my board ;my think

    

Interfacing microcontrollers to external devices

在microcontroller(MCU)中,來連接外部設備(device)時,一般的MCU可以直接連接TTL level的(eg. display,sound,motor,relay..)而對於其它(CMOS)的準備也可以接上IC來驅動(MX232)。但最主要的並不是其voltage(電壓)而是其電流(current)。(其MCU的驅動單位,功率 p=vi)

而在不同品牌MCU、不同類型(8x51,AVR,PCI及ARM)中，甚至不同port (pin)都有不同的驅動能力。

問題：

若在你需要連接10個LED,且每個都要20mA. 則你需要200mA.

A.

准雙向I/O埠/弱上拉(標
準8051輸出模式)、強推挽輸出/強上拉、僅為輸入(高阻)
或開漏輸出功能

A1.定其為標準的輸入/出 腳位

加上bjt amplifying transistor

其中R3為為限流電阻，其計算方法為粗約計算

設 diode requires Id=20mA, transistor Ic=100mA, VDD=5V.

R3=5/0.02=250K . 而R1及R2為voltage divider.

A2.

使用Darlington array driver(ULN2002)來代替個別的transistor,

每個腳位可提供100mA的驅動能力。

 

B.情況二,外接功率高的裝置(light bulb,110v)

B1.以relay 取代diode.

這時,你不能將relay直接接到MCU上，因為其relay switch時會damage port ping

It is important to add VD1 backward diode which protects transistor high voltage ‘spikes’ produced when the relay coil is switching

 

輸入時，

1.

有些MCU有內建其R(pull register),即只需接上switch即可。

2.

Data Types & Data Pointer

一直以來,我總是看過就算了
這些基本的項目.像是Data pointer,Data type之類
但...我每次都會遺忘.故還是做些整理吧
--------------------------------------------------------------- 

8051對對VGA控制(AL128

1.目的
2.要求
AL128
一,要求
1.模擬於其demo board的操作
2.移值到不同平台

二,觀察
觀察元件有1.al128 ,2.eeprom, 3.button
一啓動電源後,其動作讀取eeprom中的add 0,1,2的狀態後,
再依其add 1,2的內容之後,向al128寫入對應的資料.
而其四個按鈕來控制其對於vga-in,對s-vido output.
-----------------------------
AL128的操作,共有四個按鈕分別為:
1.pal
2.ntsc
3.VGA-IN
4.EGA-IN
再將此四個按鈕做組合而成的動作,即為al128 demo board動作
因為其VGA-in部份有再分為二種狀態,故vga-in改成:

1.pal
2.ntsc
3.VGA-IN1(vga-in2)
4.EGA-IN
-------------------------------
將其pal,ntsc,vga-in,ega-in分別來代表著bit 0~3
來進行對比,
ps.附件.1
-------------------------------
------------------------------
則

VGA-IN1 VGA-IN2 EGA-IN
| | |
--------------------------------- ---
|
NTSC
|
---------------------------------
| | |
VGA-IN1 VGA-IN2 EGA-IN
------------------------------------------
VGA-IN1 VGA-IN2 EGA-IN
| | |
--------------------------------- ---
|
PAL
|
---------------------------------
| | |
VGA-IN1 VGA-IN2 EGA-IN
圖.1
ps.
1.先假設其最初的狀態pal-ega-in
2.再由此出發
3.比如按下vga-in1,則變為pal-vga-in1
(ntsc ,則....ega-in-ntsc
-----------------------------------------
-----------------------------------------

