As the project is already close to being finished, and I basically used Github's README.md to record my progress, I am writing this page on Hackaday.io as a way to 'release' the device, and as a way to get feedback on it.

This was a project that I did for myself, to prove I could do it and to learn, and so I did.

I set out with a list of requirements, which I carefully curated. And I was determined to implement no less, but also no more of those requirements. The reason being that I have many unfinished projects, and many of those projects are unfinished because I set either unrealistic requirements, or ended up spending much time on feature creep instead of taking time to finish off something that was well rounded and not tied together with strings.

• The nTerm2-S would be basically using Fabrizio's FabGL library, and should be fully compatible with it. The objective being to run Fabrizio's excellent ANSI terminal example.
• It should be small, made with SMD components, and still be hand-solderable. The objective being to learn to use Kicad and make PCBs through JLCPCB or the like.
• It should feature a real RS-232/V24 port, meaning that it should be able to communicate RS-232 with +/-12V (or so).
• It should feature an on-board amplifier so I could simply connect a speaker.
• It should feature a way to, in software, switch between normal communications and null-modem.

I more or less succeeded in all of that, and come to a rounded, finished, project, which I am proud of. :)

But still, I had missed one important requirement that I want to name here.

• It should have an on-board RTC with battery backup.

In this blog, I'll highlight a few of the most interesting challenges I had, in the hopes that it is a bit educational. Also, I am thinking of making a new version with more or less the same requirements, but using HDMI. And I'd really like to hear some feedback too.

You can read all the details (really, there are a lot, I like to write ;)) of my development process on the corresponding Github pages.

• nTerm2-S
• nTerm2-S-FT231
• SporosTerm

One thing I want to clarify up front is why there are 2 versions of nTerm2-S: nTerm2-S and nTerm2-S-FT231.

I started out designing the nTerm2-S using a CP2102 USB to Serial bridge IC. It is a great IC, supported out-of-the-box by all major Operating Systems without having to install any drivers. I love it, and it was working great in the nTerm2-S. However... When I made my first prototype, I found that it's really hard to hand-solder reliably. I had to resort to hot air and a lot of fiddling to get it properly soldered down. I thought it might be me, having a bit of shaky hands. But with my second prototype it was all the same misery. So after long deliberation, I decided to switch to a different USB to Serial bridge. After careful looking around, I found the FT231, basically archived the nTerm2-S with CP2102, and made a new Github project nTerm2-S-FT231. And that is the version that I brought to completion.