Button, Button, Who’s Got The (Pico) Button?

September 20, 2023 by Al Williams 26 Comments

There is an episode of Ren and Stimpy with a big red “history eraser’ button that must not be pressed. Of course, who can resist the temptation of pressing the unpressable button? The same goes for development boards. If there is a button on there, you want to read it in your code, right? The Raspberry Pi Pico is a bit strange in that regard. The standard one lacks a reset button, but there is a big tantalizing button to reset in bootloader mode. You only use it when you power up, so why not read it in your code? Why not, indeed?

Turns out, that button isn’t what you think it is. It isn’t connected to a normal CPU pin at all. Instead, it connects to the flash memory chip. So does that mean you can’t read it at all? Not exactly. There’s good news, and then there’s bad news.

The Good News

The official Raspberry Pi examples show how to read the button (you have read all the examples, right?). You can convert the flash’s chip-select into an input temporarily and try to figure out if the pin is low, meaning that the button is pushed. Sounds easy, right?

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Open Source Tracker Keeps An Eye On Furry Friends

September 19, 2023 by Richard Baguley 49 Comments

Most of the time, you’ll know where your cats are — asleep on the bed about 23.5 hours a day and eating or pooping the rest of the time. But some cats are more active than others, so there’s commercial options for those who want to keep tabs on their pet. Unfortunately, [Sahas Chitlange] didn’t like any of them, so he designed and built his own open source version: FindMyCat.io.

The system is in two parts: a module that fits onto a cat collar, and a home station that, well, stays at home. It offers a variety of tracking modes. In home mode, the home station signals the collar every 10 seconds, which stays in a deep sleep most of the time. If the collar doesn’t get a signal from the home station, it switches to ping mode, where it will wait for a signal from the FindMyCat over the LTE-M connection and report its location.

Finally, the app can set the collar to Lost Kitteh mode, where the collar will send a location to the app every seven minutes or thirty seconds. The collar also supports a direction-finding feature, using the ultra wideband (UWB) feature of recent Apple iPhones to point you in the direction and distance of the tracked cat.

The collar is built around a Nordic Semiconductor NRF-9160, a System in a Package (SiP) that does most of the heavy lifting as it includes GPS, an LTE-M modem, and an ARM processor. One interesting feature here: [Sahas] doesn’t make his antennas on the PCB, but instead uses an Ignion NN03-310, an off-the-shelf antenna that is already qualified for LTE-M use. That means this system can be connected to almost any LTE-M network without getting yelled at for using unqualified hardware and making the local cell towers explode.

The collar also includes a DWM3001CDK ultrawideband (UWB) module used for the locator feature. The accompanying app uses this and Apple’s UWB support to show the user which direction the cat is in, and how far away it is. The app isn’t in the Apple App Store yet, so you’ll need to sign up for an Apple Developer account to use it. We’d love to hear from anyone who takes it for a test drive with their own pet.

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ESP32 Drives Tiny FM Radio

September 14, 2023 by Bryan Cockfield 21 Comments

Even as music streaming services and podcast apps dominate most of our listening time, it’s still a great idea to keep a radio on hand, if for nothing else than in emergency situations. After all, blizzards, hurricanes, and other natural disasters can quickly take out both home and mobile Internet access. If you’d like to have an FM radio with the absolute smallest footprint, take a look at this one built around an ESP32.

While the radio uses the ESP32 as the main control board hosted by a TTGO T-Display board which adds a 1.14 inch ST7789V IPS panel, it also makes use of the TEA5767 chip for handling the FM radio signals. As [Volos Projects] has it programmed, the ESP32 stores five preset channels which can be toggled using two buttons at the bottom of the device. There’s also some circuitry to handle output to headphones or a stereo.

For making the radio even smaller, some of the audio processing could be done on the ESP32 instead, although its much simpler to take a slightly larger footprint and offload this to an audio processing chip. Since the source code for this project is open, modifications could be done including adding seek/tune functionality instead of relying only on presets. If you’re not building this for emergencies, though, and your entire area is dominated by cookie cutter corporate-owned radio stations, an ESP32 with an internet connection is great for accessing better radio stations around the world.