PAL_EGA[]={0x01,0x02,0x03,0x18,0x02,0x78,0x50,0x00,0x21,0xF8,0x23,0x32,
0x22,0xFD,0x24,0xB7,0x25,0xB7,0x26,0x1F,0x27,0x40,0x28,0xA1,
0x33,0x02,0x73,0x00,0x40,0x00,0x53,0x00,0x71,0x1B,0x72,0x1B,
0x51,0xF9,0x52,0xF1,0xFF,0xFF};
PAL2_VGA[]={0x01,0x04,0x03,0x18,0x20,0x00,0x02,0x78,0x50,0x00,0x21,0x06,
0x22,0xFD,0x23,0xB2,0x24,0xCE,0x25,0xC8,0x26,0x1F,0x27,0x80,
0x28,0xBF,0x33,0x01,0x73,0x00,0x40,0x00,0x53,0x00,0x71,0x27,
0x72,0x24,0x51,0x06,0x52,0x07,0xFF,0xFF};
PAL1_VGA[]={0x01,0x03,0x03,0x18,0x20,0x00,0x02,0x78,0x50,0x00,0x21,0x02,
0x22,0x02,0x23,0xB2,0x24,0xBE,0x25,0xBC,0x26,0x1F,0x27,0x80,
0x28,0xBB,0x33,0x01,0x73,0x00,0x40,0x00,0x53,0x00,0x71,0x1F,
0x72,0x1E,0x51,0x00,0x52,0xF2,0xFF,0xFF};
-----------------------------
EGA_PAL[]={0x02,0x01,0x03,0x18,0x02,0x78,0x50,0x00,0x21,0xF8,0x23,0x32,
0x22,0xFD,0x24,0xB7,0x25,0xB7,0x26,0x1F,0x27,0x40,0x28,0xA1,
0x33,0x02,0x73,0x00,0x40,0x00,0x53,0x00,0x71,0x1B,0x72,0x1B,
0x51,0xF9,0x52,0xF1,0xFF,0xFF};
VGA2_PAL[]={0x02,0x01,0x03,0x18,0x20,0x00,0x02,0x78,0x50,0x00,0x21,0x06,
0x22,0xFD,0x23,0xB2,0x24,0xCE,0x25,0xC8,0x26,0x1F,0x27,0x80,
0x28,0xBF,0x33,0x01,0x73,0x00,0x40,0x00,0x53,0x00,0x71,0x27,
0x72,0x24,0x51,0x06,0x52,0x07,0xFF,0xFF};
VGA1_PAL[]={0x02,0x01,0x03,0x18,0x20,0x00,0x02,0x78,0x50,0x00,0x21,0x02,
0x22,0x02,0x23,0xB2,0x24,0xBE,0x25,0xBC,0x26,0x1F,0x27,0x80,
0x28,0xBB,0x33,0x01,0x73,0x00,0x40,0x00,0x53,0x00,0x71,0x1F,
0x72,0x1E,0x51,0x00,0x52,0xF2,0xFF,0xFF};

