I thought back to the funnest buttons to play with on trips to Radio Shack as a kid and added three standard toggles, a covered illuminated toggle, a slider, and an arcade button, plus two modest momentary buttons. The USB A connector leads to a physical switch, which worked great (eventually). We used one that supplies power as soon as it detects a device connection. Be aware, though, that some power packs require the user to press a button to turn them on. Best of all, this works thematically! A four year old can see the current power level, and if it runs out in the middle of playtime, replacing the ship's fuel cell can easily become part of the adventure. It delivers the correct power and current, it's rechargeable and compact, and it includes its own charging circuitry and a level display. It was decided early on to power the dashboard with a USB power pack. We tried two different screens, and both suffered from a lack of documentation (I hate to criticize, as I appreciate the tons of work the developers did! But there were still some obstacles). We decided to connect the screen using the GPIO pins instead of the HDMI port because I thought it would reduce complexity, cost, and possibly power consumption, although in the end I don't know if it really did any of the three. We decided to use a 3.5" screen early on because it'd be hard to fit anything larger inside, and also because I wanted to be frugal with power consumption. The previous one had a 7" display connected using an HDMI-to-TFT board. This is the second Pi project I've done with a screen. It sacrifices three USB ports and the Ethernet port, but I think it's a great trade, not just for size but because I think it suffers less from the constant current shortage that plagues most of the recent Pis. It's got a built in WiFi module and a full size HDMI cable, but it has a smaller footprint than a traditional Pi. We ultimately went with a Raspberry Pi 3A, which remains my favorite Pi. We decided from the start to use a Raspberry Pi in order to be able to display content to a screen and to be able to receive videos over WiFi. Below is a Gantt chart that got thrown out when we had a mid-project burnout. I constructed a prototype on a breadboard while installing the necessary software and coding the programs to achieve the desired functionality. Then we could select parts and model the enclosure around them. Once we had a concept, the next step was to create a schematic that clarified what hardware components would need to fit into the enclosure. The following outline roughly follows my design process, minus all the trips back to the drawing board. Lastly, I decided to power it off a USB battery, accessible by opening a clear door panel covering the lower half of the housing. ![]() This offered the user the option of playing whatever the latest message was once it finished checking or skipping ahead to the main menu. ![]() I eventually added a second menu before this one because the device needed to first connect to Wi-Fi and check for new video messages and download them if available before the main program ran. ![]() I decided to dedicate one button to cycling between options and one button to executing the current selection. I decided I wanted it to boot into a menu that offered two options: one to display a dashboard on the screen and one that would display a list of video messages available for playing. Once I could visualize the form-factor and some buttons I had to decide what the user experience would be like. ![]() All it had was a calendar program, so my brother, sister, and I built a fort around it and scrolled through the calendar to travel though time in our imaginary time machine.Ĭonsidering how quickly kids' interests change, my goal was to imagine use cases a kid would enjoy while also making it flexible enough to be whatever they might imagine. I drew on fond memories playing with a Compaq Portable when I was a kid. I wanted the user to be able to hang the device over the edge of a cardboard box to make it feel like a part of a cardboard box vehicle. The goal was to produce a small, fun, user-friendly package that could be operated by a child. This took about 100 hrs and $150, but would be half of each if starting with what I know now. The outcome was - like most of my projects - a steaming pile of learning. Wouldn't it be especially cool if we could play with her from afar by sending video messages? So that's what we set out to make for her Hanukah present. My brother and I loved it, and discussed how cool it'd be if we sent her some kind of control panel of knobs and switches. This fall, my sister sent me a video of my 4-year-old niece, deep in the midst of her astronaut phase, showing off a cardboard spaceship for the assessment of her engineer uncles.
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