HackerBox #0018 – Circuit Circus

Nick Momrik1 Comment

It’s not often an online ad catches my eye, but when I saw one for HackerBoxes, I clicked through. I’ve enjoyed Adafruit’s quarterly subscription service AdaBox and wondered if this was similar.

The HackerBoxes look lower quality, but are cheaper ($44 compared to $60, both with free shipping) and ship monthly instead of quarterly. The previous boxes listed on the site looked neat and sell for $59 before shipping so it seemed like a pretty good deal. I really like the idea of having something new to tinker with each month instead of only 4 times a year. I signed up and was surprised to get a shipment notification for the most recent box.

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This box is based around a little Transistor Tester kit you build. It also comes with a variety of extra electronic components that help go through a series of tutorials and aid in experimenting with circuits and the tester. If this box is any indication, I’m going to enjoy these each month.

It took me a couple of hours to assemble and solder the tester kit. I recorded it (had to stop twice to recharge the GoPro battery) and ended up with over 100 minutes of video! Nobody wants to watch all of that, so I cut out some empty space and sped it up to 20x.

Now I have a cool test device built by hand…

Link Dump – 2017/05/17

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Going to Bulgaria

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Heading to Sofia, the capital of Bulgaria, for a team meetup. It’ll beat out Budapest, Hungary as the farthest east I’ve traveled.

There is a 7 hour time difference from the Eastern time zone, so it’ll be interesting to see how jet lag affects me. Since it’s a +1 day trip, I won’t be going to bed (maybe a nap or two on the flight across the pond) until Wednesday night local time. Usually staying up through the travel night and all of the next day helps to reset my internal clock.

Phone Keypad Hacking: Part 3

Nick Momrik2 Comments

In parts 1 and 2, I walked through my journey of repurposing the keypad out of a phone from 1980. I learned that a more modern keypad matrix doesn’t exactly function (behind the scenes) in a way I’d expect. I wanted to understand it better so I set out to recreate a 2×2 keypad (kept it simple to make wiring easier) that would function the same way as something you can buy today. It would be a success if it worked with the Arduino Keypad Library.

adafruit-3x4-keypad

From my earlier looks through the code I knew it pulsed power out to a column pin and then read in each row’s key from that column before switching to the next column and repeating the process. I figured that should be enough for me to wire this up and try example programs without going back to look at the library’s code again.

I don’t know why I was thinking this would be more complicated and at least a little more exciting, but it was unbelievably easy. I guess I should be celebrating I understood how it worked. Literally all you do is connect one side of every button in a column to a pin and one side of every button in a row to a pin. No need for connections to power, or ground. No pull up/down resistors.

2x2-keypad-matrix-wiring.png

It immediately worked with the Arduino Keypad library examples, even the MultiKey one. I guess being able to detect multiple key presses at once is where the advantage to this implementation comes in. It worked flawlessly when pressing 2 of the 4 buttons, but when you get to 3/4 there are too many connections to distinguish the keys.

Just to be sure I had it figured out, I added a 3rd column to make it a 2×3 grid and it was just as easy.

2x3-keypad-matrix-wiring.png

I love the beauty of how simple this is. I’ve added Fritzing for both of these to my phone-keypad GitHub repo (2×2 & 2×3). If you check this PDF, in the How it Works section it has a really good explanation and shows the row and column connections exactly like I came up with.

Naturally now I need to do a part 4 and attempt to recreate the keypad implementation I ended up with from the old phone. Due to how it mechanically makes the electrical connections I think it’s going to be a bit more complicated than this was. We shall see…

Update: Read part 4.

The OA…The End

Nick Momrik5 Comments

I’d been limiting myself to no more than one episode of The OA per night, which has allowed me to enjoy each episode more I think. Last night I was watching episode 8 and then all of a sudden, season 1 is over. What the fuck just happened?!

I hadn’t looked at the episode list, but was fully expecting 5 more episodes, which is typical for a lot of Netflix shows. Even towards the end of #8 I didn’t expect the end was coming. So much shit happened in that episode and now I have so many questions.

I’m hoping there was already a good plan for season 2 because the sudden end completely threw me off guard and it feels like a rush job.