ColorPAL documentation

Direct Commands

To begin programming the ColorPAL, you will need to be in Direct mode. In this mode, the ColorPAL will

accept any of four different commands. These are:

• = (Equal sign): Begin buffering commands.

• ! (Exclamation point): Begin executing the buffered code.

• # (Pound sign): Save the buffered code to an address in EEPROM.

• + (Plus sign): Receive a “network” address.

Begin Buffering Commands

Execute Buffered Commands

Any programming (i.e. color-related) commands that the ColorPAL executes must first be buffered before

they can be executed. Here is a typical buffer-and-execute sequence that causes the RGB LED to light up

red:

SEROUT sio, baud, ["= R !"]

Note: Any blanks embedded

within a buffered command sequence

(i.e. after the “=” and before a “!” or

“#”) are optional and can be added to enhance program readability. Adding them affects neither the

speed of a program nor the amount of memory it requires. However,

do not embed blanks in a direct

command sequence!

Doing so will cause the ColorPAL’s automatic baud rate detection to fail.

#nn

Save Buffered Program to EEPROM

Saving a program to EEPROM requires an address to be supplied in hexadecimal and ranging from 00 to

3F.

All

numerical arguments passed to the ColorPAL are done so as two-digit hexadecimal constants (00

to FF). To store the “light up red” program to EEPROM location zero (for automatic startup), say, you’d

do this:

SEROUT sio, baud, ["= R #00"]

This, along with the prior example, also illustrates that both the execute (!) and save (#) commands will

immediately exit Buffer mode and enter Direct mode.

IMPORTANT: If the program you save starts automatically (i.e. is stored at location 00) and outputs

data, it will do so at an uncalibrated baud rate, somewhere around 4800 baud. The reason is that the

ColorPAL calibrates its baud rate from commands sent to it in Direct mode. Lacking any such commands

when autostarting, it has to pick a default value. Because the ColorPAL uses an RC oscillator for its

timebase, it’s hard to predict with any degree of accuracy what the actual output baud rate will be.

There are two ways around this. One is to restart the stored program manually by entering Direct mode

and issuing an Execute command. The ColorPAL will pick up the desired baud rate from this.

The other option is to auto-detect the baud rate at which the ColorPAL is transmitting and use it instead.

Here’s a PBASIC program that will do that. It will work with any BASIC Stamp, except the BS2px: