At the elementary school my children attend, students exchange Valentine's Day cards with one another, and they compete to decorate or build the most interesting mailboxes. My 11-year-old daughter came home one afternoon with an idea for her mailbox. She asked me to help her design one so that a sensor would open the box automatically when someone walked by.
I started with a servo motor (and some mechanical linkages) taken from a broken remote controlled car, connected it to an Arduino UNO microcontroller development board, and connected a light sensor to one of the microcontroller's analog inputs. We wrote the code to monitor the sensor and track the average light level. The box would open only when the light level changed suddenly. Then the box would close slowly over a period of time.
We actually built two mailboxes, so my 8-year-old daughter could have one, too. My wife helped the girls decorate the boxes to look like their favorite animals. I used the Arduino software tools to create the firmware, and the Arduino board served as my MCU chip programmer. But I assembled the components, including the MCU chip, on a piece of perforated breadboard material, rather than using the Arduino UNO development board in the final project.
Jeremy Willden created small mailboxes for his daughters' Valentine's Day cards. The boxes use a sensor to open automatically when someone walks by.
Willden started with a servo motor and some mechanical linkages, which he connected to an Arduino UNO microcontroller development board. He then connected a light sensor to one of the microcontroller's analog inputs.
Elizabeth: When I was in grammar school, toothpicks had not yet been invented, but one of our teachers suggested that us boys build an American settler house. So, after school we went into the woods, chopped down some trees w/ our fathers' axes, and built a house. It was so well designed that the principal of the school moved his family into it!
what a lovely rainbow of responses to this application of excess from the cutesy to the crotchety. There are a galaxy of ways to build a jack in the box.
I had a comparable project when I started with an outdoor solar powered water pump that kept burning out because it was allowed to run dry.
By the time I'd come up with a circuit to detect water and protect the pump in the event of dry conditions, I had a 10 Ahr 6V lantern battery involved with all the overhead of weatherproofing that came with.
The final analysis was I really needed a thermal protection circuit on a 6Volt 80 mA, 1 foot lift 15 gal./hour submersible pump. Problem there was its operating temp. bordered on the seize temp.
Mind you, an $18 pump.
We bought more pumps and tried to pay closer attention to the water level.
Our 18 month-old great grandson came home from the office the other day, announcing that NASA had chosen him to write the code for the main booster ignition system for the new HEAVY-LIFT rocket which is going to propel some Argonauts to a distant galaxy. The chief software engineer at NASA said that our boy would have complete control over the project, and that he could choose any "efficient language" to program the system.
So!, being the smartie pants that he is, he's decided that he will program the code in ARAMAIC, which is a new language that he's been working on for about 3 weeks already. Before leaving his high chair after his mother gave him his afternoon bottle, he said that he would be retiring to his lab to finish work on the compiler. He expects ANSI to give it a final approval in about a week, at which time it will have received the formal certification, so it will be qualified under NASA administrative rules.
These two mailboxes are definitely neat! But why in the world waste time and effort using an Ardunio module to control them? A dual comparator chip and two transistors could simply duplicate the functions described, and do it with a lot less standby power consumption. Beside that, it would be a far more educational exercise.
Isn't that the truth, Mydesign?? I remember when my school project was to build an American settler house with toothpicks! We have come such a looooonnnng way from that. It's amazing how tech savvy kids are today. Sometimes a bit frightening, even!
These are great! And certainly more high tech than anything I ever did for Valentine's Day when I was a kid. What a creative and a wonderful way to teach your children about gadget-building while providing enjoyment at the same time.
In our third annual contest, Design News and Allied Electronics are going to crown a winner in early 2016 for the best reader gadget submission this year, and once again, you, the readers, are the judges!
The Attack Dyno brings car enthusiasts an attack timer and dynamometer in a small, portable package with the ability to output vehicle torque, speed, horsepower, 1/4 mile times, 0-60 mph acceleration times, ambient air temperature, and more.
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