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2018年1月4日 星期四

使用 MOSFET 產生 PWM 電源

MCU 產生 25kHz PWM
因為 MCU 使用 3.3V, 一些 N通道MOSFET Vgs 甚至要 4V(IRFZ44N)
故用 2N7000(N通道) 推動 IRF5305(P通道)
示波器使用顏色
2N7000 Vg 為黃色
2N7000 Vd 為藍色
IRF5305 Vg 為紫色
IRF5305 Vd(out)為綠色

 一開始的設計R1=10K,並沒有使用R2電阻和223電容,Vd = Vg
加上R2(10K)電阻,因為分壓,使得 IRF5305 Vg 在工作範圍內擺動
加上223電容,加快輸出電壓上升
最後改R1=1K, R2=1K
即可加快輸出電壓的下降
缺最後一張圖


用單節18650產生3.0V

18650 電壓範圍 3.6-4.2V
要產生3.3V, 只有找到 TPS63020, TPS63060, TPS63070

LM1117 要求 Vin - Vout = 1.2V
3.6V - 1.2V = 2.4V

使用 TL431
注意在 750 Ohm, 上有一個較高的電壓(12V)
這裡可不能接 18650
Vout = 2.5 * (1 + 4.7 / 22) = 3.0V
PN2222 的 Vb為 3.0V + 0.7V = 3.7V
Ib = (12 - 3.7) / 750 = 11mA (在TL431 的 Ika 1~100mA 範圍內)
PN2222 的最小 β 為 35
Iout(max) = 11 * 35 = 387mA



2017年12月18日 星期一

使用 Arduino Pro Micro 當成 Arduino ISP 燒錄程式到 Atmega328P-PU 之二

請參考 上一篇 和 From Arduino to a Microcontroller on a Breadboard

雖然他只有提供 breadboard-1-6-x.zip,並沒有 1.8.5 的版本,是可以用的
秘訣是 Arduino IDE 不要使用安裝檔,使用 Windows zip file for non admin install
解開後取出 boards.txt 的內容加入 arduino-1.8.5 的 boards.txt
之前使用安裝檔,一直失敗

C:\Arduino\arduino-1.8.5-windows\arduino-1.8.5\hardware\arduino\avr\boards.txt
##############################################################
atmega328bb.name=ATmega328 on a breadboard (8 MHz internal clock)

atmega328bb.upload.protocol=arduino
atmega328bb.upload.maximum_size=30720
atmega328bb.upload.speed=57600

atmega328bb.bootloader.low_fuses=0xE2
atmega328bb.bootloader.high_fuses=0xDA
atmega328bb.bootloader.extended_fuses=0x05

atmega328bb.bootloader.file=atmega/ATmegaBOOT_168_atmega328_pro_8MHz.hex
atmega328bb.bootloader.unlock_bits=0x3F
atmega328bb.bootloader.lock_bits=0x0F

atmega328bb.build.mcu=atmega328p
atmega328bb.build.f_cpu=8000000L
atmega328bb.build.core=arduino:arduino
atmega328bb.build.variant=arduino:standard

##############################################################

參考 上一篇 ProMicro 到 Atmega328P 接線
先燒錄 Bootloader
Tools/Board:ATmega328 on a breadboard (8 MHz internal clock)
Tools/Port 選正確
Tools/Programmer/Arduino as ISP(Pro Micro)
Tools/Burn Bootloader

Bootloader 燒錄完成後,即可透過 RS-232 燒錄程式
USB轉RS-232(如 FT232RL)
FTDI  ->  Atmega328P
GND  ->  GND
CTS  ->  GND
VCC  ->  VCC
TXO  ->  2(RXD)
RXI  ->  3(TXD)
DTL  -> 1(RESET)

DTL 接 RESET 請參考 Arduino Pro Mini 電路
中間串接 0.1uF, Atmega328P 端的 Reset 要 Pull Up 10K

Tools/Board:ATmega328 on a breadboard (8 MHz internal clock)
Tools/Port 選RS-232 的 Port
Sketch/Upload (不要 Using Programmer)


2017年12月12日 星期二

使用 Arduino Pro Micro 當成 Arduino ISP 燒錄程式到 Atmega328P-PU

Arduino 1.8.5

File/Preferences/Additional Boards Manager URLs
https://raw.githubusercontent.com/sparkfun/Arduino_Boards/master/IDE_Board_Manager/package_sparkfun_index.json
Tools/Board/Boards Manager
安裝 SparkFun AVR Boards

修改 File/Examples/11.ArduinoISP/ArduinoISP
重新定義下列程式碼
#define RESET     10 // Use pin 10 to reset the target rather than SS
#define LED_HB    9
#define LED_ERR   8
#define LED_PMODE 7
#define PIN_SCK   15
#define PIN_MOSI  16
#define PIN_MISO  14
Tools/Board/SparkFun Pro Micro
Tools/Processor/Atmega32U4(5V,16MHz)
Tools/Port/(選正確 Com)
Sketch/Upload

