Lo scopo e' sempre il solito: creare un sistema che permette di scrivere in automatico un file su una chiavetta USB all'inserimento della stessa.
Il sistema era gia' funzionante con Raspberry ma una delle richieste del sistema e' quella di essere alimentato a batteria e la batteria deve durare almeno 48 ore; visto che con Raspberry una batteria da 5000 mA e' durata circa una notte ho modificato il progetto per usare Arduino (nello specifico una Nano) ed il modulo CH376S sperando in consumi minori
Il modulo CH376S e' chip specifico per effettuare scrittura e lettura di file system che puo' essere pilotato da Arduino.
I collegamenti sono banali (4 fili)
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| Fonte : http://arduinobasics.blogspot.it/2015/05/ch376s-usb-readwrite-module.html |
Per questa prova ho modificato il codice ripreso da questo link
Il nucleo del programma e' evidenziato in giallo: prima controllare che il modulo USB sia connesso, dopo controlla che ci sia un dispositivo USB inserito, infine scrive il file
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#include <SoftwareSerial.h>
byte computerByte; //used to store data coming from the computer
byte USB_Byte; //used to store data coming from the USB stick
int LED = 13; //the LED is connected to digital pin 13
int timeOut = 2000; //TimeOut is 2 seconds. This is the amount of time you wish to wait for a response from the CH376S module.
String wrData = "Lanterna 2000"; //We will write this data to a newly created file.
SoftwareSerial USB(10, 11); // Digital pin 10 on Arduino (RX) connects to TXD on the CH376S module
// Digital pin 11 on Arduino (TX) connects to RXD on the CH376S module
// GND on Arduino to GND on CH376S module
// 5V on Arduino to 5V on CH376S module
int connessione;
int chiave_presente;
//==============================================================================================================================================
void setup() {
Serial.begin(9600); // Setup serial communication with the computer (using a baud rate of 9600 on serial monitor)
USB.begin(9600); // Setup serial communication with the CH376S module (using the default baud rate of 9600)
pinMode(LED,OUTPUT); // Define digital pin 13 as an OUTPUT pin - so that we can use it with an LED
digitalWrite(LED,LOW); // Turn off the LED
Serial.println("Iniziato");
}
//================================================================================================================================================
void loop() {
connessione = 0;
chiave_presente = 0;
checkConnection(0x01);
if (connessione == 1)
{
Serial.println("Connessione Presente");
set_USB_Mode(0x06);
if (chiave_presente == 1)
{
resetALL();
writeFile("lant200.txt", wrData);
Serial.println("************FINE*************");
}
}
if(USB.available()){ // This is here to capture any unexpected data transmitted by the CH376S module
Serial.print("CH376S has just sent this code:");
Serial.println(USB.read(), HEX);
}
delay(5000);
}
//END OF LOOP FUNCTION ========================================================================================================================================
void checkConnection(byte value){
USB.write(0x57);
USB.write(0xAB);
USB.write(0x06);
USB.write(value);
if(waitForResponse("checking connection")){ //wait for a response from the CH376S. If CH376S responds, it will be true. If it times out, it will be false.
if(getResponseFromUSB()==(255-value)){
//Serial.println(">Connection to CH376S was successful.");
connessione = 1;
} else {
//Serial.print(">Connection to CH376S - FAILED.");
connessione = 0;
}
}
}
void set_USB_Mode (byte value){
USB.write(0x57);
USB.write(0xAB);
USB.write(0x15);
USB.write(value);
delay(20);
if(USB.available()){
USB_Byte=USB.read();
//Check to see if the command has been successfully transmitted and acknowledged.
if(USB_Byte==0x51){ // If true - the CH376S has acknowledged the command.
//Serial.println("set_USB_Mode command acknowledged"); //The CH376S will now check and monitor the USB port
USB_Byte = USB.read();
//Check to see if the USB stick is connected or not.
if(USB_Byte==0x15){ // If true - there is a USB stick connected
//Serial.println("USB is present");
chiave_presente = 1;
blinkLED(); // If the process was successful, then turn the LED on for 1 second
} else {
chiave_presente = 0;
//Serial.print("USB Not present. Error code:"); // If the USB is not connected - it should return an Error code = FFH
//Serial.print(USB_Byte, HEX);
//Serial.println("H");
}
} else {
//Serial.print("CH3765 error! Error code:");
//Serial.print(USB_Byte, HEX);
//Serial.println("H");
chiave_presente = 0;
}
}
delay(20);
}
//resetALL=========================================================================================
//This will perform a hardware reset of the CH376S module - which usually takes about 35 msecs =====
void resetALL(){
USB.write(0x57);
USB.write(0xAB);
USB.write(0x05);
//Serial.println("The CH376S module has been reset !");
delay(200);
}
void writeFile(String fileName, String data){
resetALL(); //Reset the module
set_USB_Mode(0x06); //Set to USB Mode
diskConnectionStatus(); //Check that communication with the USB device is possible
USBdiskMount(); //Prepare the USB for reading/writing - you need to mount the USB disk for proper read/write operations.
setFileName(fileName); //Set File name
if(fileCreate()){ //Try to create a new file. If file creation is successful
fileWrite(data); //write data to the file.
