Swap The Clock Chip On The Mac SE/30 With An ATTiny85

January 13, 2023 by Tom Nardi 20 Comments

As [Phil Greenland] explains in the first part of his excellent write-up, the lithium battery used to keep the real-time clock (RTC) going on the Macintosh SE/30 has a nasty habit of exploding and leaking its corrosive innards all over the board. Looking to both repair the damage on a system that’s already had a battery popped and avoid the issue altogether on pristine boards, he started researching how he could replace the battery with something a bit more modern.

It turns out, the ATtiny85 is pin-compatible with the Mac’s original RTC chip, and indeed, [Andrew Makousky] had already written some code that would allow the microcontroller to emulate it. This is actually a bit more complex than you might realize, as the original RTC chip was doing double-duty: it also held 256 bytes of parameter random access memory (PRAM), which is where the machine stored assorted bits of info like which drive to boot from and the mouse cursor speed.

But after getting the mod installed, the computer refused to start. It turns out the project targeted earlier machines like the Macintosh Plus and SE, and not his higher-performance SE/30. Thanks to community resources like this KiCad recreation of the SE/30’s motherboard, contemporary technical documents, and his trusty logic analyzer, [Phil] was able to figure out that the timing was off — the code was simply struggling to respond to the faster machine. Continue reading “Swap The Clock Chip On The Mac SE/30 With An ATTiny85” →

A two picture montage of the blackout logger, the left picture being the front e-ink display of the data logger in a black case and the second picture of the back of the data logger, with the raspberry pi pico show attached to an e-ink display, both sitting on a wooden table.

Blackout Logger Keeps Track Of Power Outages

November 26, 2022 by Abe Connelly 7 Comments

[Dmytro Panin] lives in Kyiv, Ukraine where there have been rolling blackouts to stabilize the power grid. To help keep track of when the blackouts might happen, be they planned or emergency, and to get more information on how long the blackouts last, [Dmytro] has created a blackout logger.

The build consists of a Raspberry Pi Pico that connects to a DS3231 real time clock (RTC) with a Waveshare 3.7 inch eInk display which [Dmytro] puts into a custom 3D printed case. The RTC has it’s own small power supply, often times from a coin cell battery attached to the module, allowing it to keep time when the module and other devices attached to it are powered off.

The Raspberry Pi Pico is programmed to “poll” every 30 seconds, writing the current time to a file. Should the unit lose power, the last time, within a 30 second window, is available when power is restored and the unit wakes up again. Since the RTC has kept the current time, there is enough information to display the duration of the blackout. The eInk screen ensures that the information is readily available, even when there is no power.

War is not the only reason blackouts can occur and we’ve covered some issues with blackouts in Texas and California in the US.

Hackaday Prize 2022: Soviet Geiger Counter Gets WiFi

July 30, 2022 by Bryan Cockfield 4 Comments

[Marek] has an impressive collection of old Soviet-style Geiger counters. These are handy tools to have in some specific situations, but for most of us they would be curiosities. Even so, they need some help from the modern world to work well, and [Marek] has come up with some pretty creative ways of bringing them into the 21st century. This version, for example, adds WiFi capabilities.

This build is based on the STS-5 Geiger tube but the real heavy lifting is handled by an ESP8266 which also provides a wireless network connection. There are some limitations to using an ESP8266 to control a time-sensitive device like a Geiger tube, especially the lack of local storage, but [Marek] solves this problem by including a real-time clock and locally caching data until a network connection is re-established. Future plans for the device include adding temperature and atmospheric temperature sensors.

Eventually this Geiger counter will be installed in a watertight enclosure outside so [Marek] can keep an eye on the background radiation of his neighborhood. Previously he was doing this with another build, but that one only had access to the network over an Ethernet cable, so this one is quite an upgrade.

Careful Cuts Lets Logger Last A Year On A Coin Cell

March 14, 2022 by Bryan Cockfield 21 Comments

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.

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!

