Internet-Connected TI-84


Just before the days where every high school student had a cell phone, everyone in class had a TI graphing calculator. In some ways this was better than a cell phone: If you wanted to play BlockDude instead of doing trig identities, this was much more discrete. The only downside is that the TI calculators can’t easily communicate to each other like cell phones can. [Christopher] has solved this problem with his latest project which provides Wi-Fi functionality to a TI graphing calculator, and has much greater aspirations than helping teenagers waste time in pre-calculus classes.

The boards are based around a Spark Core Wi-Fi development board which is (appropriately) built around a TI CC3000 chip and a STM32F103 microcontroller. The goal of the project is to connect the calculators directly to the Global CALCnet network without needing a separate computer as a go-between. These boards made it easy to get the original Arduino-based code modified and running on the new hardware.

After a TI-BASIC program is loaded on the graphing calculator, it is able to input the credentials for the LAN and access the internet where all kinds of great calculator resources are available through the Global CALCnet. This is a great project to make the math workhorse of the classroom even more useful to students. Or, if you’re bored with trig identities again, you can also run a port of DOOM.

Why Kickstarter projects are always delayed

Most Hackaday readers may remember the Spark Core, an Arduino-compatible, Wi-Fi enabled, cloud-powered development platform. Its Kickstarter campaign funding goal was 10k, but it ended up getting more than half a million. The founder and CEO of Spark [Zach Supalla] recently published an article explaining why Kickstarter projects are always delayed as the Spark core project currently is 7 weeks behind schedule.

[Zach] starts off by mentioning that most founders are optimistic, making them want to embark in this kind of adventure in the first place. In most presentation videos the prototypes shown are usually rougher than they appear, allowing the presenters to skip over the unfinished bits. Moreover, the transition from prototype to “manufacturable product ” also adds unexpected delays. For example, if a product has a plastic casing it is very easy to 3D print the prototype but much harder to setup a plastic injection system. Last, sourcing the components may get tricky as in the case of Spark core the quantities were quite important. Oddly enough, it was very hard for them to get the sparkcore CC3000 Wifi module.

Advanced Transcend WiFi SD Hacking: Custom Kernels, X, and Firefox


[Dmitry] read about hacking the Transcend WiFi cards, and decided to give it a try himself.   We already covered [Pablo's] work with the Transcend card. [Dmitry] took a different enough approach to warrant a second look.

Rather than work from the web interface and user scripts down, [Dmitry] decided to start from Transcend’s GPL package and work his way up. Unfortunately, he found that the package was woefully incomplete – putting the card firmly into the “violates GPL” category. Undaunted, [Dmitry] fired off some emails to the support staff and soldiered on.

It turns out the card uses u-boot to expand the kernel and basic file system into a ramdisk. Unfortunately the size is limited to 3MB. The limit is hard-coded into u-boot, the sources of which transcend didn’t include in the GPL package.

[Dmitry] was able to create his own binary image within the 3MB limit and load it on the card. He discovered a few very interesting (and scary) things. The flash file system must be formatted FAT32, or the controller will become very upset. The 16 (or 32)GB of flash is also mounted read/write to TWO operating systems. Linux on the SD card, and whatever host system the card happens to be plugged in to. This is dangerous to say the least. Any write to the flash could cause a collision leading to lost data – or even a completely corrupt file system. [Read more...]

Hacking Transcend Wifi SD Cards

[Pablo] is a recent and proud owner of a Transcend WiFi SD Card. It allows him to transfer his pictures to any  WiFi-enabled device in a matter of seconds.

As he suspected that some kind of Linux was running on it, he began to see if he could get a root access on it… and succeeded.

His clear and detailed write-up begins with explaining how a simple trick allowed him to browse through the card’s file system, which (as he guessed correctly) is running busybox. From there he was able to see if any of the poorly written Perl scripts had security holes… and got more than he bargained for.

He first thought he had found a way to make the embedded Linux launch user provided scripts and execute commands by making a special HTTP POST request… which failed due to a small technicality. His second attempt was a success: [Pablo] found that the user set password is directly entered in a Linux shell command. Therefore, the password “admin; echo haxx > /tmp/hi.txt #” could create a hi.txt text file.

From there things got easy. He just had to make the card download another busybox to use all the commands that were originally disabled in the card’s Linux. In the end he got the card to connect a bash to his computer so he could launch every command he wanted.

As it was not enough, [Pablo] even discovered an easy way to find the current password of the card. Talk about security…

Hackaday Links: September 15, 2011

Open-source Mars rover

[Seth King] wasn’t satisfied with current robotics platforms that don’t work well outdoors. He started the Open Rover Kickstarter with the end goal of having a 6-wheel robot with a rocker-bogie suspension just like the Mars landers. We’re sure it’ll be an interesting platform.

Adding a Flash to a key fob video camera

[doctormord] picked up a key fob “spycam” and was surprised that there wasn’t any onboard illumination. Then again, that would probably defeat the purpose of the “spycam.” A transistor, LED and resistor later (translation), he had a camera with a light. Pics here.

Automated WEP cracking

This is a video of [Elliott] using his autocrack script to crack a WEP wi-fi network. It took [Elliott] less than a minute to crack a network he set up. Lesson: don’t use WEP.

Adding wi-fi to a laptop the fast way

This laptop used to have a broken Mini-PCIe wi-fi adapter. [Mikko] fixed the wireless by taking out the old card and hooking up a USB wi-fi adapter. He soldered the USB leads directly to the back of an internal USB port and used hot glue “to prevent bad things from happening.” A very easy, fast, and cheap way of fixing a broken wireless adapter.

Han Solo’s soldering iron

When [Craig] was 15, he broke the Bakelite casing of his father’s soldering iron. Being a good son, he fixed it by gutting his original Star Wars Han Solo blaster. Nice, but not as great as Starsong from My Little Pony.

Eye-Fi Explore review

The WiFi uploading Eye-Fi SD card made a big splash when it was first introduced, but now Eye-Fi has a whole line of different products. The top of the line is the Eye-Fi Explore, which supports geotagging without using a GPS. Instead of GPS hardware, it uses the Skyhook Wireless Wi-Fi Postitioning System, which correlates the position of the Eye-Fi’s access point to GPS locations, creating virtual GPS functionality. This allows photos taken with the Eye-Fi to be be geotagged. Of course, the accuracy of the system is noticeably lower than true GPS and seems to be affected by a number of external factors, but it is still accurate enough to tag the photo within the immediate vicinity of where it was taken.

WiFi positioning is great feature, but certainly not limited to photography. Since the Eye-Fi is at its core SD storage media, you could probably have it geotag data saved to the card, even if it wasn’t created by a digital camera..

In car WiFi

You may have already heard that Chrysler is planning to provide in-car wireless internet access to its vehicles. If not, expect to hear more about it later this year when the requisite hardware becomes a sales-floor option, or next year when it becomes factory standard for some cars.

We can’t say it’s a bad idea, it’s just not a new one. Plenty of commercial portable routers are available, but they still need a modem and data plan to provide internet access. For internet access and wireless routing, look to [Nate True]‘s cellphone-router combo, which uses a spare Nokia cellphone and a highly modded Wi-Fi router running OpenWRT. [True] has made it easy by providing the instructions and necessary custom code, but it seems like a lot of effort for a relatively slow connection. We think the original Stompbox is still the most fun since it has the speed of commercial devices and an open x86 OS to modify.


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