Enabling Multiple Light Tracking Using Kevin's Code

[DanDon]

void Set_Poll_Mode(void)
{
Write_Camera_Serial_Port('P');
Write_Camera_Serial_Port('M');
Write_Camera_Serial_Port(1);
Write_Camera_Serial_Port(1);
}

That should set the camera into poll mode if the camera was set into raw mode before this function call.

[Mitch]

Originally Posted by dhoizner

That should set the camera into poll mode if the camera was set into raw mode before this function call.

Thank you, I'll try this. I thought every command needed to be ended with a carriage return? No?

[JohnC]

Originally Posted by Mitch

Thank you, I'll try this. I thought every command needed to be ended with a carriage return? No?

From what I understand, no, not if the camera is in poll mode. You send at least 4 characters: two for the command, one for the number of arguments, and one for each argument. That's why there are 2 "1"s being sent. One of them is an argument count, and the other is the actual argument. In poll mode no carriage returns are sent.

[JBotAlan]

Originally Posted by Mitch

Thank you, I'll try this. I thought every command needed to be ended with a carriage return? No?

Nope--Kevin's code by default sets the camera to "Raw mode"--see the command RM in the CMUcam manual. His code sends a "RM 5" command; 5 = 101; that means input and output are in raw bytes instead of the normal "XX 1 2 3\r" style. As you can see, "XX 1 2 3\r" is 9 bytes, "XX3123" is only 6. Raw mode is there to trim the fat out of the communications. Just a quote from the manual:

If bit 2 is set, input will be read as raw byte values, too. In this mode, after the two command byte values are sent, send 1 byte telling how many arguments are to follow. (i.e. DF followed by the raw byte value 0 for no arguments) No \r character is required.

It's not explained very well, but basically, you send the two-byte command, a byte with the number of arguments, and each argument after that is sent as a single byte.

Good luck,
JBot

EDIT: John, it has nothing to do with when the camera is in poll mode, rather, if it is in raw mode, it will act as I described above. If it is in poll mode, TC (track color) sends 1 T packet, if not, it sends them repeatedly until interrupted by a \r.