It’s always a good day when you get a package from the fab. There’s something simultaneously exciting and daunting about unwrapping a shiny new batch of PCBs. On the one hand, there are the possibilities promised by the new device. On the other, you’re wondering whether you made some kind of mistake in the design and if the thing will… Read more »
In an earlier post, I described how I can now load software on to the Zolatron 64 6502 homebrew computer. The LOAD command was pretty basic – you couldn’t specify a file. Instead it just loaded the same file (zd.bin) which I’d have to overwrite if I wanted to load different code. Well, those days are over, and the Zolatron… Read more »
In a previous post, I detailed how I’m having to shift voltage levels on signals running between a 65C22 VIA chip and the GPIO pins of a Raspberry Pi. The solution I settled on was to go for simple voltage dividers using pairs of resistors. And that’s been working fine. I mean, you’d expect it to work with the 5V… Read more »
As I mentioned before, the Zolatron 64 6502-based homebrew computer (Z64) needs some kind of persistent storage. And these days there is no shortage of options. If you search around the interwebz for homebrew projects you’ll discover a treasure trove of clever solutions. But many of these involve implementing some form of existing technology. For example, you can employ a… Read more »
Pretty much every computer needs persistent storage. And these days we’re spoiled for choice – everything from hard drives down to micro SD cards being capable of holding more information than I can comfortably imagine. With clever interfaces, these options are also open to builders of homebrew computers, like the 6502-based Zolatron 64 (Z64). But it does mean grappling with… Read more »
Well, it had to happen sometime. I finally killed a Raspberry Pi. Not on purpose, of course. I’m not a psycho. (I’ve been tested.). Nope, it was just sheer impatience and stupidity. But we’ll get to that in due course. First, let’s talk about finishing a project that was already finished. Just when you think you’re out… Sometimes you think… Read more »
It’s always a good idea to know the state of the machines on your network. Plus, I’m a geek, and messing around with data appeals to me. One metric I especially like to keep an eye on is CPU temperature. Why? Why not? I’ve recently got into InfluxDB and Grafana, and that’s the way all future projects will be going…. Read more »
One of the problems with having just two people living in an old, rambling house is that you spend a lot of time shouting. My More Significant Other (MSO) and I work in different parts of the house – I have an office and she prefers to work on her laptop in the living room. We often need to communicate… Read more »
Well, it does seem that the problem I’ve been having with the SmartParallel board is indeed that horror of horrors – the intermittent fault. Or perhaps something weirder. This is some kind of quantum device – it works only when being observed. Setting up a server The SmartParallel was working perfectly for a few days. Then I didn’t use it… Read more »
Success! The Go code I’d been struggling with is working, although it also required changes to the C++ code running on the ATMEGA328PB. Here’s a quick overview of how the process works. On the SmartParallel, the ATMEGA328PB code sits in a loop watching for incoming data on the serial port. It also monitors the state of the printer by frequently… Read more »
The principle of ‘one step at a time’ is very sound. The more changes you make at once, the more places there are for bugs to hide. And that’s why this project has been progressing slowly – or not at all – just lately. Finally, though, I feel like it might be back on track. A quick recap: SmartParallel is… Read more »
I was pretty pleased with my serial level shifting board – right up to the point where I tried to use it. The tl;dr version of this post is that the board works, but not well enough. It has severe limitations that, I think, make it useless for the intended purpose. Let me explain… Voltage levels The purpose of the… Read more »
Not every device speaks the same voltage. In designing the SmartParallel serial-to-parallel printer adapter, I chose to use 5V as the VCC supply throughout the board. But I was constantly aware that some of the devices that might talk to the board – such as the Raspberry Pi – use 3.3V for their I/O. What to do? There’s only a… Read more »
Go – or Golang if you prefer – is a powerful programming language, applicable to virtually any platform, from single-board computers (SBCs) such as the Raspberry Pi to supercomputer clusters. I tend to work at the lower end of that scale. And I was motivated to check out Go because it has a reputation for being fast – unlike, say,… Read more »
You know you have a Raspberry Pi problem when you start searching around for projects just to use them up. But then, admitting you have a problem is the first step to recovery… PiHole? Check. PDP-8 (plus intranet server and MQTT broker)? Check. Alarm clock? Check. Retro radio thing? Work in progress. Dream machine? Also in progress. Dot matrix printer… Read more »