Guess what? I realized that I had a bunch of microcontroller dev boards and such that I was probably never going to use, so I figured it would be time to put them up for sale, along with some other miscellaneous electronics stuff as well.
Since I’m waiting for circuit boards for OpenBeacon Mini to arrive, I want to keep the waiting time as productive as possible, so I’ve been working on the firmware. Specifically, one of my recent goals was to factor all of the modulation code out of the spaghetti mess that is the current state of the OpenBeacon 2 firmware (which is my starting point for OpenBeacon Mini).
In that vein, today I managed to finish up work on release v1.0.0 of the Etherkit Morse Arduino library. The majority of the coding work was done during my last few Twitch livestreams, so other than tweaking and cleaning up the code, most of the work today consisted of creating documentation and getting the repository in shape to be a proper Arduino library.
The way that this library functions is quite simple. Since timing in Morse code sending is critical, the end user of the library is required to provide a function that calls the library’s update method every one millisecond. This type of interface was chosen so that the library can be platform agnostic (since Arduinos come with different microcontrollers which have totally different timer functions). An transmit output pin and speed in words per minute is specified when the class in instantiated, and then all you have to do is call the class’s send method to send Morse code on the digital output pin. Alternately, you can have your sketch poll the class’s tx variable and act on it accordingly. Pretty easy stuff.
I’ve put in a request for the library to be included in the official Arduino Library Manager, so if you want to give it a try, wait a day or so for it to be listed there. If you really can’t wait, there are instructions in the README about how to manually install it. Hopefully you find it useful, and as always, please file your bug reports and suggestions for improvements as an issue on GitHub. Thanks!
If you watched my previous Twitch stream, you may have seen that I completed the layout of the first PCB spin of OpenBeacon Mini. Today I ordered the PCBs from DirtyPCBs, along with boards for my low-pass filter module, and more Empyrean boards in anticipation of wider beta testing soon.
I wanted to get these boards to the fab before we started to run into the wall of Chinese New Year (which I seem to do nearly every year). I think I’ve ordered them plenty early, and even paid a bit extra for express shipping, so hopefully they’ll be in-hand around the beginning of February.
In the mean time, I’ll be working on some more coding for the OpenBeacon Mini on my Twitch stream and some other ancillary stuff while I’m waiting for the boards to arrive. Stay tuned for further news on this blog.
I managed to finish the layout of the OpenBeacon Mini prototype PCB in KiCad this evening while livestreaming on Twitch. A 3D rendering from KiCad is above. It looks about how I sketched it out and wasn’t too nasty to route, so I got that going for me. So I’ll get on order off to the PCB fab soon. I’d like to get some PCBs completed before Chinese New Year, so I can’t delay very long.
While I’m waiting for my PCBs to be manufactured, there’s still plenty to do. Twitch streaming is kind of nerve-wracking for me yet kind of fun, so I plan to do more. I have a little more gear on the way that will allow me to also Twitch stream from my workbench, so that you can spy over my shoulder there as well. I even have a USB webcam for my microscope so I’ll be able to connect that to Twitch for your viewing pleasure. Stop by sometime on the livestream and chat me up.
I’m happy to report that I managed to pull off my first Twitch stream today, and even got a handful of viewers. There were some initial problems, as I was trying to stream at 1080p, but my wifi connection from my office just couldn’t give enough bandwidth for that to work. After restarting with the stream set to 720p, people were actually able to see my stream. Today’s work was on OpenBeacon Mini. I assigned footprints to the netlist and made a first pass layout of the PCB. I do intend to stream again soon, perhaps even tomorrow. Hopefully I’ll be able to finish the PCB layout on the next session.
Per my last blog post, I’ve completely deleted my Patreon account. Those days are over and are not coming back. I’m still not sure what will replace it, or if anything will. It is already difficult for me to ask for money in return for mostly intangible benefits. Losing the Patreon monthly income will hurt a bit, as that was the funds I was using to pay for OpenBeacon Mini (and other project) development. I only sell a modest amount of the Si5351A Breakout Boards via Etherkit; basically just enough to pay for keeping the lights on there for now.
So allow me to start using this blog again for what I was doing on Patreon, sans the locked content.
OpenBeacon Mini has a schematic finished and I’m just about ready to lay out the PCB. Empyrean (my Arduino Zero derivative) testing is going to be delayed a bit while I figure out how to fund the beta batch. Those two projects are going to be my main focus and I hope to be going into release with both of them by Q1 2018. Further down the line, I don’t want to speculate too much, but I’ll probably tidy up and finish some half-finished smaller boards that I want to add to my Etherkit lineup in order to fill out the catalog with some more RF products.
I’ll work on ramping up the blogging here, using my own site much as I was using Patreon: to post smaller updates about project progress. I always felt the need to make more substantial posts here, which often deterred me from writing. I believe that was a mistake. Expect to see more content in line with microblogging here in the future. Thanks for hanging in there.
