Task
Tom is annoyed. His brother always helps himself to his candy – without asking for permission. This is why Tom wants to use Calliope to program an alarm for his candy box. Every time the box is closed the Calliope display is supposed to display a red lock. The LED below the display should light green. When opening the box he wants an alarm to sound and the LED to light up red.
Solution hint
The candy safe works by opening and closing a circuit.
Setup: A small piece of aluminum foil has to be attached to the lid and the body of the box. Now you need two crocodile clamps. One connects the aluminum piece on the lid with the upper left corner of the Calliope mini (negative pole). The other one connects the aluminum attached to the body with another pin of the Calliope (in this case pin 0). Tip: If you don’t have a cardboard box you can also turn the Calliope box into a candy safe.
Programming: When the box is closed and both aluminum pieces touch each other the circuit is closed. Calliope receives the signal “Pin is pressed”, shows the lock on its display and the lights the LED green. When the box is opened the aluminum pieces lose their contact, the circuit is interrupted, and Calliope executes all commands noted in “else” (Play tone and set LED to red).
Program code
Extension options for this challenge
- Sound variations (type, pitch, duration) and display screen
- Integration of a variable counting the number of times the candy safe is opened
- Mechanism to reset the counter
- Theft notification to a second Calliope using radio (that Calliope has to be nearby to ensure the transmission of the signal)
A visual demonstration can be found on YouTube.
Task
The Forest School has had a new break room for some time now. All students like the room but complain about it being full all the time. Principal Miller wants to find out how many people are actually using the room. That is why he wants to program an automatic counting station using Calliope mini. All students entering the room have to stand on marked fields with both feet. This is how they are counted. As soon as the Calliope LED flashes green, a tone is played, and a new number shows up on the screen they are allowed to enter the room.
Solution hint
The counting station works by opening and closing a circuit. As soon as an entering student stands on the counting mat covered with aluminum foil (usually works with bare feet or socks, rarely with shoes) Calliope receives the signal that the circuit is closed.
Setup: Two strips of aluminum foil are attached to a piece of cardboard. Now you need two crocodile clamps. One clamp is attached to connect one aluminum strip with the upper left corner of the Calliope mini (negative pole). The other crocodile clamp connects the other aluminum strip with another pin (in this case pin 0). Tip: The aluminum strips shouldn’t touch each other (liquid glue can have an impact on the conductivity!)
Programming
When a student stands on both aluminum strips the circuit is closed. Calliope receives the signal “pin is pressed” and increases a prepared variable called “counter” by 1. You should include a break to prevent the counter increasing in case the student doesn’t leave the mat quickly enough.
Program code
Extension options for this challenge
- Integration of a maximum: as soon as the predefined number of students is exceeded, an alarm sounds and Calliope stops counting.
- The pitch changes after each student entering the room to indicate when the maximum number of students is reached.
- The number of students in the room is sent to the principal using radio.
A visual demonstration can be found on YouTube.
Task
Mrs. Smith wants to award the grades for oral participation soon. It’s important for her to know how often each student raises his or her hand, but keeping a tally chart is too complicated for her. She wants each child to wear a Calliope wristband that automatically counts how often he or she raises his or her hand. Each time a student raises his or her hand the green LED flashes, a tone sounds and the number of times the hand was raised appears in the display.
Solution hint
The cooperation barometer is using the position sensor. Every time the position changes so that the logo is on top Calliope counts +1. For this you need a variable, in this case called counter.
Setup: Attach the Calliope mini to the student’s wrist with the enclosed rubber band (or masking tape). Programming: Every time the logo is on top the counter increases by 1 and chimes a sound to indicate it counted the raised hand (feedback), in this case a tone and a change of the LED color.
Program code
Extension options for this challenge
- Integration of a minimum: if a predefined number of messages is not reached within a certain time, a warning signal sounds.
- If a certain number of raises is detected a special signal is shown or chimes as an award
- The number of raises can be transmitted to the teacher using radio
- The pitch changes with each time the hand is raised and indicates how alert the student was
A visual demonstration can be found on YouTube.
Task
Joanna is annoyed. Her parents keep bursting into her room without knocking. That is why she wants to build an alarm system with Calliope that plays a tone every time someone is standing in front of her door and wants to come in. As long as no one is close a happy smiley should show on the LED display and the LED should light green. As soon as someone is approaching the smiley should frown, the LED should light red and a warning tone should sound.
Solution hint
The alarm system uses the light sensor. As soon as a shadow falls on the door and thus on the Calliope and a certain light intensity is undercut, the Calliope gives an alarm.
Setup: The Calliope is attached to the door using masking tape (which you can always remove). Be careful with the weight of the batteries, make sure to stick them to the door properly.
Programming: Every time a certain light intensity is undercut the alarm sounds. The threshold depends on the local lighting conditions and has to be tested.
Program code
Extension options for this challenge
- Variation of the alarm sound, the LED color and the LED display
- Integration of a variable which counts how often someone is standing in front of the door.
- Submission of a warning symbol to a second Calliope mini in the room using radio
A visual demonstration can be found on YouTube.
Task
Mrs. Smith enjoys giving her class tricky multiple-choice tests. Janine wants to create a cheating help that allows her to exchange the right answers with her best friend. When Janine clicks the respective button (A, B, A+B) Calliope should send the right answer (1,2 or 3) to her friend. As soon as the solution is submitted Janine’s Calliope should show a checkmark to make sure she knows the transfer was successful. To make sure they aren’t caught the solution should only be shown for 5 seconds (5000 ms) on Janine’s friend’s Calliope.
Solution hint
Calliopes can be connected with each other using radio as long as they are not too far from each other. Each Calliope needs the same code. Programming: At the beginning both Calliopes have to be added to the same group (in this case group 0) to make sure they recognize each other. Based on the pressed button (A, B, A+B) Calliope transmits the right answer (answer 1, 2 or 3). The respective number is shown and transmitted. The receiving device only has to show the received number and to delete it afterwards. It makes sense to integrate some kind of feedback (in this case a checkmark) that indicates when the number was transmitted.
Program code
A visual demonstration can be found on YouTube.
This text was published under a CC BY-SA 3.0 DE license. It was originally published in German popup: yes by erlebe IT popup: yes and translated into English by the Calliope team.