NTP Server Gets Time From Space

January 20, 2022 by Bryan Cockfield 30 Comments

Cheap GPS units are readily available nowadays, which is great if you have something that needs to be very precisely located. Finding the position of things is one of many uses for GPS, though. There are plenty of ways to take advantage of some of the ancillary tools that the GPS uses to determine location. In this case it’s using the precise timekeeping abilities of the satellites to build a microsecond-accurate network time protocol (NTP) server.

GPS works by triangulating position between a receiver and a number of satellites, but since the satellites are constantly moving an incredibly precise timing signal is needed in order to accurately determine location from all of these variables. This build simply teases out that time information from the satellite network and ignores the location data. There are only two parts to this build, a cheap GPS receiver and a Raspberry Pi, but [Austin] goes into great detail about how to set up the software side as well including installing PPS, GPSd, and then setting up the actual NTP server on the Pi.

While this is an excellent way to self-host your own NTP server if you don’t have Internet access (or just want to do it yourself), [Austin] does note that this is probably overkill on timekeeping as far as accuracy goes. On the other hand, the Raspberry Pi has no built-in real time clock of its own, so this might actually be a cost-competitive way of timekeeping even when compared to something more traditional like a DS3231 RTC module.

Continue reading “NTP Server Gets Time From Space” →

An orange 3D printed four digit clock with rotating segments

Be Mesmerized By The Latest Time Twister

December 18, 2021 by Chris Wilkinson 16 Comments

[Hans Andersson] has been creating marvelous twisting timepieces for over a decade, and we’re pleased to be able to share his latest mechanical clock contraption with our readers, the Time Twister 5.

In contrast to his previous LEGO-based clocks, version five of the Time Twister uses 3D printed segments, undoubtedly providing greater flexibility in terms of aesthetics and function. Each digit is a mechanical display, five layers vertical and three segments horizontal, with a total of three unique faces. Each layer of each display can be individually rotated by a servo, and this arrangement allows for displaying any number between zero and nine. The whole show is controlled by an Arduino MEGA and a DS3231 real-time clock.

Watching these upended prisms rotate into legible fifteen-segment digits is enjoyable enough already, but the mechanical sound created by this timepiece in motion is arguably even more satisfying. Check out the video below to see (and hear) for yourself. If you want to build one yourself, all the details are here.

We last covered [Hans Andersson] and his very first Time Twister clock way back in November 2011. Since then we’ve come across many impressive mechanical clocks, like this seven-segment work of art. We’re constantly impressed by the outstanding craftsmanship of these mechanical clocks, and it’s inspiring to see one of our OG horologists back in the saddle once more.

Continue reading “Be Mesmerized By The Latest Time Twister” →

Pomodoro timer helps you focus on tasks without burning out.

World’s Cutest Pomodoro Timer Is Also A Clock

October 29, 2021 by Kristina Panos 17 Comments

Student and hacker [prusteen] recently fell in love with the Pomodoro method of time management. That’s where you concentrate on your task for 25 minutes, then take a five-minute break, and repeat this four times with a longer break at the end. Initially, [prusteen] was keeping track on their phone, but hated having to change the timer value between Pomodoros and break times. In order to keep the flow mode engaged, [prusteen] came up with this darling little study buddy that does it all with the push of a button.

By default, this tomato shows the current time, which we think is a handy and often-overlooked feature of Pomodoro timer builds. Press that momentary switch on the front, and it starts counting upward to 25 minutes. Then it beeps in stereo through a pair of buzzers when the time is up, and automatically starts a five-minute break timer. Press it again and the display goes back to clock mode, although judging by the code, doing this will cancel the timer.

Inside the juicy enclosure is an Arduino Nano, an RTC, and a 7-segment display. We love the attention to detail here, from the little green leaves on top to the anatomically-correct dimple on the underside. And we always like to see lids that snap on with magnets. So satisfying. Check out the brief demo after the break, which unfortunately does not include any lid-snapping action.

Do you need more interaction with your Pomodoro timer? Build yourself a pomo-dachi instead.

Continue reading “World’s Cutest Pomodoro Timer Is Also A Clock” →