A saw a project in last months Make magazine which involved using an Arduino to display on a
16x16 LED panel. The article was "Long Distance Aloji Lamp" in Volume 83. It gave me an idea and I want to have some of my more advanced students work on it.
Keep in mind, I teach at a Middle School in an underperforming Title 1 (poverty) district. I am not being negative. That is just the reality that I am in. Less than 1 in a hundred of the students' at my school are even interested in the Arduino based class. However those, that are, are very interested.
My school uses an A, B, T, & O schedule. We alternate A & B schedule days, have state Testing schedule days, and, of course, the all encompassing Other schedule days.
What I want the students to make is a display that will have either an A, B, T, or O displayed in the hall outside of my classes. Yes, through labourious design, this could be done entirely in hardware. However, I want them to do it in software.
The initial design, in Make magazine, calls for all of the displays to talk to one another using
433mhz Arduino Boards. In that design, if one unit is changed, then all of the others change. As an example, if I were to change the unit in my classroom, it would change the unit in the hallway.
Not wanting the chaos of students regularly changing the display, I want the students to alter the design in the magazine to place a single transmitter on my desk, and the displays to have receive only functionality. I don't see this as being particularly hard. I have already worked out the code to make this happen. Of course, the students will need to come up with their own.
Then came the sudden thought about legality. these boards transmit on either
915mhz or
433mhz.
Do I need to send my callsign and can someone else legally change the display, which would result in a radio emission to the displays?I can think of a way to do that, such as sending my callsign in a print command to a device without the ability to use that data. However, the data has been sent. . . does that meet the station identification requirements?
How are the Radio Control pilots meeting the station identification requirements?
The information mentions the ability to use packet control libraries, is there something that I am likely to find in those libraries (note, libraries refers to a "thing" in the C programming language)
Here is some information about the boards:
- Measures 2.0" x 0.9" x 0.3" (51mm x 23mm x 8mm) without headers soldered in
- Light as a (large?) feather - 5.8 grams
- ATSAMD21G18 @ 48MHz with 3.3V logic/power
- No EEPROM
- 3.3V regulator with 500mA peak current output
- USB native support, comes with USB bootloader and serial port debugging
- You also get tons of pins - 20 GPIO pins
- Hardware Serial, hardware I2C, hardware SPI support
- 8 x PWM pins
- 10 x analog inputs
- 1 x analog output
- Built in 100mA lipoly charger with charging status indicator LED
- Pin #13 red LED for general purpose blinking
- Power/enable pin
- 4 mounting holes
- Reset button
- SX127x LoRa® based module with SPI interface
- Packet radio with ready-to-go Arduino libraries
- Uses the license-free ISM bands (ITU "Europe" @ 433MHz and ITU "Americas" @ 900MHz)
- +5 to +20 dBm up to 100 mW Power Output Capability (power output selectable in software)
- ~300uA during full sleep, ~120mA peak during +20dBm transmit, ~40mA during active radio listening.
- Simple wire antenna or spot for uFL connector