Hackaday editors Mike Szczys and Elliot Williams navigate the crowded streets of the hackersphere for the most interesting hardware projects seen in the past week. Forget flip-dot displays, you need to build yourself a sequin display that uses a robot finger and sequin-covered fabric to send a message. You can do a lot (and learn a lot) with a 1-bit computer called the WDR-1. It’s never been easier to turn a USB port into an embedded systems dev kit by using these FTDI and Bluepill tricks. And there’s a Soyuz hardware teardown you don’t want to miss.
Take a look at the links below if you want to follow along, and as always tell us what you think about this episode in the comments!
We’d wager most hackers are familiar with FTDI as the manufacturer of the gold standard USB-UART interfaces. Before parts like the ultra cheap CH340 and CP2102 became common, if you needed to turn a USB cable into a TTL UART device, “an FTDI” (probably an FT232RL) was the way to make that happen. But some of the parts in the FT232* family are capable of much more. Wanting to get at more than a UART, [linker3000] designed the Shukran to unlock the full potential of the FT232H.
The FT232H is interesting because it’s an exceptionally general purpose interface device. Depending on configuration it can turn USB into UART, JTAG, SPI, I2C, and GPIO. Want to prototype the driver for a new sensor? Why bother flashing your Teensy when you can drive it directly from the development machine with an FT232H and the appropriate libraries?
The Shukran is actually a breakout for the “CJMCU FT232H” module available from many fine internet retailers. This board is a breakout that exposes a USB-A connecter on one side and standard 0.1″ headers on the other, with a QFN FT232H and all the passives in the middle. But bare 0.1″ headers (in a square!) require either further breadboarding or a nest of jumper wires to be useful. Enter the Shukran. In this arrangement, the CJMCU board is cheap and handles the SMT components, and the Shukran is easy to assemble and makes it simple to use.
The Shukran gives you LEDs, buttons and switches, and a bunch of pull up resistors (for instance, for I2C) on nicely grouped and labeled headers. But most importantly it provides a fused power supply. Ever killed the USB controller in your computer because you forgot to inline a sacrificial USB hub? This fuse should take care of that risk. If you’re interested in building one of these handy tools, sources and detailed BOM as well as usage instructions are available in the GitHub repo linked at the top.
Don’t you just hate it when dev boards have some annoying little quirk that makes them harder to use than they should be? Take the ESP32-CAM, a board that started appearing on the market in early 2019. On paper, the thing is amazing: an ESP32 with support for a camera and an SD card, all for less than $10. The trouble is that programming it can be a bit of a pain, requiring extra equipment and a spare finger.
Not being one to take such challenges lying down, [Bitluni] has come up with a nice programming board for the ESP32-CAM that you might want to check out. The problem stems from the lack of a USB port on the ESP32-CAM. That design decision leaves users in need of a USB-to-serial adapter that has to be wired to the GPIO pins of the camera board so that programs can be uploaded from the Arduino IDE when the reset button is pressed. None of that is terribly complex, but it is inconvenient. His solution is called cam-prog, and it takes care of not only the USB conversion but also resetting the board. It does that by simply power cycling the camera, allowing sketches to be uploaded via USB. It looks to be a pretty handy board, which will be available on his Tindie store.
To demonstrate the add-on, he programmed his ESP32-CAM and connected it to his enormous ping pong ball video wall. The video quality is about what you’d expect from a 1,200 pixel display at 40 mm per pixel, but it’s still pretty smooth – smooth enough to make his interpretive dance moves in the last few minutes of the video pretty interesting.
ESP8266 development boards like the Wemos D1 Mini and NodeMCU are an excellent way to get a one-off project up and rolling quickly, but their size and relative complexity mean they aren’t necessarily a good choice for even short-run production hardware. On the other hand, programming the bare ESP modules can be something of a pain. But thanks to [Greg Frost], flashing those tiny little boards just got a lot easier.
His 3D printed design uses pogo pins to securely connect to the board’s castellated edges, which also holds it in place during the programming process. On the back side there’s just a few jumper wires and a couple of resistors, which ultimately lead to the FT232R FTDI board that actually connects the chip to the computer so you can program it.
