During the component shortage, I got to know Raspberry Pi’s RP2040 microcontroller. It is a dual-core Arm Cortex-M0+ with about 262 kilobytes of RAM. The feature I like most is the programmable IO pins. These are small state machines that run independently of the Arm cores. They allow for some clever tricks. For example, I used them extensively on the Mega IIe project.
Most of these pictures from the Mega IIe project did not make it into a video or talk. There were many “behind the scenes” style shots. Some of the pictures have titles and descriptions. I work on them when I have free time. Let me know your favorite!
These links accompany the Mega IIe presentation at Supercon 2023.
The Dayton Amateur Radio Association (DARA) hosted Hamvention 2023 in Xenia, Ohio, on the weekend of May 19th. This annual event is the largest gathering of amateur radio operators. Sprawled across the Greene County Fairgrounds and Expo Center are commercial vendors selling gear or services, educational talks, license exams, and a massive flea market.
Often I hear this question: “how can I get better solder joints?” Without looking at anything they are doing, I already know that they could be using more flux. Or, as I point out in this video, perhaps the correct type of flux!
Flux removes oxide layers, gets contaminants out of the way, and makes for better solder joints. But there are so many different types of flux and even more ways to apply it.
This video goes over the different types of Rosin (R, RA, RMA), Resin, Organic, and Inorganic flux. Then it shows what kind of residue gets left over. And explains why “NO Clean Flux” actually needs to be cleaned (in most cases).
What is No Clean Flux?
In the video, I make the bold statement that “no clean” is not a type of flux. I know some people will take issue with that. However, based on the IPC chart for flux bases, “no clean” is not one of them. And if you look through datasheets, you’ll find lots of variations of what manufacturers call “no clean.”
From what I can tell, “No Clean” flux is generally a Non-activated or mildly activated Rosin or Resin type. The remaining residue is non-conductive and non-corrosive. So by that general definition, many fluxes can be marketed as “No Clean.”
