Fez Panda II Serial Communication


I have a FEZ Panda II connected to a Windows PC. On the Panda side, i use the COM1 pins (D0 + D1 + GND) on the windows side, I use COM1 (only physical serial port).

My problem is that I do not receive on the PC what i send from the Panda. I tried sending 0x4F, 0x4B (OK in Ascii) every second, but it is somehow garbled on the way to the PC.

On the PC side i read 0x58, 0x5A, 0x00, 0xB0, 0x5A, 0x00, 0x58, 0x5A, 0x00, 0x58, 0x5A, 0x00, 0xB0, 0x5A, 0x00, 0x58

Both ends are configured to use 4800 bps None parity, 8 data bits and 1 stop bit.

I tried switching to COM2 on the Panda as well, but it had the same result.

Anybody seen this problem before?


SerialPort port = new SerialPort(Serial.COM1, 4800, Parity.None, 8, StopBits.One);

        byte[] ok = System.Text.Encoding.UTF8.GetBytes("OK");
        while (true)
            // Sleep for 1000 milliseconds

            // toggle LED state
            ledState = !ledState;

            port.Write(ok, 0, ok.Length);


SerialPort port = new SerialPort(“COM1”, 4800, Parity.None, 8, StopBits.One);

        Stream stream = port.BaseStream;

        int value = 0;
        while ((value = stream.ReadByte()) >= 0)
            Console.WriteLine( value.ToString("X2"));

I hope you didn’t blow the pins on your panda! You need a TTL to RS232 to connect it that way.

Close on the code tags… use square brackets instead and they’ll work, or click the 101010 icon at the top of each message.

You cannot connect Panda UART directly to a PC COM port (RS232). As EriSan500 says, you may damage your Panda. You need a FTDI chip in between to safely translate the signal. Start with the this tutorial http://wiki.tinyclr.com/index.php?title=UART_-_PC_Communication

Wow - in my ignorance I just connected the pins as I thought was correct.

I will look at the link in greater details - thanks for your help!

So if I read the article correct, by plugging in this http://www.cutedigi.com/prototyping/general-257/uart-to-rs232-interface-card-uart-rs232.html it should work?

Maybe even this? http://www.cutedigi.com/arduino-shields/rs232-shield-for-arduino.html
Does anybody know if it is pin compatible?

Either of those will work. The Arduino shield is pin compatible with COM1 on the Panda2. You can also get something called an FTDI Friend, e.g. FTDI Friend + extras [v1.0] : ID 284 : $14.75 : Adafruit Industries, Unique & fun DIY electronics and kits , which will create a virtual COM port via USB. This is nice because newer computers generally don’t have physical COM ports.