} else {
Serial.println("File could not be created, or it already exists");
}
fileClose(0x01);
}
void setFileName(String fileName){
Serial.print("Setting filename to:");
Serial.println(fileName);
USB.write(0x57);
USB.write(0xAB);
USB.write(0x2F);
USB.write(0x2F); // Every filename must have this byte to indicate the start of the file name.
USB.print(fileName); // "fileName" is a variable that holds the name of the file. eg. TEST.TXT
USB.write((byte)0x00); // you need to cast as a byte - otherwise it will not compile. The null byte indicates the end of the file name.
delay(20);
}
void diskConnectionStatus(){
USB.write(0x57);
USB.write(0xAB);
USB.write(0x30);
if(waitForResponse("Connecting to USB disk")){ //wait for a response from the CH376S. If CH376S responds, it will be true. If it times out, it will be false.
if(getResponseFromUSB()==0x14){ //CH376S will send 0x14 if this command was successful
} else {
}
}
}
void USBdiskMount(){
Serial.println("Mounting USB disk");
USB.write(0x57);
USB.write(0xAB);
USB.write(0x31);
if(waitForResponse("mounting USB disk")){ //wait for a response from the CH376S. If CH376S responds, it will be true. If it times out, it will be false.
if(getResponseFromUSB()==0x14){ //CH376S will send 0x14 if this command was successful
} else {
}
}
}
void fileOpen(){
Serial.println("Opening file.");
USB.write(0x57);
USB.write(0xAB);
USB.write(0x32);
if(waitForResponse("file Open")){ //wait for a response from the CH376S. If CH376S responds, it will be true. If it times out, it will be false.
if(getResponseFromUSB()==0x14){ //CH376S will send 0x14 if this command was successful
} else {
}
}
}
//setByteRead=====================================================================================
//This function is required if you want to read data from the file.
boolean setByteRead(byte numBytes){
boolean bytesToRead=false;
int timeCounter = 0;
USB.write(0x57);
USB.write(0xAB);
USB.write(0x3A);
USB.write((byte)numBytes); //tells the CH376S how many bytes to read at a time
USB.write((byte)0x00);
if(waitForResponse("setByteRead")){ //wait for a response from the CH376S. If CH376S responds, it will be true. If it times out, it will be false.
if(getResponseFromUSB()==0x1D){ //read the CH376S message. If equal to 0x1D, data is present, so return true. Will return 0x14 if no data is present.
bytesToRead=true;
}
}
return(bytesToRead);
}
//getFileSize()===================================================================================
//writes the file size to the serial Monitor.
int getFileSize(){
int fileSize=0;
Serial.println("Getting File Size");
USB.write(0x57);
USB.write(0xAB);
USB.write(0x0C);
USB.write(0x68);
delay(100);
Serial.print("FileSize =");
if(USB.available()){
fileSize = fileSize + USB.read();
}
if(USB.available()){
fileSize = fileSize + (USB.read()*255);
}
if(USB.available()){
fileSize = fileSize + (USB.read()*255*255);
}
if(USB.available()){
fileSize = fileSize + (USB.read()*255*255*255);
}
Serial.println(fileSize);
delay(10);
return(fileSize);
}
//fileRead========================================================================================
//read the contents of the file
void fileRead(){
Serial.println("Reading file:");
byte firstByte = 0x00; //Variable to hold the firstByte from every transmission. Can be used as a checkSum if required.
byte numBytes = 0x40; //The maximum value is 0x40 = 64 bytes
while(setByteRead(numBytes)){ //This tells the CH376S module how many bytes to read on the next reading step. In this example, we will read 0x10 bytes at a time. Returns true if there are bytes to read, false if there are no more bytes to read.
USB.write(0x57);
USB.write(0xAB);
USB.write(0x27); //Command to read ALL of the bytes (allocated by setByteRead(x))
if(waitForResponse("reading data")){ //Wait for the CH376S module to return data. TimeOut will return false. If data is being transmitted, it will return true.
firstByte=USB.read(); //Read the first byte
while(USB.available()){
Serial.write(USB.read()); //Send the data from the USB disk to the Serial monitor
delay(1); //This delay is necessary for successful Serial transmission
}
}
if(!continueRead()){ //prepares the module for further reading. If false, stop reading.
break; //You need the continueRead() method if the data to be read from the USB device is greater than numBytes.
