pat. Object

The pat. object allows you to "play" signal patterns on up to five LED pairs, with each pair consisting of a green and red LED.

The channel to work with is selected through the pat.channel property. The first channel (channel 0) is the primary channel of your system. It utilizes the green and red status LEDs that are present on all external devices, boards, and some modules offered by Tibbo. All modules have SG and SR I/O lines that are meant for controlling external status LEDs. Note that when a Tibbo BASIC/C application is not running, the green and red status LEDs are used to display various status information.

The remaining four channels (channel 1-4) are identical in function, but use regular I/O lines of Tibbo devices. Moreover, the pat.greenmap and pat.redmap properties allow you to flexibly map the green and red LED control lines of each channel to any I/O lines of the device.

The pattern you play can be up to 16 steps long. Each "step" can be either "-" (both LEDs off), "R" (red LED on), "G" (green LED on), or "B" (both LEDs on). You can also define whether the pattern will only execute once or loop and play indefinitely. Additionally, you can make the pattern play at normal, double, or quadruple speed.

You load the new pattern to play with the pat.play method. If the pattern is looped, it will continue playing until you change it. If the pattern is not looped, it will play once and then the on_pat event will be generated. When the event handler is entered, the pat.channel property will be automatically set to the channel number for which the event was generated.

LED patterns offer a convenient way to tell the user what your system is doing. You can devise different patterns for different states of your device.

Here is a simple example in which we keep the green LED on at all times, except when the button is pressed, after which the green LED is turned off and the red LED blinks three times fast. Additionally, both green and red LEDs blink four times on startup. In this example we work on channel 0:

Sub On_sys_init

   pat.channel=0 'not really necessary since 0 is the default value for this property   

   pat.play("B-B-B-B-",PL_PAT_CANINT)

End Sub

Sub On_button_pressed

   pat.play("*R-R-R-",PL_PAT_CANINT)

End Sub

Sub On_pat

      If pat.channel=0 Then 'not really necessary since we are not using any other channels

      pat.play("~G",PL_PAT_CANINT)

   End If

End Sub

In the above example, the power-up pattern is loaded inside the on_sys_init event handler. This is not a looped pattern, so once it finishes playing, the on_pat event is generated and the "permanent" pattern "green LED on" is loaded inside this event's handler. This new pattern is looped (notice "~"). When the button is pressed, a fast pattern (notice "*") is loaded. This one makes the red LED blink three times. Again, this is not a looped pattern, so after it finishes playing, the on_pat event is generated and the "permanent green" pattern is loaded again.