UBW Play - Liberty Basic Program
For Firmware version D
General
This is an application for Firmware D. It allows each pin of a UBW
board (28 DIP or 28 SOIC) to be set to be an input or an output, and if
the pin is an output you can set the bit high or low. It also
constantly polls the UBW board to read every pin as an input and then
reflects those states with little green LEDs. There is a pull down list
to select the COM port that the UWB board is on - it is automatically
refresshed every 5 seconds.
This code would be a good place to start if you are going to make a
complex PC application for Firmware D, as it has some nice subroutines,
including sending O, I and C commands and the serial port handling
routines.
How It Works
The code works by watching for user clicks on the buttons, and
issuing an "I" command to the UBW board every timer tick. This prompts
the UBW board to issue a response "I" packet back to the PC with the
current state of every pin. When a button is clicked, the new state of
the pin is sent to the UBW board with a "C" packet (for changing
direction of the pins) or an "O" packet to change the output value of
the pin.
What's not in this version is the ability to recognize error bytes sent
back from the UBW as it's processing packets, and the ability to do A/D
readings.
One thing to note is that if you don't have the UBW connected to
anything (i.e. its pins are floating) and they are set to inputs then
the green LEDs will blink a lot as the PIC is reading the pins as
random noise. Also, C0 and C1 are connected to the yellow and red LEDs
respectively, and the default firmware D code slowly blinks C0 to
indicate that it is connected and talking to the PC, so you'll see the
LEDs on the PC reflect the state of the real LEDs.
Files
A Zip file of all necessary files
(basic source, LED bitmaps) - updated 2/23/09 to use example keypress
handling code
Browse the files
Code
The code is quite long, and includes many comments, so you can just
download the zip file above rather than scroll through the code here.
Questions? E-mail me at
