Versatile Reflow Oven Controller Uses ESP32-S2

April 14, 2022 by Al Williams 12 Comments

[Maker.Moekoe] wanted a single controller board that was usable with different reflow ovens or hotplates. The result is a versatile board based on the ESP32-S2. You can see a video of the board’s assembly in the video below.

The board sports several inputs and outputs including:

2x MAX6675 thermocouple sensor input
2x Fan output with flyback diodes
2x Solid state relay output
3x Buttons
1x LED
1x Buzzer
1x Servo motor output
0.96 inch OLED display

You could probably find a use for the board for other similar applications, not just ovens.

The video is oddly relaxing, watching parts reflow. It is like watching a 3D printer, no matter how many times we see it, we still find it soothing to watch. You can also see how he integrated the board with a toaster oven.

Overall, the board looks great and the workmanship is also very good. If you’ve never seen anyone set heat-set threaded inserts into a 3D printed piece, be sure to watch around the four minute mark.

We’ve seen plenty of oven projects. You can even use an Easy Bake oven.

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Arming With An OS

April 13, 2022 by Al Williams 28 Comments

We see tons of projects with the infamous “Blue Pill” STM32 boards. They are cheap and plentiful and have a lot of great features, or at least they were before the chip shortage. I recently picked up a “Black Pill”, which is very similar but has an even more powerful processor. For a few bucks, you get an ARM CPU that can run at 100 MHz (but with USB, probably 96 MHz). There’s 512 kB of flash and 128 kB of RAM. There’s a USB type C port, and even a button and an LED onboard. The thing fits on a breadboard and you can program it with a cheap STLink dongle which costs about $10.

Of course, you then have to consider the software. The STM32Cube stuff is a lot to set up and learn but it does let you do just about anything you can imagine. Then there is the STM32Duino plug-in that lets you use it as a beefy Arduino. That works and is easy enough to set up. However, there’s also Mbed. The only problem is that Mbed doesn’t work right out of the box. Turns out, though, it isn’t that hard to set up. I’ll show you how easy it is to get things going and, next time, I’ll show you a practical example of a USB peripheral that uses the mBed RTOS features.

First Steps

Obviously, you are going to need a Black Pill. There are at least two choices but for as cheap as they are there is little reason not to get the STM32F411 version that has more memory. The DIP form factor will fit in whatever breadboard you happen to have and a USB C cable will power the board so unless you are driving a lot of external circuitry, you probably don’t need an external supply.

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Mindblowing Graphics From An ATtiny85

April 12, 2022 by Elliot Williams 24 Comments

[Görg Pflug] wrote in with his really nice graphics library. It’s got multiple layers, two text consoles, greyscale, internal halftoning, and sprites. It can pull off a number of classic graphics tricks and demos. Oh yeah, and did we mention it runs on a freaking ATtiny85 and an I2C OLED screen?!

This is an amazing piece of work — if you’d asked us if this was possible, we would have probably said “no”. And now it’s yours to use in your own projects. The GitHub repo is full of demos showing off everything from switching between multiple layers, extremely rapid text scrolls, animations, boing balls, and even a Wolfenstein-style raycaster. On an ATtiny85.

There’s a demo video, embedded below, that shows it all off, but honestly you have to think about what’s going to to be suitably wowed. The first demo just seems to have a graphic wave over static text, for instance. No big deal? It’s blending the greyscale layers together and dithering them out to black and white for the OLED in real time! On an ATtiny85.

While the library is written in straight C++, there are even a couple examples of how you’d integrate this with Arduino’s Wire library if you so wished. We don’t know about you, but this makes us want to whip together an ATtiny85 and SSD1306 OLED demo board just to start playing around. This isn’t just an amazing hack, but it would also be a useful way to add graphics and a nice console to any project you’re working on.

Did we mention it’s all done on an ATtiny85? Over I2C? Kudos!

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ESP32: Is Two Better Than One?

April 4, 2022 by Al Williams 9 Comments

We’ve looked at the WROOM-DA module before. It’s an ESP32 with two antennas, and [Andreas Spiess] says it is the ugliest ESP32 he’s ever seen. But beauty is only skin deep, after all. Did [Andreas] find beauty in the twin antennas? Watch the video below and see for yourself.

