Cypress Semiconductor I2C-USB Bridge Kit - Kwynn's notes for Windows 7

My earliest, unmodified copy of Leitner's ZIP file with source code and DLL--see hashes and other bibliography below.

Cypress' driver probably does not work beyond Windows XP. Leitner's code works in Windows 7--usage example below--and it doesn't need any Cypress drivers. Another advantage of his code is that there is no end-user-level installation necessary such as Cypress' usb2iic.exe.

The Bridge Kit comes with a "Slave" Demo Board with two red LEDs on it. The following C# code uses two checkboxes to turn the lights on and off with check and uncheck. This was the third driver I used to work with the board. There is probably more background when you read about the first driver--Cypress' own driver. I also wrote code that uses libUSB that works in both Linux and Windows.


/*
<![CDATA[
*/

// Kwynn Buess - Cypress Semiconductor CY3240 project - 2011/06/16 then 24th
// more details at http://kwynn.com/t/1/03/Cypress_notes.html

using System;
using System.Windows.Forms;
using USBHIDDRIVER; // (c) 2007 by Florian Leitner http://www.florian-leitner.de
using System.Threading;

namespace OnOff2Light
{
public partial class OnOffForm : Form
{
USBHIDDRIVER.USBInterface usb;

public OnOffForm() {
    InitializeComponent();
    initOnOff();
}

public void initOnOff()      {
	usb = new USBInterface("vid_04b4", "pid_f232"); // vendor and product ID of Cypress Bridge
	usb.Connect(); 
	speedPower();
	
	Thread.Sleep(40); // I sometimes get errors without delays, especially for the first few calls
	onOff(1, false);  // sometimes the lights both come on at power-up, so 
	Thread.Sleep(40); // turn them off
	onOff(2, false);
}

private void speedPower() { 
	byte[] data = new Byte[4];
	
	// data[3] = 0x01; this is 5v; 0x00 is no power
	data[0] = 0x0a; data[1] = 0x01; data[2] = 0x80; data[3] = 0x01; 
	usb.write(data);

	// 0x28 = 50 K - slowest speed; 0x20 = 100; 0x24 = 400 
	data[0] = 0x28; data[1] = 0x01; data[2] = 0x80; data[3] = 0x01;
	usb.write(data);
}

private void onOff(byte lightNum, bool turnOn)
{
    byte[] data = new byte[12];  
    
    data[8] = lightNum;
    
    // always data[10] = 0x01 for the slave demo board
    data[0] = 0x0a; data[1] = 0x08; data[10] = 0x01;
    
    for (byte i = 2; i <= 7; i++) data[i] = 0x00;
	
    if (turnOn) data[9] = 0xff; else data[9] = 0;
    
    usb.write(data);
}

private void buttonClick(object sender, EventArgs e)
{
	bool turnOn;
    CheckBox temp = (CheckBox)sender;
    if (temp.Checked) turnOn = true; else turnOn = false;

	byte lightNum;    
    if (temp.Name == "checkBox1") lightNum = 0x01; // which light
    else lightNum = 0x02;
    
    onOff(lightNum, turnOn);

} // end function
} // end class
} // end namespace
/*
]]>
*/

Extra Control Bytes - SniffUSB

One difference between this driver and the other two is that I had to figure out some additional input bytes. Cypress has some doc on this, but I found SniffUSB very helpful with this. It allowed me to watch the USB packets to figure out what I needed to send.

Bibliography

SniffUSB by Thomas F. Divine of Printing Communications Associates, Inc. ("PCA" or "PCAUSA"). I was using 2.0.0006, released (most likely) February 23, 2007.

Leitner's source code comes as csharp-usb-hid-driver.zip. The DLL is USBHIDDRIVER.dll.

Cypress Semiconductor I2C-USB Bridge Kit Project--Windows 7 usage, working code, etc.

Working in Windows 7--Leitner's GPL Code

Extra Control Bytes - SniffUSB

Bibliography

More on Leitner's ZIP file and Leitner

Page(s) History (earlier)

Page History, 2014