If you’ve been reading my blog for any amount of time, you’ve probably observed that I’m a big fan of all things open source, especially on the hardware side of things. One area where OSHW seems to be lagging a bit is in the test & measurement department, so it was a very pleasant surprise for me to stumble upon a fairly new channel on YouTube about a month ago.
As you can see from the first video, the presenter (sorry, I couldn’t find the name of the bloke who makes these videos) gives an overview of the cheap logic analyzers on the market that can be loaded with open source firmware and then gives a very detailed demonstration on how to use the devices with the nifty open source Sigrok T&M suite (especially the PulseView GUI tool) and how to use a Linux environment and scripting to take measurements.
If you have any interest in this space, this is definitely a channel to which you should subscribe. There is also a show notes site that has links and other resources for the videos.
Using C++ in Arduino
In another case of me stumbling upon something which takes me down a rabbit hole, last week I was watching coding videos on YouTube when this one was recommended in the comments of another:
It’s quite a long video, but if you have any interest in coding and are an old fart who grew up with 8-bit personal computers (or are at least a fan of retrocomputing), then the time will pass quickly on this one. It sounds crazy, but the presenter (Jason Turner) of this talk was able to make a game for the Commodore 64 in modern C++! The way he did it was to create a tool to convert from the 80386 flavor of x86 assembler to 6502 assembler (well really 6510 in this case), which apparently is more feasible than you may think. His development environment is an online tool called Compiler Explorer, which for some reason I only learned about with this video. It automagically spits out assembler from C++ compiled from a variety of different compilers. In this case, the Turner created a custom local version of this tool to do the 6502 conversion.
I was gobsmacked at multiple times in this video. Many of the newest C++ features (from the C++17 standard) were used. With some careful coding, Turner was able to produce code with literally no overhead from all of the C++ features. The compiler was able to optimize many lines of C++ down to a handful of assembler op codes. Just watch it, you’ll be amazed as well.
This video, in conjunction with the series of posts that Hackaday has been running about using C++11 in Arduino, has convinced me that it would worth it to investigate the use of C++ in the Arduino coding environment. Arduino library coders already have to use a base level of C++ when they write for the ecosystem, but most people who write sketches do it in vanilla C-style (well, the bastardized Arduino version of it anyway). After seeing that talk, I had a lot of preconceptions of C++ overhead blown away. The ability to use the modern features of C++11 sound tempting indeed, so I plan to do some investigations into the feasibility of incorporating more C++ patterns into Arduino sketches, and I’ll be posting my findings here. Stay tuned.
KiCad PCB Rendering Tool
I have a habit of skimming my RSS reader (yes, I’m one of those old fogies who still uses one) in the morning while drinking my coffee, opening tabs of interesting things to examine in further detail later, while simply reviewing the rest of the new posts. Sometimes that means it takes me a bit to get back around to something intriguing among my many browser tabs.
Such is the case with this article from Hackaday. It’s just a short blurb about a new open source Python tool for making 2D renderings of KiCad boards. The attached demonstration image certainly looked nice. When I finally got around to downloading the code from GitHub and trying it out on one of my designs, I was pleasantly surprised. The script made a very sharp SVG rendering of my board, but unfortunately, there are only a handful of components in the PcbDraw-Lib library, which meant that most of my stuff didn’t get rendered.
Since I’ve been looking for a way to make nice illustrations of my PCBs for documentation and promotional purposes, I decided that I’d invest some time in adding components to the library, since I think the project has a lot of promise. After about half a day of muddling through making component drawings in Inkscape by studying datasheet engineering drawings, I was able to output a complete render of my Empyrean board, which you can see above. I’m quite happy with the result.
I’ve got a pull request in for the components that I’ve created so far, and as I continue to use the tool and fill out more of the library, I will continue to submit them upstream. While it’s still pretty rough around the edges, this project gets a strong recommend from me.
It has been awfully quiet on the public front here for sure, but I have been working on quite a bit of things behind the scenes here at Etherkit Galactic HQ. It’s been a challenging year since I last wrote about the personal things going on here, but things have been going reasonable well after a rough half-year immediately following that post. I’m just about ready to attempt to revamp Etherkit, however there are still a few challenging roadblocks to overcome, and I could use a bit of guidance.
The most difficult issue is trying to re-bootstrap the business financially. I’m currently only selling the Si5351A Breakout Board, which obviously isn’t enough to expand a business upon. The possibility of a capital infusion unfortunately broke down, and so the only practical way forward at this point is most likely another crowdfunding campaign.
