After the hardware to feed yesterday’s scrolling LED display, comes the software:
The code has also been added to GitHub as tickerLed.ino sketch.
Fairly basic stuff. I decided to simply pass incoming messages as is, but to do the checksum calculation and start/end marker wrapping locally in the sketch. The main trick is to use a large circular 1500-character FIFO buffer, so that we don’t bump into overrun issues. The other thing this sketch does is throttling, to give the unit time to collect a message and process it.
Here’s what the display shows after power-up, now that the JeeNode is feeding it directly:
(that’s the last part of the “Hello from JeeLabs” startup message built into the sketch)
So now, sending a 50-byte packet to node 17 group 4 over wireless with this text:
<L1><PA><FE><MA><WC><FE>Yet another beautiful day!
… will update line 1 on page A and make the text appear. The unit rotates all the messages, and can do all sorts of funky stuff with transitions, pages, and time schedules – that’s what all the brackets and codes are about.
Time to put the end caps on and close the unit!
Why do I now have a mental image of the display mounted in JC’s “play room” with a message saying:
“Dinner is ready!”
?
:o)