So I just purchased a FEZ Cerbuino Bee board and a Parallax gryoscope to do some development, trying to get my feet wet in some hardware/software development. I am trying to use SPI protocol for communication between the devices. According to the pinout found at https://www.ghielectronics.com/docs/45/fez-cerbuino-bee-developer#396, here is
FEZ GYROSCOPE
PIN PB3 SPI1 SCK SCL
PIN PB4 SPI1 MISO SDO
PIN PB5 SPI1 MOSI SDA/SDI/SDO
PIN PB15 CS
Here is the problem that I am encountering. Whenever the SDO pin is connected to the MISO/PB4 pin the FEZ board locks up. For I2C communication, I am also confused as to which pins to use, not a well documented board for a newbie.
Please let me know if anyone has this configured to work with similar devices on this particular board using the Arduino style headers.
Thanks,
Kirk
I have a code for that device.
namespace Test
{
public class Gyro : I2CDevice
{
public const byte L3G4200D_WHO_AM_I = 0x0F;
public const byte L3G4200D_CTRL_REG1 = 0x20;
public const byte L3G4200D_CTRL_REG2 = 0x21;
public const byte L3G4200D_CTRL_REG3 = 0x22;
public const byte L3G4200D_CTRL_REG4 = 0x23;
public const byte L3G4200D_CTRL_REG5 = 0x24;
public const byte L3G4200D_REFERENCE = 0x25;
public const byte L3G4200D_OUT_TEMP = 0x26;
public const byte L3G4200D_STATUS_REG = 0x27;
public const byte L3G4200D_OUT_X_L = 0x28;
public const byte L3G4200D_OUT_X_H = 0x29;
public const byte L3G4200D_OUT_Y_L = 0x2A;
public const byte L3G4200D_OUT_Y_H = 0x2B;
public const byte L3G4200D_OUT_Z_L = 0x2C;
public const byte L3G4200D_OUT_Z_H = 0x2D;
public const byte L3G4200D_FIFO_CTRL_REG = 0x2E;
public const byte L3G4200D_FIFO_SRC_REG = 0x2F;
public const byte L3G4200D_INT1_CFG = 0x30;
public const byte L3G4200D_INT1_SRC = 0x31;
public const byte L3G4200D_INT1_THS_XH = 0x32;
public const byte L3G4200D_INT1_THS_XL = 0x33;
public const byte L3G4200D_INT1_THS_YH = 0x34;
public const byte L3G4200D_INT1_THS_YL = 0x35;
public const byte L3G4200D_INT1_THS_ZH = 0x36;
public const byte L3G4200D_INT1_THS_ZL = 0x37;
public const byte L3G4200D_INT1_DURATION = 0x38;
OutputPort csPort;
private int m_Timeout = 1000;
// int Addr = 105; // 0x69 Adress for L3G4200D
private ushort m_Address;
public Gyro(Cpu.Pin cs) : this(0x69, cs)
{ }
public Gyro(ushort address, Cpu.Pin cs)
: base(new Configuration(address, 100))
{
m_Address = address;
csPort = new OutputPort(cs, true);
}
public byte[] Read(byte memoryAddress, int responseLength = 1)
{
var buffer = new byte[responseLength];
I2CDevice.I2CTransaction[] transaction;
transaction = new I2CDevice.I2CTransaction[]
{
I2CDevice.CreateWriteTransaction(new byte[] { memoryAddress }),
I2CDevice.CreateReadTransaction(buffer)
};
int result = Execute(transaction, m_Timeout);
return buffer;
}
public void Write(byte memoryAddress, byte value)
{
I2CTransaction[] transaction;
transaction = new I2CDevice.I2CTransaction[]
{
I2CDevice.CreateWriteTransaction(new byte[] { memoryAddress, value })
};
int result = Execute(transaction, m_Timeout);
}
byte[] buffer = null;
internal void Read(ref int x, ref int y, ref int z)
{
buffer = Read(L3G4200D_OUT_X_H);
x = buffer[0] << 8;
buffer = Read(L3G4200D_OUT_X_L);
x |= buffer[0];
buffer = Read(L3G4200D_OUT_Y_H);
y = buffer[0] << 8;
buffer = Read(L3G4200D_OUT_Y_L);
y |= buffer[0];
buffer = Read(L3G4200D_OUT_Z_H);
z = buffer[0] << 8;
buffer = Read(L3G4200D_OUT_Z_L);
z |= buffer[0];
x = (x&0x8000) != 0 ? -(short)~(x - 1) : x;
y = (y & 0x8000) != 0 ? -(short)~(y - 1) : y;
z = (z & 0x8000) != 0 ? -(short)~(z - 1) : z;
x /= 114;
y /= 114;
z /= 114;
}
}
//public class Program
//{
// public static void Main()
// {
// Gyro t = new Gyro();
// t.Write(0x1F, 0x20); // Turn on XYZ axes
// t.Write(0x08, 0x22); // control
// t.Write(0x80, 0x23); // Scale to 500 deg/sec
// Thread.Sleep(1000);
// int timerPeriod = 50;
// Timer timer = new Timer(delegate(object o)
// {
// byte[] MSBx = t.Read(0x29, 1);
// byte[] LSBx = t.Read(0x28, 1);
// int x = ((MSBx[0] << 8) | LSBx[0]);
// byte[] MSBy = t.Read(0x2B, 1);
// byte[] LSBy = t.Read(0x2A, 1);
// int y = ((MSBy[0] << 8) | LSBy[0]);
// byte[] MSBz = t.Read(0x2D, 1);
// byte[] LSBz = t.Read(0x2C, 1);
// int z = ((MSBz[0] << 8) | LSBz[0]);
// Debug.Print("X: " + x + " Y: " + y + " Z: " + z);
// }, null, 0, timerPeriod);
// // Make sure the device runs the timer and doesnt end execution.
// while (true)
// {
// Thread.Sleep(Timeout.Infinite);
// }
// }
//}
}
Edit:
For I2C you or only need SCL and SDA pins. Ignore CS in the code above. I think it is a leftover from the attempt to get it working using SPI.
Thanks for a speedy response. Do you mind if I try this code sample? And what were the pins used for I2C?
On Cerbuino Bee you need to use Pin8 (SDA) on Gadgeteer Socket 2 and Pin9 (SCL) on Gadgeteer Socket 2. These are the hardware I2C1 pins.
If not sure you can always check with the schematics:
http://www.ghielectronics.com/downloads/schematic/FEZ_Cerbuino_Bee_SCH.PDF
I just finished writing some code to get Gyro, Accelerometer and Temperature from a cheap MPU6050 breakout board that I got from AliExpress. It works quite well, but now I just need an idea for a project to use it in! 
