system browser and take you right to the BlocklyProp
home page where you can log in.
Once back into the system, a menu across the top of
the page will allow you to view community projects,
select from one of your own projects, or create a new
one. We’ll start by creating a new project. A drop-down
menu will present Scribbler Robot and Propeller C. Select
You’ll be presented with a page where you can
describe the project and select the board that it runs on.
In my case, I’m using the Propeller Activity Board (PAB),
but I am going to select “Other” for board type (Figure 2).
Why? Because the “Other” board type doesn’t limit
access to blocks as some board types necessarily do. That
said, this comes from the added responsibility of knowing
my hardware. I do!
Click on the Next button and select Private. I think it’s
a good idea to keep my projects to myself until they are
fully wrung out and ready for others to work with.
BlocklyProp allows us to go back and make a project
public (Shared) when it’s ready to impress the world.
Finally, click on Finish. That big blank space that
consumes most of the screen is our programming work
space. On the left is a vertical menu with BlocklyProp
elements. Let’s start with the obligatory “Hello, World!”
blinking LED example, shall we?
Click on Control to get a fly-out menu of the various
control elements. As most programs contain an infinite
control loop, we will use the simple repeat block (third
from top); click on and drag this block to the canvas.
This block has a drop-down menu that is defaulted to
“forever.” For our master loop, that is what we want.
From the Communicate menu, select Terminal, and
then drag the Terminal print text block onto the canvas
and insert it into the repeat block. You’ll notice that the
terminal block contains a string variable that is preset to
“Hello.” Change this as you please.
The PAB has an LED connected to P26, so we’ll
make that blink. From the Pin states menu, select make
PIN. Oh, there are two. Note that one of these two
blocks has a drop-down menu to select the affected pin.
As I selected the “Other” board type, all pins are available
from this list. This will not be the case with some boards.
The second block contains a variable that defines the
pin to be used. In either case, drag the block onto the
canvas and connect to the bottom of the terminal block,
change the pin number to 26, and leave the state high.
With the LED on, we need a delay. In the Control
menu, there is a pause block. Drag this under the make
PIN block and set the time to 500 ms.
Right-click on the make PIN block and select
Duplicate. Drag this block under the pause block, and set
the state to low. Duplicate the pause block and drag it
under the second make PIN block. Leave the timing at
We’re done! The final program should look like Figure
3. Above the programming work space, you’ll see five
round icons; two are green and have downward-pointing
arrows. Select the arrow without a horizontal bar to
download to the Propeller RAM without overwriting the
EEPROM (that’s what the other icon does). When you do
this, you’ll see the programming status window pop up,
followed by the terminal that happily prints our message
as the LED blinks every second.
To be honest, it took me far longer to type and for
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July 2017 13
■ FIGURE 1. BlocklyProp client.
■ FIGURE 2. Project definition.
■ FIGURE 3.