I hooked up RF 433 receiver to NetDuino in order to receive RF transmissions from Oregon Scientific THGN122 sensor.
RF Receiver: http://www.hwkitchen...hz-rf-link-kit/
I simply set data out of receiver to RX pin for COM2:
// initialize the serial port for COM2 (using D2 & D3) rf433 = new SerialPort(SerialPorts.COM2, 115200, Parity.None, 8, StopBits.One); // open the serial-port, so we can send & receive data rf433.Open(); // add an event-handler for handling incoming data rf433.DataReceived += new SerialDataReceivedEventHandler(rf433_DataReceived);
In the datareceived handler I am buffering incoming data till size is 1024 btes and then dumping it to SD card as text file (converted to hex)
static void rf433_DataReceived(object sender, SerialDataReceivedEventArgs e)
{
int count = 1024;
byte[] ComBuffer = new byte[count];
int readBytes = 0;
int totalReadBytes = 0;
int offset = 0;
int remaining = 1024;
string RFLogPath = @"\SD\rflogout.txt";
//buffer received
try
{
do
{
readBytes = rf433.Read(ComBuffer, offset, remaining);
offset = offset + readBytes;
remaining = remaining - readBytes;
totalReadBytes = totalReadBytes + readBytes;
} while (remaining > 0 && readBytes > 0);
}
catch (System.Exception ex)
{
byte[] temp = new byte[totalReadBytes - 1];
if (ComBuffer != null)
Array.Copy(ComBuffer, temp, System.Math.Min(ComBuffer.Length, temp.Length));
ComBuffer = temp;
}
//save to file
using (StreamWriter writer = new StreamWriter(RFLogPath, true))
{
writer.WriteLine(DateTime.Now.ToString() + ":");
for (int i = 0; i < ComBuffer.Length; i++)
{
writer.Write(ByteToHex(ComBuffer[i]) + "-");
}
writer.Flush();
}
}
This is producing file as attached but I am unable to decipher any repeating transmissions.
I set up port speed to 115200 to avoid loosing some data but it looks like 1024 buffer fills up in cca 6 - 7 seconds.
Also I see a lot of traffic so I suspect that there is a number of devices around since bytes keep coming up even if I disconnect my sensor.
Anyone can help with deciphering or recognizing byte pattern of Oregon sensor ?
Thanx,
DiNo
Attached Files
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rflogout.txt 160.15KB
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