Lmst

#LifeHack: If you need to open or close a coin cell compartment meant to be opened with a coin but don't have one handy or don't want too touch one, just use an USB-C plug. Fits well.

#USBC #CoinCell #CoinDriver #Coin

An USB-C plug shown as it fits well into the shallow slot of the lid for a coin cell compartment on the back of a bicycle light remote control.

New video! Replacing the rechargeable lithium cell on my Blizzard 1230 MK IV Amiga 1200 accelerator card.

YouTube: https://youtu.be/-sdXLAXbpfQ
PeerTube: https://makertube.net/w/qLLGtqax621LFSzxFgZj1Q

#Amiga #A1200 #Amiga1200 #Commodore #Blizzard1230 #Phase5 #Battery #CoinCell #RealTimeClock #Accelerator #RetroComputing #VintageComputing

Thumbnail for my video, showing my hands holding my Blizzard 1230 Amiga accelerator card. The overlayed text reads "Blizzard 1230 MK IV Battery Replacement".

What the hell is the point with the #coincell CR2032 in the #SunBlade100 ? #sunmicrosystems

Duracell now has (I assume) the same chemical Nintendo uses on Switch cartridges on their coin-cell batteries. Surprised they didn't do it sooner, but you know it costs more money.

#Duracell #Nintendo #Switch #NintendoSwitch #CoinCell #battery

LED Ring Brings the Bling https://hackaday.com/2023/11/28/led-ring-brings-the-bling/ #WearableHacks #LEDHacks #coincell #SMDLED #leds #ring

2023 Halloween Hackfest: Flickering Pumpkin Pin Is Solidly Built https://hackaday.com/2023/10/04/2023-halloween-hackfest-flickering-pumpkin-pin-is-solidly-built/ #2023HalloweenHackFest #flickeringleds #WearableHacks #flickeringled #HolidayHacks #jackolantern #pumpkinpin #contests #coincell #pumpkin #leds

Minimizing Stress on a Coin Cell Battery https://hackaday.com/2023/08/10/minimizing-stress-on-a-coin-cell-battery/ #boostconverter #buckconverter #BatteryHacks #switchmode #voltagesag #coincell #battery #dc-dc #life #smps

So, let's inaugurate the transfer from @hkz@mastodon.technology with a photo of the dusty #mainboard of the FLYER #ibmcompatible portable where I desoldered the dead CR2430 #coincell and put an holder for a CR2032.

Just because I wanted some #retrocomputing in my new timeline!

Careful Cuts Lets Logger Last a Year On A Coin Cell

Coin cells are great for backup power for things like real-time clocks, or even for powering incredibly small mechanical devices like watches. But for something like a data logger, running on a standard microcontroller, most people would reach for a lithium cell of some sort. Not so with this build, though, which squeezes every joule of energy from a coin cell in order to run a data logger for a full year.

Won't be needing that anymore.

Most of the design and engineering required to improve the efficiency of the data logger involve standard practices for low-power devices such as shutting off unnecessary components and putting the device to sleep when not actively running, but this build goes far beyond that. The Vcc pin on the RTC was clipped which disables some of its internal logic but still keeps its basic functionality intact.

All of the voltage regulators were removed or disabled in favor of custom circuitry that doesn't waste as much energy. The status and power LEDs were removed where possible, and the entire data logger is equipped with custom energy-efficient code as well.

If you're starting a low-power project, even one that isn't a datalogger, it's worth checking out this build to see just how far you can go if you're willing to hack at a PCB with cutting tools and a soldering iron. As to why this data logger needed such a low power requirement, it turns out it's part of a kit being used in classrooms and using a coin cell brought the price of the entire unit down tremendously. Even if you have lithium cells on hand, though, it's still worthwhile to check out the low power modes of your microcontroller.

Thanks to [Adrian] for the tip!

#microcontrollers #battery #clock #coincell #datalogger #ds3231 #efficiency #energy #microcontroller #power #rtc

Tiny Talisman Warns Wearer About UV Exposure

Given how important our Sun is, our ancestors can be forgiven for seeing it as a god. And even now that we know what it actually is and how it works, it's not much of a reach to think that the Sun pours forth evil spirits that can visit disease and death on those who bask too long in its rays. So an amulet of protection against the evil UV rays is a totally reasonable project, right?

As is often the case with [mitxela]'s projects, especially the more bedazzled ones, this one is approximately equal parts electronics and fine metalworking. The bulk of the video below focuses on the metalwork, which is pretty fascinating stuff. The case for the amulet was made from brass and sized to fit a CR2032 coin cell. The back of the amulet is threaded to act as a battery cover, and some fancy lathe work was needed there. The case was also electroplated in gold to prevent tarnishing, and lends a nice look when paired up with the black solder mask of the PCB.

On the electronics side, [mitxela] took pains to keep battery drain as low as possible and to make the best use of the available space, choosing an ATtiny84 to support a TTP223 capacitive sensing chip and a VEML6075 UV sensor. The touch sensor allows the wearer to wake the amulet and cycles through UV modes, which [mitxela] learned were not exactly what the sensor datasheet said they were. This required a few software hacks, but in the end, the amulet does a decent job of reporting the UV index and looks fantastic while doing it.

