pointer with displacementa.
R	(GCC >= 4.3.x) Integer constant.	-6 to 5

Mnemonic	Constraints	Mnemonic	Constraints
adc	r,r	add	r,r
adiw	w,I	and	r,r
andi	d,M	asr	r
bclr	I	bld	r,I
brbc	I,label	brbs	I,label
bset	I	bst	r,I
cbi	I,I	cbr	d,I
com	r	cp	r,r
cpc	r,r	cpi	d,M
cpse	r,r	dec	r
elpm	t,z	eor	r,r
in	r,I	inc	r
ld	r,e	ldd	r,b
ldi	d,M	lds	r,label
lpm	t,z	lsl	r
lsr	r	mov	r,r
movw	r,r	mul	r,r
neg	r	or	r,r
ori	d,M	out	I,r
pop	r	push	r
rol	r	ror	r
sbc	r,r	sbci	d,M
sbi	I,I	sbic	I,I
sbiw	w,I	sbr	d,M
sbrc	r,I	sbrs	r,I
ser	d	st	e,r
std	b,r	sts	label,r
sub	r,r	subi	d,M
swap	r

Constraint characters may be prepended by a single constraint modifier. Contraints without a modifier specify read-only operands. Modifiers are:
Modifier Specifies

1
2
3

= 	Write-only operand, usually used for all output operands.
+ 	Read-write operand
& 	Register should be used for output only

comment In assembler programming, the term clobbered registers is used to denote any registers whose value may beoverwritten during the course of executing an instruction or procedure.

谢谢支持

微信二维码:

Sunrise 博客

AVR单片机指南

ATmega32U4(Arduino pro micro)

ATmega328p (Arduino Pro mini with CH340)

`UART`通信的要点

ATtiny85(CJMCU)

Bootloader

系统控制与复位

使用`Arduino IDE`支持(ATTinyCore)

使用`Arduino`上传第一个程序(blink).

新增烧写器(UM232H为例)

添加`2232HL`

`AVRDude`烧写

高压编程恢复`熔丝位(fuse)`锁死

`ATTiny85/Atmega328p`时钟计数器相关

8位定时器(timer0)

16位定时器(timer1)

ATmega8-16PU

添加`Arduino IDE`支持

`ATmega8-16pu`连接`UM232H`

读写`fuse`

基于`Rust`语言开发测试

Prerequistes

Install Micronucleus (Optional)

Install Rust env

Build blink project

Build release `Minimzing Rust Binary Size` test

驱动`NRF24l01`

驱动`SSD1306`

调试

GDB

逻辑分析仪的问题

字符相关

AVR-GCC汇编相关

GCC asm Statement

Input and Output Operands

谢谢支持

ATmega32U4(Arduino pro micro)

ATmega328p (Arduino Pro mini with CH340)

UART通信的要点

ATtiny85(CJMCU)

Bootloader

系统控制与复位

使用Arduino IDE支持(ATTinyCore)

使用Arduino上传第一个程序(blink).

新增烧写器(UM232H为例)

添加2232HL

AVRDude烧写

高压编程恢复熔丝位(fuse)锁死

ATTiny85/Atmega328p时钟计数器相关

8位定时器(timer0)

16位定时器(timer1)

ATmega8-16PU

添加Arduino IDE支持

ATmega8-16pu连接UM232H

读写fuse

基于Rust语言开发测试

Prerequistes

Install Micronucleus (Optional)

Install Rust env

Build blink project

Build release Minimzing Rust Binary Size test

驱动NRF24l01

驱动SSD1306

调试

GDB

逻辑分析仪的问题

字符相关

AVR-GCC汇编相关

GCC asm Statement

Input and Output Operands

谢谢支持

`UART`通信的要点

使用`Arduino IDE`支持(ATTinyCore)

使用`Arduino`上传第一个程序(blink).

添加`2232HL`

`AVRDude`烧写

高压编程恢复`熔丝位(fuse)`锁死

`ATTiny85/Atmega328p`时钟计数器相关

添加`Arduino IDE`支持

`ATmega8-16pu`连接`UM232H`

读写`fuse`

基于`Rust`语言开发测试

Build release `Minimzing Rust Binary Size` test

驱动`NRF24l01`

驱动`SSD1306`