A Calculator with Free Software and Open Hardware

We’re fond of open source things here. Whether it’s 3D printers, circuit modeling software, or a global network of satellite base stations, the more open it is the more it improves the world around us. [Pierre Parent] and [Ael Gain] have certainly taken these values to heart with their open handheld graphing calculator.

While the duo isn’t giving away the calculators themselves, they are releasing all of the hardware designs so that anyone can build this calculator. It’s based on a imx233 processor because this chip (and most everything else about this calculator) is easy to source and easy to use. That, and there is a lot of documentation on it that is in the public domain. All of the designs, including the circuit board and CAD files for the case, are available to anyone who is curious, or wants to build their own.

The software on the calculator (and the software that was used to design the calculator) is all free software too. The calculator runs Linux (of course) and a free TI simulator environment in the hopes of easing the transition of anyone who grew up using TI’s graphing calculators. The project is still in a prototype phase, but it looks very promising. Even though the calculator can already run Pokemon, maybe one day it will even be able to run Super Smash Bros as well!

Running Debian on a Graphing Calculator

While the ubiquitous TI-83 still runs off an ancient Zilog Z80 processor, the newer TI-Nspire series of graphing calculators uses modern ARM devices. [Codinghobbit] managed to get Debian Linux running on a TI-Nspire calculator, and has written a guide explaining how it’s done.

The process uses Ndless, a jailbreak which allows code to run at a low level on the device. Ndless also includes a full SDK, emulator, and debugger for developing apps. In this case, Ndless is used to load the Linux kernel.

The root filesystem is built on a PC using debootstrap and the QEMU ARM emulator. This allows you to install whatever packages are needed via apt, before transitioning to the calculator itself.

With the root filesystem on a USB flash drive, Ndless runs the Linux loader, which starts the kernel, mounts the root filesystem, and boots in to a Debian system in about two minutes. As the video after the break demonstrates, this leaves you with a shell on the calculator. We’re not exactly sure what to do with Linux on a graphing calculator, but it is a neat demonstration.

Continue reading “Running Debian on a Graphing Calculator”

Super Smash Bros on a Calculator

Move over, BlockDude! There’s a new calculator game in town. [Hayleia] and a few other programmers have been hard at work on a clone of Super Smash Bros for graphing calculators that is sure to keep you busy in your next calculus class.

The game, called Smash Bros Open, is based on the Nintendo fighting game and is written specifically for monochrome z80 calculators (the TI-83 and TI-84 being the most ubiquitous of these). The game runs in 6 MHz mode with a simple background, or it can run in 15 MHz mode with a more complicated background. The programmers intend for the game to be open source, so that anyone can add anything to the games that they want, with the hopes of making the game true to its namesake.

Anyone who is looking to download a copy of this should know that Smash Bros Open is currently a work-in-progress. Right now both players need to play on the same calculator (with different keys), and Fox is the only playable character. The programmers hope to resolve the two player issue by using a second calculator as a game pad, or by linking the two calculators using Global CalcNet. As for the other characters, those can be added by others based on the existing code which is available on the project’s forum post!

Thanks to [Chris] for the tip.

Phoenard, A Prototyping Gadget

The Hackaday Prize party wasn’t just about the five finalists; actually, there were more THP entries in attendance – All Yarns Are Beautiful, OpenExposer, M.A.R.S., a 3D scanner, and a few more that I’m forgetting – than actual finalists. In addition, a number of people brought projects that had never seen the light of day, like [Ralf] and [Pamungkas]’ Phoenard.

Phoenard is a Kickstarter project the guys launched at the prize party, something they could attend as a little side trip after manning the ‘maker’ part of the Atmel booth at Electronica. They’ve come up with a tiny handheld device that can only be described as a ‘gadget’. It has a touchscreen, a battery, an MegaAVR, a few connectors, and not much else. What makes this project cool is how they’re running their applications. A bootloader sits on the AVR, but all the applications – everything from a GSM phone to an MP3 player – lives on a microSD card.

The Phoenard guys have come up with a few expansion modules for Bluetooth LE, GSM, GPS, and all the usual cool modules. Plugging one of these modules into the back of the device adds capability, and if that isn’t enough, there’s an old 30-pin iPhone connector on the bottom ready to accept a prototyping board.

Video of these guys below.

Continue reading “Phoenard, A Prototyping Gadget”

Game Tin: Handheld Games with no Batteries

Anyone who grew up with a Game Boy knows how well they sucked through AA batteries. [Nick]’s Game Tin console solves this problem by running of an ultracapacitor charged by solar power.

The console is based on a EFM32 microcontroller: an ARM device designed for low power applications. The 128×128 pixel monochrome memory display provides low-fi graphics while maintaining low power consumption.

There’s two solar cells and a BQ25570 energy harvesting IC to charge the ultracap. This chip takes care of maximum power point tracking to get the most out of the solar cells. If it’s dark out, the device can be charged in about 30 seconds by connecting USB power.

The 10 F Maxwell ultracapacitor can run a game on the device for 1.5 hours without sunlight, and the device runs indefinitely in the sun. Thanks to the memory display, applications that have lower refresh rates will have much lower power consumption.

The Game Tin is open source, and is being developed using KiCad. You can grab all the EDA files from Bitbucket. [Nick] is also gauging interest in the Game Tin, and hopes to release it as a kit.

Kruger’s Zippo Remote

FWHLN99HZ2IV5DF.MEDIUM

Inspired by the detonator in the Captain America: The First Avenger movie, [Jon] modified a normal Zippo lighter to activate a relay on a receiver module. His instructables shows how to create such a device by adjusting the insert in such a way that if someone flipped it open, all they would see would be a flint wheel, flint, wick, and all that stuff; nothing would be abnormal. In order to do this, the components would have to be perfectly concealed.

To acquire a remote signal, [Jon] used the whole metal case as an antenna instead of replacing the wick with one. An antenna pin on an RF module was attached to the insert to get the necessary effect. The flint wheel was then turned into a button and a notification LED was installed. Once the code was uploaded and a receiver module was fashioned together, the end product produced a flash of sparks on the other end.

This hack was made for educational use, and is only meant for demonstration purposes.

Continue reading “Kruger’s Zippo Remote”

Reverse Engineering a GPS Watch to Upload Custom Firmware

 

Sometimes GPS watches are too good to be left with their stock firmware. [Renaud] opened his Kalenji 300 GPS watch, reverse engineered it in order to upload his own custom firmware.

The first step was to sniff the serial traffic between the PC and the microcontroller when upgrading firmware to understand the protocol and commands used. [Renaud] then opened the watch, figured out what the different test points and components were. He used his buspirate with OpenOCD to extract the existing STM32F103 firmware. The firmware helped him find the proper value to store in a dedicated register for the boot loader to start.

By looking at the disassembly code he also found the SPI LCD initialization sequence and discovered that it uses a controller similar to the ST7571. He finally compiled his own program which uses the u8glib graphics library. Follow us after the break for the demonstration video.

Continue reading “Reverse Engineering a GPS Watch to Upload Custom Firmware”