According to the block diagram, the twin antennas are not used simultaneously but offer diversity one at a time. There is also ~~8GB~~ 8 MB of flash, double the amount on traditional WROOM modules. Mounting the device was a bit difficult since most ESP32 carrier boards will block some portion of the antenna array.

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SAMD11 Provides Two Serial Ports For Price Of One

April 4, 2022 by Tom Nardi 22 Comments

While the average computer user likely hasn’t given much thought to the lowly serial port in decades, the same can’t be said for the hardware hacker. Cheap serial-to-USB adapters are invaluable for snooping debug ports or programming chips, and if you ask us, you can never have too many laying around the bench. [Quentin Bolsée] loves them so much that he’s even figured out how to build a dual-port adapter with a SAMD11C14 microcontroller.

As [Quentin] explains in the write-up, this isn’t just some kind of Y-cable. When connected to the host computer, the adapter shows up as two distinct serial ports, each with independent settings for things like baud rate and parity. This handy little gadget will let you tap into the serial ports of two devices simultaneously if you’re looking to do some Hollywood-style hacking, but more practically, it allows you to establish a debug and programming interface to the same board using just one USB connection.

[Quentin] milled a custom PCB for his adapter, which we have to say looks phenomenal, but those with more limited equipment at home should be able to send the MIT licensed board files off for production. He’s also provided the source code for the SAMD11C14’s firmware, so you’ve got everything you need to spin up your own version of this neat tool.

Two ports not enough for your parallel hacking needs? Believe it or not, we’ve also seen a quad USB-to-serial adapter that you can put together, though it’s a considerably more complex circuit.

Turn Timing Diagrams Into ASCII Art, For Friendlier Pasting

April 4, 2022 by Donald Papp 21 Comments

We all use text-based fields at one time or another, and being limited to ASCII only can end up being a limitation. That’s what led [Luke Wren] to create asciiwave, a fantastic tool that turns WaveDrom timing diagrams into ASCII art. Unlike images, ASCII timing diagrams are suitable for pasting into comment fields, change logs, or anywhere else that accepts text only. [Update: As the author kindly shared in the comments below, this tool’s original niche is pasting into HDL (e.g. Verilog) source code comments, where it has a special kind of usefulness.]

WaveDrom itself is a nifty JavaScript tool that we have covered before. It accepts timing diagrams expressed as JSON data, and renders nicely-readable digital timing diagrams as images directly inside one’s browser.

As cool and useful as that is, images can’t be pasted into text fields. That’s where asciiwave comes in. It reads the exact same format that WaveDrom uses, but generates an ASCII-art timing diagram instead. So if you’ve found WaveDrom useful, but wish you could generate ASCII versions, here’s your solution.

Flashing TI Chips With An ESP

April 3, 2022 by Bryan Cockfield 29 Comments

Texas Instruments is best known to the general public for building obsolete calculators and selling them at extraordinary prices to students, but they also build some interesting (and reasonably-priced) microcontrollers as well. While not as ubiquitous as Atmel and the Arduino platform, they can still be found in plenty of consumer electronics and reprogrammed, and [Aaron] aka [atc1441] demonstrates how to modify them with an ESP32 as an intermediary.

Specifically, the TI chips in this build revolve around the 8051-core microcontrollers, which [Aaron] has found in small e-paper price tags and other RF hardware. He’s using an ESP32 to reprogram the TI chips, and leveraging a web server on the ESP in order to be able to re-flash them over WiFi. Some of the e-paper displays have built-in header pins which makes connecting them to the ESP fairly easy, and once that’s out of the way [Aaron] also provides an entire software library for interacting with these microcontrollers through the browser interface.

Right now the project supports the CC2430, CC2510 and CC1110 variants, but [Aaron] plans to add support for more in the future. It’s a fairly comprehensive build, and much better than buying the proprietary TI programmer, so if you have some of these e-paper displays laying around the barrier to entry has been dramatically lowered. If you don’t have this specific type of display laying around, we’ve seen similar teardowns and repurposing of other e-paper devices in the past as well.

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