We’d like to see a back panel that encloses the wiring, and perhaps an alternate version that deletes the space for the FTDI board in favor of a row of header pins. Both easy enough modifications to the basic design should [Greg] or anyone else feel so inclined. But even as it is, this is a great little programmer that can be sourced and assembled easily and cheaply.
FTDI’s chips have varying capabilities, but most can do more than just acting as a USB-connected COM port. It’s possible to use the chips for SPI, I2C, or even bitbanging operation. [jayben] has done the hard work of identifying the best drivers to use depending on your operating system, and then gone a step further to demonstrate example code for sending data over these various interfaces. The article not only covers code, but also shows oscilloscope traces of output, giving readers a strong understanding of what should be happening if everything’s operating as it should. The series rounds out with a primer on how to use FTDI hardware to speak the SWD protocol to ARM devices for advanced debugging use.
It’s a great primer on how to work effectively with these useful chips, and we imagine there will be plenty of hackers out there that will find great use to this information. Of course, it’s important to always be careful when sourcing your hardware as FTDI drivers don’t take kindly to fake chips.
When a project has outgrown using a small microcontroller, almost everyone reaches for a single-board computer — with the Raspberry Pi being the poster child. But doing so leaves you stuck with essentially a headless Linux server: a brain in a jar when what you want is a Swiss Army knife.
It would be a lot more fun if it had a screen attached, and of course the market is filled with options on that front. Then there’s the issue of designing a human interface: touch screens are all the rage these days, so why not buy a screen with a touch interface too? Audio in and out would be great, as would other random peripherals like accelerometers, WiFi, and maybe even a cellular radio when out of WiFi range. Maybe Bluetooth? Oh heck, let’s throw in a video camera and high-powered LED just for fun. Sounds like a Raspberry Pi killer!
And this development platform should be cheap, or better yet, free. Free like any one of the old cell phones that sit piled up in my “hack me” box in the closet, instead of getting put to work in projects. While I cobble together projects out of Pi Zeros and lame TFT LCD screens, the advanced functionality of these phones sits gathering dust. And I’m not alone.
Why is this? Why don’t we see a lot more projects based around the use of old cellphones? They’re abundant, cheap, feature-rich, and powerful. For me, there’s two giant hurdles to overcome: the hardware and the software. I’m going to run down what I see as the problems with using cell phones as hacker tools, but I’d love to be proven wrong. Hence the “Ask Hackaday”: why don’t we see more projects that re-use smartphones?
When working on a project that needs to send data from place to place the distances involved often dictate the method of sending. Are the two chunks of the system on one PCB? A “vanilla” communication protocol like i2c or SPI is probably fine unless there are more exotic requirements. Are the two components mechanically separated? Do they move around? Do they need to be far apart? Reconfigurable? A trendy answer might be to add Bluetooth Low Energy or WiFi to everything but that obviously comes with a set of costs and drawbacks. What about just using really long wires? [Pat] needed to connect six boards to a central node over distances of several feet and learned a few tricks in the process.
When connecting two nodes together via wires it seems like choosing a protocol and plugging everything in is all that’s required, right? [Pat]’s first set of learnings is about the problems that happen when you try that. It turns out that “long wire” is another way to spell “antenna”, and if you happen to be unlucky enough to catch a passing wave that particular property can fry pins on your micro.
Plus it turns out wires have resistance proportional to their length (who would have though!) so those sharp square clock signals turn into gently rolling hills. Even getting to the point where those rolling hills travel between the two devices requires driving drive the lines harder than the average micro can manage. The solution? A differential pair. Check out the post to learn about one way to do that.
It looks like [Pat] needed to add USB to this witches brew and ended up choosing a pretty strange part from FTDI, the Vinculum II. The VNC2 seemed like a great choice with a rich set of peripherals and two configurable USB Host/Peripheral controllers but it turned out to be a nightmare for development. [Pat]’s writeup of the related troubles is a fun and familiar read. The workaround for an incredible set of undocumented bad behaviors in the SPI peripheral was to add a thick layer of reliability related messaging on top of the physical communication layer. Check out the state machine for a taste, and the original post for a detailed description.