Using BBC BASIC for Windows
with the
Velleman K8055 and K8061 USB Interface Boards
I
bought a Velleman interface board some time ago and
found that there is a
distinct lack of code examples on the web, particularly in a nice
little language like BBC BASIC for Windows. BBC BASIC is ideal for
this task as it is an interpreted language and as soon as a line of
code is written, it can be run and tested on the fly. All the programs
run in their own window and hence your computer stays multi-tasking at
all times.
Here are a
few simple programs and projects for anyone interested in these
things to play with. The overall idea is to make things as simple and as
basic as
possible, so I have attempted no fancy programming or showing off
whatever. All variable names are as descriptive as possible, to make
understanding a bit easier. However, don't expect massive amounts of
explanatory REM statements. I am an indifferent typist and lazy to boot!
I give
suggested circuit boards layouts, but as many components vary so
widely, some of this will be of limited use. Also, I like to etch my own
circuit boards and I fully realise that this is a minority sport. Feel free
to contact
me if you think I might be able to help.
 Here
is a little trick which others may find useful. The ADC input of the
board can be amplified by adding resistors R8 and R9 (R53 and R54 in the
new K8055N). Velleman
explains it in the leaflet. Rather than unsolder and resolder these
components frequently, I fitted two link posts and soldered the desired
resistor to two links. This enables me to fit any resistor of choice as
easily as I can remove it when not wanted. A 3k3 resistor link is
shown below and in place on the left. You can work out the
resistor for any required gain (within reason) by using the formula
Gain=1+(10k/Rx)
I found this little trick quite useful.
The K8061 is a new addition to my collection and there
is a page about it via the link below.
Most of the programs written for the projects below also come with code for the K8061.
Some links
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