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This Keyboard Doesn’t Work Without Game Boy Cartridges

September 11, 2023 by Kristina Panos 9 Comments

Just when we though we’d seen it all when it comes to custom keyboards (or most of it, anyway), along comes [Stu] with the TypeBoy and TypePak. Like the title implies, TypeBoy and TypePak are inseparable.

Let’s talk about TypePak first. Somehow, some way, [Stu] managed to fit the following into an aftermarket Game Boy Advance cartridge: a XIAO BLE microcontroller, a Sharp Memory Display, a shift register, and a LiPo battery. It’s all there in [Stu]’s incredibly detailed blog post linked above.

Amazing, no? And although [Stu] claims that the TypePak is mostly for aesthetics (boy howdy), it will make swapping microcontrollers much easier in the future.

If this looks sort of familiar, you may remember a likely render of [mujimaniac]’s board called the GIGA40 that also employed a cartridge system. Allegedly there is now a working prototype of the GIGA40.

Would you like to give the TypeBoy and TypePak a go? Files are available on GitHub, but this doesn’t seem like a project for the faint of heart.

Speaking of stuffing things in to Game Boy cartridges, check out this SNES cartridge turned hard drive enclosure.

Via KBD

This Arduino Debugger Uses The CH552

September 11, 2023 by Al Williams 16 Comments

One of the things missing from the “classic” Arduino experience is debugging. That’s a shame, too, because the chips used have that capability. However, the latest IDE has the ability to work with external debuggers and if you want to get started with a classic ATMega Arduino, [deqing] shows you how to get started with a cheap CH552 8-bit USB microcontroller board as the debugging dongle.

The CH552 board in question is a good choice, primarily because it is dirt cheap. There are design files on GitHub (and the firmware), but you could probably pull the same trick with any of the available CH552 breakout boards.

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Cheap LCD Uses USB Serial

September 11, 2023 by Al Williams 19 Comments

Browsing the Asian marketplaces online is always an experience. Sometimes, you see things at ridiculously low prices. Other times, you see things and wonder who is buying them and why — a shrimp pillow? But sometimes, you see something that probably could have a more useful purpose than the proposed use case.

That’s the case with the glut of “smart displays” you can find at very low prices. Ostensibly, these are being sold as system monitors. A business-card-sized LCD hooks up via USB and shows your CPU speed, temperature, and so on. Of course, this requires sketchy Windows software. I don’t run Windows, and if I did, I wouldn’t be keen to put some strange service on just so I could see tiny displays of my system information. But a 3.5-inch IPS LCD screen for $15 or less probably has some other uses. But how to drive it? Turns out, it is easier than you think and the hardware looks reasonably hackable, too.

Like a lot of this cheap stuff, these screens are sold under a variety of names, and apparently, there are some subtle differences. Two of the main makers of these screens are Turing and XuanFang, although you rarely see those names in the online listings. As you might expect, though, someone has reverse-engineered the protocol, and there is Python software that will replace the stock Windows software the devices use. Even better, there is an example of using the library for your own purposes.

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Open Deck Is Your Window To Shortcuts

September 10, 2023 by Kristina Panos 11 Comments

Once in a while, we see projects that could easily pass for commercial products. This is one of those projects: a (surprisingly) low-cost DIY macro pad from [Josh R] that was designed to be a cheaper alternative to the various stream decks out there. Between the carbon fiber top plate and the crystal-clear acrylic keycaps, this is quite the elegant solution.

This lovely little macro pad is built around the ESP8266, specifically the WEMOS D1 Mini V4. However, the most vital part to get right is the screen, which must be a 128 x 160 TFT display in order to line up with the 3D printed frame that divides it into fourths. Custom parts like the acrylic keycaps and the carbon fiber top plate are available on Tindie if you don’t have access to a CNC.

Operationally, Open Deck has a nice-looking GUI. Once programmed, each shortcut is capable of having three beneath it, with the fourth button reserved for Home. Be sure to check out the extremely satisfying build video after the break.

Want a stream deck, but don’t want to build it? Just dig up an old phone or tablet.

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