Re: How about an ultra-portable "QCX mini" version? #qcx


Hi Mike:

We're probably about the same age (I've been licensed since 1954) and suffer the same issues when building anything any more. Still, I've learned to enjoy SMD parts and find them probably a little easier to use. Videos like yours need to be more widely distributed so people can see how easy it really is to use SMD components.

As to Hans and the QCX, he doesn't use the Arduino Nano. Instead, he uses the "raw" Atmel 328 chip, thus avoiding the resources sucked up by the bootloader. That's why you have to use something like Arvdude to program a fresh chip or upload a new version of the software. Last time I spoke with Hans, he has something like 9 bytes left. I've done a fair amount of programming myself, but what he's packed into those 32Kb's is nothing short of amazing. He is well aware of the limitations of the 328, and the QSX will house an STM32F4 series chip which has a lot more resources and a faster clock. Like everyone else, I can't wait to get my hands on it. (Right now I'm talking to my QCX via CAT using a Teensy T4...I have some serious plans for it!) If you want to dink around with the code, I know of a beginning C book I can recommend...

There would be some advantages to having a "semi-kit" like the µBITX, as some of the support questions Hans has to field would likely disappear. I can see pro and con for each approach. We'll see what happens. Anyway, good work on the video!

Jack, W8TEE

On Sunday, June 7, 2020, 9:15:59 AM EDT, Michael Lloyd <mikell@...> wrote:

When I was almost 59 I decided that it was time to learn to solder SMD's. It made perfect sense to wait that long. I can't see as well as I used to. My hands aren't as steady. But! I am grandkid trained. I have lots more patience (cough). I stopped aging when I turned 6D. I am now 6D2. The alphabet age is wonderful :)

When I finished my first (very simple) project I wrote a beginners guide to soldering SMD components and put a (somewhat tongue in cheek but not completely) post on the EEVBlog forum. 


There were some pretty good additions and one flame war that I never did figure out what tripped their trigger, but I didn't try very hard either, in the responses.

I have a reflow oven that I bought off of eBay. It's fine for populating a group of boards but I rarely do that. Besides that, you have the added step of putting solder paste on the board. Solder paste expires, I never mastered using a stencil, and you still have to place the component by hand if you don't have the dinero or desire to own a pick and place machine. No more than I work with SMD I think hand soldering is fine. I can solder 0204 components with my microscope. That said, I don't "like" to solder 0204 components. I will sometimes use hot air and paste. Sometimes I use paste on one or two pins and the soldering iron to tack it in place. The paste seems to anchor the part in the spatial dimensions I can work in.

I read the discussion about Nano's, Arduino's, Microchip, etc. One of the common comments I see from Hans is how little room there is left for code changes. The Arduino bootloader uses some of the limited memory on the ATMega chip that he uses. That doesn't bother a no-talent coder like me, it makes it easier for me to blink an LED, but I think it would make the QCX, as we know it, unlikely to have come to be.

I defer to Han's experience with mass producing boards. I wouldn't mind doing the SMD soldering myself. At least I wouldn't as I type this. Check back with me after the last component flits off of my tweezers and flies off into whatever dimension Satan resides in :)  



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