As mentioned in the opening paragraph, I have been working on various projects, and so I do have some candidates. Many of the projects that are in the works or only even in the planning stages require the use of a microcontroller, and so last year I decided to make my own Arduino-compatible microcontroller board family which I can then use as the heart of many of these products. I’ve taken a real liking to the Arduino Zero because of its speed and features, but the cost is fairly high and the standard Arduino form factor isn’t great for many purposes. Therefore, I have decided to make a new standalone board derived from the Zero which I call Empyrean, and you can see in the photo at the top of the post. It comes in two flavors: Alpha and Beta. The Alpha is based on the Atmel ATSAMD21G18A microcontroller, same as the Arduino Zero. The Beta uses a controller (ATSAMD21G16B) with a bit less flash and RAM than the Zero (but still more than an Arduino Uno), but is also priced similarly to the ATmega328 line of microcontrollers. Both come on a small board similar in size to the Nano and has nearly all of the same circuitry of the Arduino Zero except for the EDBG support.
It is true that there are a flood of Arduino clones out there and this makes entering the market with another one somewhat crazy. My value proposition for Empyrean is based on the confluence of breadboard-friendly form factor along with a wallet-friendly price. My target price point is around $15 for Alpha and $10 for Beta. While that is a fair bit more than your typical eBay Nano clone, Empyrean would also be quite a bit more powerful than a Nano, in both clock speed and available memory. So my question to you, dear reader, is whether you would be interested enough in this product to back a crowdfunding campaign in order to have it made? I do plan to make a serious push on a radio soon, but it would be nice to ramp up the business before that, while also solidifying the microcontroller platform that will be used in future products. Let me know what you think in the comments, or send me an email.
In the mean time, I thought I’d let you know that I’m working on a Rev D board spin of the Si5351A Breakout Board. You can see a prototype in beautiful OSHPark purple above. The most significant changes in this revision will be to change the coupling of the reference oscillator to the Si5351 XA input pin to meet datasheet specs and to panelize the board in preparation for future pick-and-place operations (they are currently hand-assembled!).
Perhaps even more interesting is that I also hope to be able to soon offer a frequency calibration report with every board sold. Thanks to LA3PNA, I am now in possession of a decent 10 MHz GPSDO to use as a lab reference, which will allow me to measure the frequency correction value accurately enough for hobbyist usage. I now have a small printer on hand, and so now what I need to do is add new code to my board test script to measure the correction value and print it for inclusion with each board sold. Stay tuned for notification when I’m ready to go live with this; hopefully soon.
Let me reiterate: I’d love to hear your thoughts about the above proposals. I’m interested in serving the needs of my customers. Thank you!
I know that the updates here have been extremely sparse. For that I do apologize. Things are slowly starting to settle into a new normal around here, and I’ve been able to regain the ability to put time back into work. There’s a large to do list on my whiteboard, and many of the things on that list depend on improvements and bug fixes to the Si5351 Arduino library. So that has been my first priority as I dip my toes back in the water.
There were quite a few features of the Si5351 that the older versions of the library did not support, such as all of the 8 outputs of the variants excluding the A3 and the VCXO of the B variant. Also, there is a pretty big bug in how the tuning algorithm handles multiple outputs assigned to the same PLL, which causes tuning errors to crop up.
Therefore, I decided in one fell swoop that I needed to totally rewrite the tuning algorithm and add support for as many of the neglected features as I could before moving on to other projects involving the Si5351. Over the last month, I’ve been hacking away on the code in my spare time, and I’m glad to finally be able to announce that a beta version of the Si5351 Arduino v2.0.0 library is ready for public use.
Because it’s such a drastic change to the underlying code, I’d like to have it in limited beta release before doing a final release via the Arduino Library Manager. So that means that if you would like to try it (and I encourage you to do so), then you’ll need to install it manually, which isn’t terribly difficult.
Go here and click on the green button on the upper right that says “Clone or download”. Select “Download ZIP”. Next, find where on your filesystem your Arduino libraries folder resides and delete the existing “Etherkit Si5351” folder. Inside the ZIP file you just downloaded, there is a folder entitled “Si5351Arduino-libupdate”. Unzip this folder into the Arduino libraries folder, and then restart the Arduino IDE.
Since this is a new major version release, I took the opportunity to tweak the interface a bit, which means that you’ll have to adjust your current code to work with the new library (but fortunately not too much). You’ll find the details on how to do that here.
Please check out the updated documentation on the GitHub page, as it has been greatly expanded and should explain all of the new features in detail. Also, quite a few new example sketches have been added to the library, which you can find in the usual place in the Arduino IDE. I encourage you to try the new library in your existing projects, as it should be a bit more streamlined and stable. Also, there is plenty of opportunity to make new projects with the B and C variant ICs. If you do encounter any problems with the new library version, I would like to strongly encourage you to use the Issues feature of GitHub to let me know so that I can get on to fixing it as soon as possible. When I’m satisfied that there are no big show-stopper bugs in the code, I’ll merge it to the master branch of the repository and tag it for release via the Arduino Library Manager, but I need help in testing it before I can do that.
Once there’s a stable release of this version of the library out in the wild, then I’ll be able to move forward with other projects based on this Si5351. With any luck, some more interesting things will be coming from this shack again in the near future. Thank you for all of your help and support!
Edit: an exclusive look into the development process: