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Signed and encrypted email
It’s surprising that S/MIME is not more widely used. It offers authentication, so that you can be sure the email comes from the person that email address belongs to, which will kill all (spear-)...
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Garbage collection for JET
The JET project is based on a dataflow engine, which needs to run on a variety of hardware, in particular fairly low-end µCs.But dataflow requires passing messages around, and I want these messages to...
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Data structures for JET
Another post about the JET project. This time around, I’m trying to come up with simple data structures to get the job done, i.e. supporting a PureData-like dataflow engine, able to fit in very small...
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Data structures for JET, cont'd
I made some good progress on the design of an early prototype forlast week’sJET data structure design. So far, it’s all working out well (I’m coding this in C), with some useful refinements:the gadget...
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Winding down, switching gears
Let me get right to the point: the scheduled daily weekly posts on this JeeLabs weblog are coming to an end. I’m going to move away-and-onwards from the“blogosphere”.There are several reasons for this...
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JET today - there's a lot to do!
Sooo… with all this talk about Unicorns and Ambitions, it’s now time to walk the walk.I’m focusing my efforts on 3 repositories:JET is the over-arching collection where all the pieces of JET come...
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SMA Solar readout - part 1
This is the first post of a 3-part series about reading out an SMA solar inverter over Bluetooth and displaying some readings every few seconds. Long-time readers may remember the Solar at last weblog...
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SMA Solar readout - part 2
(Part 2 of the SMA Solar readout series)Here is the hardware, with its three main components - LCD, µC, and Bluetooth:The bottom is wired up using my favourite one-off soldered-kynar-wire technique:The...
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SMA Solar readout - part 3
(Part 3 of the SMA Solar readout series)With everything working as intended, it’s time to wrap things up. As this unit only has an LCD sticking out and no other controls (i.e. It Should Just Work when...
View ArticleTFoC - A minimal computer
(This article is part of the The Fabric of Computing series: in search of simplicity)With today’s programming languages, it’s easy to ignore what goes on inside. Maybe you’ve never even bothered to...
View ArticleTFoC - A compiler in 256 LoC
(This article is part of the The Fabric of Computing series: in search of simplicity)The previous TFoC post was about a truly minimal setup, capable of just very simple computation. This time, let’s go...
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Winding down, switching gears
Let me get right to the point: the scheduled daily weekly posts on this JeeLabs weblog are coming to an end. I’m going to move away-and-onwards from the “blogosphere”.There are several reasons for this...
View ArticleLooking for something?
function search(elt) { elt.q.value=“site:jeelabs.org “+elt.s.value } This is a list of “stuff” I’ve worked on over the years, in reverse chronological order: This site has changed shape a few times,...
View ArticleHello again, world
After nearly a year of silence, I’ve started writing articles again. Much has happened, but I’m still delighted by the sight of a tiny blinking LED and the smell of a good solder joint. New look, same...
View ArticleHardware CRC calculation
Most (all?) STM32 microcontrollers have a built-in hardware checksum calculation unit. From Wikipedia: A cyclic redundancy check (CRC) is an error-detecting code commonly used in digital networks and...
View ArticleRandom numbers in hardware
Random numbers are useful for simulations, to create a sense of arbitrariness in games that might make them more “interesting”, i.e. generally speaking: to introduce a level of unpredicatability in the...
View ArticleToggling I/O pins on STM32
All microcontrollers have I/O pins to connect to the outside world. These can be used as inputs or outputs, and tend to have various interesting capabilities. Here, I’ll treat these “General Purpose...
View ArticleGetting started with the Blue Pill
The “Blue Pill” is a small development board with an STM32F103 32-bit ARM µC on it, plus essential supporting logic. It’s widely available and very low-cost. See this wiki page on the STM32duino...
View ArticleTurning a Blue Pill into a Z80
The Z80 micrcomputer was a revolutionary chip in the 1970’s - a more capable alternative to the Intel 8080. The commercially smart move was that it implemented (almost exactly) the same instruction set...
View ArticleSTM32F103 low-power mode
I’ve always kept an interest in low-power explorations, most of which I did many years ago. First there was the ATmega328, then the LPC824, and finally on the STM32L052. One reason, is that I find it...
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