A recent project over on Hackaday.io from [Michael Gardi] is Trekulator – Where No Maker Has Gone Before.

This is a fun build and [Michael] has done a very good job of emulating the original device. [Michael] used the Hackaday.io logging feature to log his progress. Starting in September 2024 he modeled the case, got his original hardware working, got the 7-segment display working, added support for sound, got the keypad working and mounted it, added the TFT display and mounted it, wired up the breadboard implementation, designed and implemented the PCBs, added some finishing touches, installed improved keys, and added a power socket back in March.

It is perhaps funny that where the original device used four red LEDs, [Michael] has used an entire TFT display. This would have been pure decadence by the standards of 1977. The software for the ESP32 microcontroller was fairly involved. It had to support audio, graphics, animations, keyboard input, the 7-segment display, and the actual calculations.

The calculations are done using double-precision floating-point values and eight positions on the display so this code will do weird things in some edge cases. For instance if you ask it to sum two eight digit numbers as 90,000,000 and 80,000,000, which would ordinarily sum to the nine digit value 170,000,000, the display will show you a different value instead, such as maybe 17,000,000 or 70,000,000. Why don’t you put one together and let us know what it actually does! Also, can you find any floating-point precision bugs?

This was a really fun project, thanks to [Michael] for writing it up and letting us know via the tips line!

Do you like scientific calculators? Don’t bother answering that question, you’re reading Hackaday so we already know the answer. We also know you’re a fan of building things yourself and open source, which makes us fairly sure you’ll be just as interested in the recently announced ClockworkPi PicoCalc as we are.

On the surface, it looks like a chunky scientific calculator, though on further inspection you’ll note it comes equipped with a QWERTY keyboard. But open up the case and what you’ve really got is an elaborate carrier board for the Raspberry Pi Pico. The PicoCalc supports all variants of the microcontroller, but realistically we can’t think of any reason that you wouldn’t just use the latest version.

With the MCU connected, you’ll have access to the PicoCalc’s 320×320 4-inch IPS screen, backlit I2C-connected keyboard, SD card slot, 8 MB PSRAM, and dual PWM speakers. Power is provided by a pair of 18650 cells (which you’ll need to supply on your own), and the board has the necessary circuitry to charge them up over USB-C.

Everything is housed in an injection molded case, but the project page says all the necessary CAD files will be eventually be released under the GPL v3 so you can 3D print or CNC your own enclosure. For now though, the only thing of note that seems to be in the PicoCalc GitHub repository is a PCB schematic.

The software side of things is a little less clear. The page mentions a BASIC interpreter, MP3 playback, and support for various programming languages, but we get the impression that’s just a list of stuff you can run on the Pi Pico. There are a few images that clearly show the PicoCalc actually being used as a calculator however, so there may be an official firmware yet to be revealed.

The PicoCalc kit is on sale now, and will set you back $75 USD — which actually includes a first-generation Pi Pico, on the off chance that you don’t already have a few laying around. We’ve been impressed with the previous offerings from ClockworkPi, so assuming this new kit maintains that same build quality, it seems like a fair enough price.