Reading the Digital Computer Electronics eBook (third edition):
Today we have heard about a new accident involving a teenager electrocuted by her mobile phone. Luckily, this time it was not a lethal case, but a quick search on the web has revealed that this is no joke: several teens have died in just a few years because they were either holding their phone with wet hands while the phone was being charged at the same time, or dropped their phone into the bath tub while the phone was plugged in, or because they were using wired headphones while charging their phone!
At first Simon and I didn’t believe this could be so dangerous, as he knew for sure that a mobile phone adaptor always has a voltage control built into it that reduces the voltage from 220V to something like 5 to 20V. But then we dove into it and found out that apparently, once a short circuit occurs, the adaptor’s voltage control unit also malfunctions and lets the 220V current through!
As some of you may know, Simon is working on building a real-life 8-bit computer from scratch, guided by Ben Eater’s tutorials (it’s a huge project that may takes months). He has also been enchanted by the idea to build the computer in a simulator as well, researching all virtual environments possible. The best simulator Simon has tried so far has been Circuitverse.org, although he did stumble upon a stack overflow error once, approximately half-way through (maybe the memory wasn’t big enough for such an elaborate circuit, Simon said). You can view Simon’s projects on Circuitverse here: https://circuitverse.org/users/7241
Link to the project that ended up having a stack overflow: https://circuitverse.org/users/7241/projects/21712
And here is a link to Simon’s new and more successful attempt to put together a SAP-1 (simple as possible) processor (work in progress), something he has been reading about in his new favourite book, the Digital Computer Electronics eBook (third edition): https://circuitverse.org/users/7241/projects/22541
Simon has also tried building an 8-bit computer in Simulator.io, but it was really difficult and time consuming:
The next hopeful candidate was the Virtual Breadboard desktop app for pc. Simon downloaded it about ten times from the Microsoft store but it somehow never arrived, most probably because our Windows version was slightly outdated but who knows.
And finally, Simon has also discovered Fritzing.org, an environment for creating your own pcbs with a real-life look. He may attempt actually making a hardcopy SAP-1 via Fritzing after he’s done with the Ben Eater project. Conclusion: sticking with Circuitverse for the time being.
Last week Simon suddenly unpacked his old electronics sets and completed several projects with Arduino, his old single-board friend that got him into coding a little over a year ago. Back then it was the most difficult stuff he had ever tried, his first “setups”and “draws”, his first dive into serious circuits. Now Arduino (and iCircuit) is something he does while taking breaks from the real studying/ coding. Amazing how skillful he has become in assembling the circuits, too. All those little wires. Especially considering he still isn’t an expert at tying his shoelaces.
Simon has discovered that every piano key on the electric piano corresponds to a certain voltage/ amount of energy/ electricity. He found this out by playing with his electric piano and the LittleBits, attaching various bits to the piano through a midi cable.
The lower the tune the lower the voltage on the number bit!
Simon was up to a new challenge and spent the whole day building circuits. Even during his Chinese lesson. We managed to finish 5 projects today:
Breezy Buddy (a fan)
Rotolamp (a disco lamp with a remote control to change it’s spinning speed)
Simon was doing most of the work himself (reading the instructions in English, assembling the circuits, pressing them on motherboards). The pressing bit required some help sometimes as well as securing the wires with tape. I made the paper templates, which Neva helped decorate.
She also made this cute evening video of the Rotolamp herself (she is singing a Russian lullaby, with modified lyrics):