主要接線
ProMicro  ->  Atmega328P-PU
VCC  ->  7(VCC)
GND  ->  8(GND)
VCC  ->  20(AVCC)
15(SCK)  ->  19(SCK)
14(MISO)  ->  18(MISO)
16(MOSI)  ->  17(MOSI)
10  ->  1(RESET)
File/Preferences/Additional Boards Manager URLs
https://github.com/Optiboot/optiboot/releases/download/v6.2/package_optiboot_optiboot-additional_index.json
Tools/Board/Boards Manager
安裝 Optiboot 6.2
若找不到, 並且有錯誤訊息
Error downloading https://github.com/Optiboot/optiboot/releases/download/v6.2/package_optiboot_optiboot-additional_index.json
下載並置於
C:\Arduino\arduino-1.8.5-windows\arduino-1.8.5\hardware/package_optiboot_optiboot-additional_index.json
更改 File/Preferences/Additional Boards Manager URLs 為
file://C:\Arduino\arduino-1.8.5-windows\arduino-1.8.5\hardware/package_optiboot_optiboot-additional_index.json

修改 C:\Arduino\arduino-1.8.5-windows\arduino-1.8.5\hardware\arduino\avr\programmers.txt
增加
arduinopromicro.name=Arduino as ISP(Pro Micro)
arduinopromicro.communication=serial
arduinopromicro.protocol=arduino
arduinopromicro.speed=19200
arduinopromicro.program.protocol=stk500v1
arduinopromicro.program.speed=19200
arduinopromicro.program.tool=avrdude
arduinopromicro.program.extra_params=-P{serial.port} -b{program.speed}

Tools/Programmer/Arduino as ISP(Pro Micro)
Tools/Processor/Atmega328p
Tools/Board/Optiboot on 28-pin cpus
Tools/CPU Speed/8MHz (int) (不使用外部震盪晶體)
Tools/Burn Bootloader (好像可以不用,但是時脈會錯誤)
燒錄程式需使用 Sketch/Upload Using Programmer, 不能使用 Upload

2017年11月24日 星期五

如何控制 DC-DC 輸出電壓

以下文章參考 Output voltage control of DC/DC converters

Vref 固定,且沒有電流
期望輸出電壓範圍 Vo1 ~ Vo2 (Vo1 < Vo2)
期望控制電壓範圍 Vc2 ~ Vc1(Vc1 < Vc2)
即是 Vc1 輸出 Vo1,Vc2 輸出 Vo2
以中間的節點來說 Ir1 + Ir2 + Ir3 = 0
Vref/R3 + (Vo1 - Vref)/R1 + (Vc1 - Vref)/R2 = 0
Vref/R3 + (Vo2 - Vref)/R1 + (Vc2 - Vref)/R2 = 0
因為 R3 固定,所以可以由聯立方程式解出 R1, R2

在上述範例中使用 LM2596(降壓),我使用 TL431(升壓)
須注意上方的電阻值,至少要能提供 TL431 1mA,才能正常工作

原先是想用 LM317-ADJ(降壓)
Vout = 1.25(1 + R2/R1)
請注意此時的 Vref = Vout - Vadj = 1.25
Vref/R1 + [Vc1 - (Vo1 - Vref)]/R2 + (Vo1 - Vref)/R3 = 0
Vref/R1 + [Vc2 - (Vo2 - Vref)]/R2 + (Vo2 - Vref)/R3 = 0
以上沒有試過,請小心

沒猜錯 XL6003(升壓) 也可以

2017年9月15日 星期五

Arduino pro mini

1. 製造 Arduino 燒錄器
接腳 FT232RL -> Arduino Pro Mini
DTR->DTR
RX->TXO
TX->RXI
VCC->VCC
CTX->GND
GND->GNC

選擇要當燒錄器的 Boards(Arduino Pro or Pro Mini) 和 Port
File/Examples/11.ArduinoISP/ArduinoISP
Sketch/Upload

2. 燒錄 bootloader
接腳 Arduino Pro Mini(Arduino 燒錄器)->Arduino Pro Mini
VCC->VCC
GND->GND
10->RST
11(MOSI)->11(MOSI)
12(MISO)->12(MISO)
13(SCK)->13(SCK)

File/Examples/01.Basics/Blank
選擇目標 Boards(Arduino Pro or Pro Mini)
Tools/Programmer/Arduino as ISP
Tools/Brun Bootloader
Sketch/Upload Using Programmer