#art #attinyhacks #wearablehacks #attiny84 #coincell #jewelry #metalworking #ttp223 #uv #uvindex #uva #uvc #veml6075

One Man’s Quest to Build a Baby Book With Brains

Regular readers will know that Hackaday generally steers clear of active crowdfunding campaigns. But occasionally we do run across a project that's unique enough that we feel compelled to dust off our stamp of approval. Especially if the campaign has already blasted past its funding goal, and we don't have to feel bad about getting you fine folks excited over vaporware.

It's with these caveats in mind that we present to you Computer Engineering for Babies, by [Chase Roberts]. The product of five years of research and development, this board book utilizes an internal microcontroller to help illustrate the functions of boolean logic operations like AND, OR, and XOR in an engaging way. Intended for toddlers but suitable for curious minds of all ages, the book has already surpassed 500% of its funding goal on Kickstarter at the time of this writing with no signs of slowing down.

The electronics as seen from the rear of the book.

Technical details are light on the Kickstarter page to keep things simple, but [Chase] was happy to talk specifics when we reached out to him. He explained that the original plan was to use discreet components, with early prototypes simply routing the button through the gates specified on the given page. This worked, but wasn't quite as robust a solution as he'd like. So eventually the decision was made to move the book over to the low-power ATmega328PB microcontroller and leverage the MiniCore project so the books could be programmed with the Arduino IDE.

Obviously battery life was a major concern with the project, as a book that would go dead after sitting on the shelf for a couple weeks simply wouldn't do. To that end, [Chase] says his code makes extensive use of the Arduino LowPower library. Essentially the firmware wakes up the ATmega every 15 ms to see if a button has been pressed or the page turned, and updates the LED state accordingly. If no changes have been observed after roughly two minutes, the chip will go into a deep sleep and won't wake up again until an interrupt has been fired by the yellow button being pressed. He says there are some edge cases where this setup might misbehave, but in general, the book should be able to run for about a year on a coin cell.

[Chase] tells us the biggest problem was finding a reliable way to determine which page the book was currently turned to. In fact, he expects to keep tinkering with this aspect of the design until the books actually ship. The current solution uses five phototransistors attached to the the MCU's ADC pins, which receive progressively more light as fewer pages are laying on top of them. The first sensor is exposed when the second page of the book is opened, so for example, if three of the sensors are seeing elevated light levels the code would assume the user is on page four.

Opening to the last page exposes all five light sensors.

The books and PCBs are being manufactured separately, since as you might expect, finding a single company that had experience with both proved difficult. [Chase] plans on doing the final assembly and programming of each copy in-house with the help of family members; given how many have already been sold this early in the campaign, we hope he's got a lot of cousins.

So what do you do with an Arduino-compatible book when Junior gets tired of it? That's what we're particularly interested in finding out. [Chase] says he's open to releasing the firmware as an open source project after the dust settles from the Kickstarter campaign, which would give owners a base to build from should they want to roll their own custom firmware. Obviously the peripheral hardware of the book is fairly limited, but nothing is stopping you from hanging some sensors on the I2C bus or hijacking the unused GPIO pins.

If you end up teaching your copy of Computer Engineering for Babies some new tricks, we've love to hear about it.

#arduinohacks #crowdfunding #microcontrollers #toyhacks #atmega328pb #book #coincell #phototransistor

An OLED Photo Frame Powered by the ATtiny85

Rolling your own digital picture frame that loads images from an SD card and displays them on an LCD with a modern microcontroller like the ESP32 is an afternoon project, even less if you pull in somebody else's code. But what if you don't have the latest and greatest hardware to work with?

Whether you look at it as a practical application or an interesting experiment in wringing more performance out of low-end hardware, [Assad Ebrahim]'s demonstration of displaying digital photographs on an OLED using the ATtiny85 is well worth a look. The whole thing can put put together on a scrap of perfboard with a handful of common components, and can cycle through the five images stored on the chip's flash memory for up to 20 hours on a CR2032 coin cell.

As you might expect, the biggest challenge in this project is getting all the code and data to fit onto the ATtiny85. To that end [Assad] wrote his own minimal driver for the SSD1306 OLED display, as the traditional Adafruit code took up too much space. The driver is a pretty bare bones implementation, but it's enough to initialize the screen and get it ready for incoming data. His code also handles emulating I2C over Atmel’s Universal Serial Interface (USI) at an acceptable clip, so long as you bump the chip up to 8 MHz.

For the images, [Assad] details the workflow he uses to take the high-resolution color files and turn them into an array of bytes for the display. Part of that it just scaling down and converting to 1-bit color, but there's also a bit of custom Forth code in the mix that converts the resulting data into the format his code expects.

This isn't the first time we've seen somebody use one of these common OLED displays in conjunction with the ATtiny85, and it's interesting to see how their techniques compare. It's not a combination we'd necessarily chose willingly, but sometimes you've got to work with whats available.

#attinyhacks #softwarehacks #attiny85 #coincell #i2c #oled #ssd1306 #universalserialinterface