}
}
Serial.println();
Serial.println("NO MORE DATA");
}
//fileWrite=======================================================================================
//are the commands used to write to the file
void fileWrite(String data){
Serial.println("Writing to file:");
byte dataLength = (byte) data.length(); // This variable holds the length of the data to be written (in bytes)
Serial.println(data);
Serial.print("Data Length:");
Serial.println(dataLength);
delay(100);
// This set of commands tells the CH376S module how many bytes to expect from the Arduino. (defined by the "dataLength" variable)
USB.write(0x57);
USB.write(0xAB);
USB.write(0x3C);
USB.write((byte) dataLength);
USB.write((byte) 0x00);
if(waitForResponse("setting data Length")){ // Wait for an acknowledgement from the CH376S module before trying to send data to it
if(getResponseFromUSB()==0x1E){ // 0x1E indicates that the USB device is in write mode.
USB.write(0x57);
USB.write(0xAB);
USB.write(0x2D);
USB.print(data); // write the data to the file
if(waitForResponse("writing data to file")){ // wait for an acknowledgement from the CH376S module
}
Serial.print("Write code (normally FF and 14): ");
Serial.print(USB.read(),HEX); // code is normally 0xFF
Serial.print(",");
USB.write(0x57);
USB.write(0xAB);
USB.write(0x3D); // This is used to update the file size. Not sure if this is necessary for successful writing.
if(waitForResponse("updating file size")){ // wait for an acknowledgement from the CH376S module
}
Serial.println(USB.read(),HEX); //code is normally 0x14
}
}
}
//continueRead()==================================================================================
//continue to read the file : I could not get this function to work as intended.
boolean continueRead(){
boolean readAgain = false;
USB.write(0x57);
USB.write(0xAB);
USB.write(0x3B);
if(waitForResponse("continueRead")){ //wait for a response from the CH376S. If CH376S responds, it will be true. If it times out, it will be false.
if(getResponseFromUSB()==0x14){ //CH376S will send 0x14 if this command was successful
readAgain=true;
}
}
return(readAgain);
}
//fileCreate()========================================================================================
//the command sequence to create a file
boolean fileCreate(){
boolean createdFile = false;
USB.write(0x57);
USB.write(0xAB);
USB.write(0x34);
if(waitForResponse("creating file")){ //wait for a response from the CH376S. If file has been created successfully, it will return true.
if(getResponseFromUSB()==0x14){ //CH376S will send 0x14 if this command was successful
createdFile=true;
}
}
return(createdFile);
}
//fileDelete()========================================================================================
//the command sequence to delete a file
void fileDelete(String fileName){
setFileName(fileName);
delay(20);
USB.write(0x57);
USB.write(0xAB);
USB.write(0x35);
if(waitForResponse("deleting file")){ //wait for a response from the CH376S. If file has been created successfully, it will return true.
if(getResponseFromUSB()==0x14){ //CH376S will send 0x14 if this command was successful
Serial.println("Successfully deleted file");
}
}
}
//filePointer========================================================================================
//is used to set the file pointer position. true for beginning of file, false for the end of the file.
void filePointer(boolean fileBeginning){
USB.write(0x57);
USB.write(0xAB);
USB.write(0x39);
if(fileBeginning){
USB.write((byte)0x00); //beginning of file
USB.write((byte)0x00);
USB.write((byte)0x00);
USB.write((byte)0x00);
} else {
USB.write((byte)0xFF); //end of file
USB.write((byte)0xFF);
USB.write((byte)0xFF);
USB.write((byte)0xFF);
}
if(waitForResponse("setting file pointer")){ //wait for a response from the CH376S.
if(getResponseFromUSB()==0x14){ //CH376S will send 0x14 if this command was successful
Serial.println("Pointer successfully applied");
}
}
}
//fileClose=======================================================================================
//closes the file
void fileClose(byte closeCmd){
Serial.println("Closing file:");
USB.write(0x57);
USB.write(0xAB);
USB.write(0x36);
USB.write((byte)closeCmd); // closeCmd = 0x00 = close without updating file Size, 0x01 = close and update file Size
if(waitForResponse("closing file")){ // wait for a response from the CH376S.
byte resp = getResponseFromUSB();
if(resp==0x14){ // CH376S will send 0x14 if this command was successful
Serial.println(">File closed successfully.");
} else {
Serial.print(">Failed to close file. Error code:");
Serial.println(resp, HEX);
}
}
}
//waitForResponse===================================================================================
//is used to wait for a response from USB. Returns true when bytes become available, false if it times out.
boolean waitForResponse(String errorMsg){
boolean bytesAvailable = true;
int counter=0;
while(!USB.available()){ //wait for CH376S to verify command
delay(1);
counter++;
if(counter>timeOut){
Serial.print("TimeOut waiting for response: Error while: ");
Serial.println(errorMsg);
bytesAvailable = false;
break;
}
}
delay(1);
return(bytesAvailable);
}
//getResponseFromUSB================================================================================
//is used to get any error codes or messages from the CH376S module (in response to certain commands)
byte getResponseFromUSB(){
byte response = byte(0x00);
if (USB.available()){
response = USB.read();
}
return(response);
}
//blinkLED==========================================================================================
//Turn an LED on for 1 second
void blinkLED(){
digitalWrite(LED, HIGH);
delay(100);
digitalWrite(LED,LOW);
}
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