//-----------------------------------------
NTSC_EGA[]={0x01,0x02,0x03,0x18,0x02,0x58,0x50,0x00,0x21,0xFF,0x23,0xB2,
0x22,0xFD,0x24,0xB7,0x25,0xB7,0x26,0x1F,0x27,0x80,0x28,0xB7,
0x33,0x02,0x73,0x00,0x40,0x00,0x53,0x00,0x71,0x1B,0x72,0x1B,
0x51,0xFB,0x52,0xFA,0xFF,0xFF};
NTSC2_VGA[]={0x01,0x04,0x03,0x18,0x20,0x00,0x02,0x58,0x50,0x00,0x21,0xFF,
0x22,0xFC,0x23,0xB0,0x24,0xCE,0x25,0xBC,0x26,0x1F,0x27,0x80,
0x28,0xB4,0x33,0x00,0x73,0x00,0x40,0x00,0x53,0x00,0x71,0x27,
0x72,0x1E,0x51,0x02,0x52,0xFA,0xFF,0xFF};
NTSC1_VGA[]={0x01,0x03,0x03,0x18,0x20,0x00,0x02,0x58,0x50,0x00,0x21,0xFF,
0x22,0x02,0x23,0xAD,0x24,0xBE,0x25,0xBC,0x26,0x1F,0x27,0x80,
0x28,0xB4,0x33,0x00,0x73,0x00,0x40,0x00,0x53,0x00,0x71,0x1F,
0x72,0x1E,0x51,0x02,0x52,0xFA,0xFF,0xFF};
//-----------------------------------------
EGA_NTSC[]={0x02,0x00,0x03,0x18,0x02,0x58,0x50,0x00,0x21,0xFF,0x23,0xB2,
0x22,0xFD,0x24,0xB7,0x25,0xB7,0x26,0x1F,0x27,0x80,0x28,0xB7,
0x33,0x02,0x73,0x00,0x40,0x00,0x53,0x00,0x71,0x1B,0x72,0x1B,
0x51,0xFB,0x52,0xFA,0xFF,0xFF};
VGA2_NTSC[]={0x02,0x00,0x03,0x18,0x20,0x00,0x02,0x58,0x50,0x00,0x21,0xFF,
0x22,0xFC,0x23,0xB0,0x24,0xCE,0x25,0xBC,0x26,0x1F,0x27,0x80,
0x28,0xB4,0x33,0x00,0x73,0x00,0x40,0x00,0x53,0x00,0x71,0x27,
0x72,0x1E,0x51,0x02,0x52,0xFA,0xFF,0xFF};
VGA1_NTSC[]={0x02,0x00,0x03,0x18,0x20,0x00,0x02,0x58,0x50,0x00,0x21,0xFF,
0x22,0x02,0x23,0xAD,0x24,0xBE,0x25,0xBC,0x26,0x1F,0x27,0x80,
0x28,0xB4,0x33,0x00,0x73,0x00,0x40,0x00,0x53,0x00,0x71,0x1F,
0x72,0x1E,0x51,0x02,0x52,0xFA,0xFF,0xFF};

以上分別代表著圖.1中的各種形狀下的所要寫入al128的資料
.偶數add為register number.;奇數則為資料
ex.
VGA1_NTSC[]={0x02,0x00,0x03,0x18,0x20,0x00,0x02,0x58,0x50,0x00,0x21,0xFF,
狀態為vga-in1-ntsc
向0x02 register number 寫入 00
向0x03 register number 寫入 18
向0x20 register number 寫入 00
............
..

------------------------------------------------------------------
三.實作

1.定義以一個exteral object 來記錄目前的狀態
2.讀取其eeprom中的add 01,02,來記錄
3.依其狀態來寫入,但第一筆 並沒 勿略
4.等侍使用者改變其記錄(在此是以button
5.依其狀態來寫入
6.回到步 4.

四,問題
1.對於J3並沒有使用到.它是用於RX,TX.可外接UART

2.因為改變其MCU的,目前是使用Winbound 系列.
若要求支援ISP的功能,則其電路需要改變

3..............................
為了方便於改變其相對應的設定值.
改由以code banking來存取?

基於8051.控制LCD mode(HD44780,KS0066,LC7981

目的:
為了Q板子,所撰寫的.
方便於檢查.故我依電路設計.並為了方便顯示其相關的資訊.
也為了建立一個自己的51 base-libary.

要求:
依其電路的設計,分別設計對LCD modle的控制.
分別memory map I/O 及 I/O map I/O.

ps:我有找一個PIC的網站.裡面有一個code lib
雖然網路上有很多關於51的資料,但都沒有
一個有整理出其資訊的地方
CCS:
General discussions related to using the CCS C compiler in your Microchip PICmicro MCU designs. Also any discussion related to embedded systems programming and design.

keil 對 Stack 的管理及local variable

最近...為了更一步了解其microc/os-II
回頭重看一下,關於相關的stack資訊
1.對於8051/52 memory map

base 8051,(架構,中斷

MC-51
特別
1.其變數的定義,無大小寫分別


8051的架構
微單晶--CPU,Memory,I/O
1.Memory 架構
除了無ROM型的8031及8032外,MCS-51之記憶体包括程式記憶体(ROM)與資料記憶体(RAM)
標準的8X51--4 kB ROM 及 128b RAM,而標準的8032 及8X52則為8K ROM ,256 b RAM