VDIP1 USB Host Controller

I got my VDIP1 USB Host controller from Saelig today and was able to get it hooked up and reading a Flash drive in a couple hours. Because the Arduino only has one TX / RX serial pin if you connect it using them you cannot communicate with the computer over the built in USB UART on the Arduino. To get around this limitation there are a number of libraries that allow serial communication over non-serial pins.

I chose the NewSoftSerial library to give access to the VDIP1.  The first attempt was to use the AFSoftLibrary and it just did not work properly causing some strange looping of the Setup() method.  After switching to the NewSoftSerial library everything started working and I had no trouble doing a DIR and creating a new file on the flash drive.  I am posting an early version of the sketch just so i can get a good example and a picture / schematic out so expect updates later.  Keep reading for the schema, pic and sketch.

Update: I changed the sketch and schematic / pic to include the RTS / CTS flow control.

VDIP1 USB Host Controller Wiring

Click here to see the picture and sketch.

Picture of the wiring I used with the sketch.

Arduino USB Host Controller with Flash Disk

I did a little cleaning of the wiring and put it on a proto-shield.

Protoshield new wiring

The sketch allows sending of any command via the Serial monitor for doing testing. Some common commands would be “~DIR~ ~CD DIRNAME~ ~CD ..~” See the VDIP1 command list for the full file operations.


// RX TX
#include

NewSoftSerial usb(2, 3);

int RTSPin = 5;
int CTSPin = 4;

void setup() {
pinMode(RTSPin, INPUT);
pinMode(CTSPin, OUTPUT);

usb.begin(9600);
//usb.begin(57600); // You can modify the default speed of the VDIP1 with firmware updates to be up to 57600 through newSoftSerial.
digitalWrite(CTSPin, LOW); // Set the CTS to low and keep it there.
Serial.begin(9600); // opens serial port, sets data rate to 9600 bps

Serial.print("Starting");

usb.print("IPA"); // Set to ascii mode.
usb.print(13, BYTE);
}

char usbRx;
byte charIn;

void SendToUsb(char val) {
while (digitalRead(RTSPin) == HIGH) { }
usb.print(val);
digitalWrite(CTSPin, LOW);
}

void SendToUsbTermCmd() {
while (digitalRead(RTSPin) == HIGH) { }
usb.print(13, BYTE);
digitalWrite(CTSPin, LOW);

}

void loop() {
// Disable the sending on the USB device if you have filled more than 50% of your buffer (64 bytes by default)
if (usb.available() > 32) {
digitalWrite(CTSPin, HIGH);
} else {
digitalWrite(CTSPin, LOW);
}
if (usb.available() > 0) { // read the incoming byte
usbRx = usb.read();
if (usbRx == 0x0D) {
Serial.println();
} else {
Serial.print(usbRx);
}
}
if (Serial.available() > 0) { // read the incoming byte
if (Serial.read() == (byte)'~') {
charIn = 0;
while (charIn != (byte)'~') { // wait for header byte again
if (Serial.available() > 0) {
charIn = Serial.read();
Serial.print(charIn, HEX);
if (charIn == (byte)'~') {
Serial.println("breaking");
break;
}
SendToUsb(charIn);
}
}
SendToUsbTermCmd();
}
}
}

Advertisement