2017年9月5日 星期二

SSL, RaspberryPi Server, Android Client

請參考 Android 與 Raspberry 證書 和 SSL 網路程式設計 的 Server 端
在此提供 Android 的 Client

package com.example.mark.sslclient;

import android.content.Context;
import android.content.res.AssetManager;
import android.util.Log;

import java.io.IOException;
import java.io.InputStream;
import java.security.KeyManagementException;
import java.security.KeyStore;
import java.security.KeyStoreException;
import java.security.NoSuchAlgorithmException;
import java.security.UnrecoverableKeyException;
import java.security.cert.Certificate;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;

import javax.net.ssl.KeyManagerFactory;
import javax.net.ssl.SSLContext;
import javax.net.ssl.TrustManager;
import javax.net.ssl.TrustManagerFactory;
import javax.net.ssl.X509TrustManager;

/** * Created by mark on 2017/9/1. */
public class SSLClient {
    static SSLContext ssl_ctx;

    public SSLClient(Context context) {
        try {
            Log.d("SSLClient", "SSLClient");

            //  Setup truststore            KeyStore trustStore = KeyStore.getInstance("BKS");
            InputStream trustStoreStream = context.getResources().openRawResource(R.raw.android);
            trustStore.load(trustStoreStream, "store1234".toCharArray());
            TrustManagerFactory trustManagerFactory = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
            trustManagerFactory.init(trustStore);
            Log.d("SSLClient", "Trust " + trustStore.size());
            Log.d("SSLClient", "trustManagerFactory " + trustManagerFactory.getTrustManagers().length);

            //  Setup keystore            KeyStore keyStore = KeyStore.getInstance("BKS");
            KeyManagerFactory keyManagerFactory = KeyManagerFactory.getInstance(KeyManagerFactory.getDefaultAlgorithm());
            InputStream keyStoreStream = context.getResources().openRawResource(R.raw.android);
            keyStore.load(keyStoreStream, "store1234".toCharArray());
            keyManagerFactory.init(keyStore, "key1234".toCharArray());
            Log.d("SSLClient", "Key " + keyStore.size());
            Log.d("SSLClient", "keyManagerFactory " + keyManagerFactory.getKeyManagers().length);

            // Setup the SSL context to use the truststore and keystore            ssl_ctx = SSLContext.getInstance("TLS");
            if (true) {
                ssl_ctx.init(keyManagerFactory.getKeyManagers(), trustManagerFactory.getTrustManagers(), null);
            } else {
                TrustManager tm = new X509TrustManager() {
                    public void checkClientTrusted(X509Certificate[] chain, String authTyhpe) throws CertificateException {
                    }
                    public void checkServerTrusted(X509Certificate[] chain, String authTyhpe) throws CertificateException {
                    }
                    public X509Certificate[] getAcceptedIssuers() {
                        return null;
                    }
                };
                ssl_ctx.init(null, new TrustManager[] { tm }, null);
            }
        } catch (KeyStoreException e) {
            Log.d("SSLClient", e.getMessage());
        } catch (NoSuchAlgorithmException e) {
            Log.d("SSLClient", e.getMessage());
        } catch (CertificateException e) {
            Log.d("SSLClient", e.getMessage());
        } catch (IOException e) {
            Log.d("SSLClient", e.getMessage());
        } catch (KeyManagementException e) {
            Log.d("SSLClient", e.getMessage());
        } catch (UnrecoverableKeyException e) {
            Log.d("SSLClient", e.getMessage());
        }
    }
}

package com.example.mark.sslclient;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;

import javax.net.ssl.SSLSocket;
import javax.net.ssl.SSLSocketFactory;

public class MainActivity extends AppCompatActivity {
    private static final String TAG = "MainActivity";
    private SSLClient sslClient;

    private Runnable threadMain = new Runnable() {
        @Override        public void run() {
            SSLSocketFactory socketFactory = (SSLSocketFactory)sslClient.ssl_ctx.getSocketFactory();
            try {
                Log.d(TAG, "threadMain createSocket a");
                SSLSocket socket = (SSLSocket)socketFactory.createSocket("192.168.1.61", 8080);
                Log.d(TAG, "threadMain createSocket b");
                PrintWriter output = new PrintWriter(new OutputStreamWriter(socket.getOutputStream()));
                BufferedReader input = new BufferedReader((new InputStreamReader(socket.getInputStream())));
                output.println("\nthis is from client+++++++++++++++client send to server");
                output.flush();
                Log.d(TAG, "threadMain input.readLine() a");
                String line = input.readLine();
                while (line != null) {
                    Log.d(TAG, line);
                    line = input.readLine();
                }
                Log.d(TAG, "threadMain input.readLine() b");
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    };
    @Override    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Log.d(TAG, "onCreate a");
        setContentView(R.layout.activity_main);

        sslClient = new SSLClient(this);
        Thread thread = new Thread(threadMain);
        thread.start();
        Log.d(TAG, "onCreate b");
    }
}