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.
What a great story! It is very cool to see that Jeremy's older daughter drove the project with her idea to have the mailbox open by using a sensor to trigger it. Dad had a great opportunity to have some awesome family time with his daughters while stimulating in them a desire to learn about electronics. What a great combination! And the cuteness factor is off the charts!
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.
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!
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!
Wow! So what I'm thinking is back in the "olden days," kids were much more handy with natural raw materials, and now they are much more handy with technology. Not sure what happened to my generation! (Though truth be told, some of the kids were really good with electronics at the time; I am just wasn't born with the mechanical or builder gene. :))
"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!"
Elizabet, School projects and student's interests are different. In schools they used to do the projects with thermo cool sheets and similar substances, but at the other hand they are more interested in using most soficated devices.
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.
Nancy & William - To a young person without much understanding of electronics, using a modern microcontroller can be much more, um, plug-and-play. In the course of interfacing the servo and the light sensor, they still have an opportunity to discuss and learn some very basic electronics, enough to potentially spark an interest in hardware OR software OR (my favorite) BOTH!
I'm excited about today's technical environment and the renewed and improved accessibility of both electronics and software to a young hobbyist. Just 15 or so years ago I was lamenting the impending fall of electronics as a hobby (or gateway drug ;) for youngsters. I'd cite things like the prevalence of surface mount components, lack of accessible/affordable tools for circuit design, layout and software development. I am so glad that I turned out to be very wrong! Instead, microcontrollers like the AVR and PIC have become easier to use, boards like the Arduino are affordable, easy to get started with and, to be able to do much more than blink an LED or move a servo, they actually encourage electronics tinkering. Scmartboards for surface mount parts and micros still available in thru hole packages mean you don't need a pick and place machine in your bedroom ;)
Heck, even Radio Shack is back to stocking things for real hobby electronics!
I agree Rathomas - the accessibility and affordability is very exciting. Not only Radio Shack - but being able to order development kits off of the internet at reasonable prices is very nice. I just bought hubby a PIC student development kit for his birthday - it is way cool - I think I will be playing with it too!
This story is going to be a big help to me at home. My mailbox is on the street about 150 feet from my house, and with the various letter carriers comming at different times, me and my lazy butt hate walking to the box and finding it empty. For years I've been complentating a mechanial device with a torsion spring to stand up the red flag when the letter carrier opens the front door. A suitable trigger arrangement would obviously work, but I was afraid that the shock of the flag popping up would scare the mail person resulting in some sort of liability on my part. With a small motor slowly erecting the flag, there should be nothing to scare him. Yes, I know the red flag is supposed to indicate that outgoing mail is in the box to be picked up. I wonder if there's a Postal Service rule on this matter?
You'll still probably freak out your mail carrier, Bob. If it was me and I saw a flag moving upward on its own - I would definitely be curious, if not concerned. I would love to see the expression on their face! And their schedules change in our neighborhood so you may have the opportunity to startle multiple carriers. Unfortunately since the Postal Service is a federal agency with a multitude of rules and regs, they may not appreciate you assigning a different job to their flag...
I agree with Nancy--the mail carrier will likely freak out, not only from curiosity, but from concern if not downright fear. Instead of making the red flag go up on the box, why not just install some motion sensing or other devices like some country people use for being notified that someone's at the gate at the end of a long driveway, or that bears are raiding the orchard? You get an audio signal inside your house, alarming no one but you.
Great brainstorming, Ann and a practical solution to the problem - just the kind of thing that what would happen if we moved forward with that forum we were talking about ;) I don't believe an NDA is required either LOL
Thanks, Nancy. I actually knew people in a remote area of Idaho where bears get into the orchard and with a very long driveway--that's where I first heard of these systems. And we'll be posting an update soon about the forum idea.
I agree, mrdon. Our family had a great time together when we encouraged and mentored our son through his science project where he tested out various fin designs and their effect on model rockets. He was in sixth grade and it was a very special opportunity to nurture a budding curiosity in science in a fun and exciting way. We took the three different models our son built to a field and he recorded altitude and flightpath for each of the three different fin designs. I don't know who had more fun - Son or Mom and Dad!
Bob, I think you are on the right track with a mechanical solution. A web site called themailsig dot com shows a red ball on a chain that falls when someone opens the mail box. After falling it hangs about 12 inches below the box so you can see it from the house. Probably cheaper than a torsion spring and postmaster approved according to the site. Plus you get to make cracks about "the old ball and chain"!
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.
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.
This is just, well, cute as heck. I remember the cardboard versions of Valentine's mailboxes from elementary school, and these actually resemble those a lot except for the materials, and obviously the electronics. What a dad!
As father of precocious 6 and 2 year olds, I recognize how my perspective has changed in the past, say, 6 years.
In olden tymes, my reaction probably would've been. Yeah, neat lid.
Nowadays, my response goes like this:
daughter gets an idea to make something
... and takes initiative to do something
... and solicits Dad's assist
... and Dad steps up to the plate
... and little sister gets involved
... and Mom gets involved to take the idea from an animated shoebox (yes, I'm intentionally being disparaging here, albeit in a light-hearted way) and shepherd it into a product with immediate appeal outside the gearhead community.
This is a Truly Great Family Thing that needs to be savored and put in the scrapbook.
I guess your kids are a little old for this, so you'll have to modify appropriately, but I'd say:
Kudos to the whole family, and Happy Meals all around for Saturday dinner.
p.s. Jeremy: some hombre-a-hombre advice, I don't recommend showing this article to your Better Half until you do some revisionist editing and give full productization credit appropriately. I'll go out on a sexist limb here, but with this whole "family" thing, women eat this shtuff up. Know what I mean? (nudge nudge: You might have some more dividends to harvest, even if they would only be as "Keep Jeremy out of the Doghouse" insurance.)
Now this is one cool story. I love the interaction with everyone in the family AND the fact that a great demonstration of engineering, at it best, was given. I'm sure your daughter will remember this "gadget" for years and years and I suspect it will be one of her most treasured items as she grows up. Bridges, automobles, appliances, aircraft engines is what we do for a livig--designs like this one is what we do for our families. Great post. Love this one.
I, too, like the family aspect of this story. I also agree that this girl will remember this project for many, many years (especially since the project got a little bit of extra publicity). Who knows? Maybe this will inspire her to be a design engineer.
Jeremy, I really enjoyed your Gadget Freak project. Nice way to share tech as family by making cool interactive toys! I also found your build instructions to be clear and simple. I noticed you used ExpressPCB software to draw the circuit schematic diagram. Very very nice project. Thanks for sharing this special Gadget Freak project with us!
The final showdown is under way in our first-ever Gadget Freak of the Year contest. Who will win an all-expenses-paid trip to the Pacific Design & Manufacturing Show? It's up to you, dear readers, to tell us.
For industrial control applications, or even a simple assembly line, that machine can go almost 24/7 without a break. But what happens when the task is a little more complex? That’s where the “smart” machine would come in. The smart machine is one that has some simple (or complex in some cases) processing capability to be able to adapt to changing conditions. Such machines are suited for a host of applications, including automotive, aerospace, defense, medical, computers and electronics, telecommunications, consumer goods, and so on. This discussion will examine what’s possible with smart machines, and what tradeoffs need to be made to implement such a solution.