Hacking an SD Slot for WiFi

Back in the 1990’s moving files via a floppy disk was known as “sneaker net.” While floppies are a thing of the past, SD Cards are the modern equivalent and they still lend themselves to sneaker net operations.

But why? WiFi is everywhere now. Wouldn’t it be great if you could hack those devices with SD slots to use WiFi? Apparently 3D printer [extrud3d] thought the same thing and found a way to reconfigure a Toshiba FlashAir card to put his 3D printer on the network.

The card is aimed at consumers, so by default it creates a hotspot and waits for a connection, a rudimentary web app allows you to move files back and forth over the network to the SD card which is then read by the host device. However, [extrud3d] shows how to modify a file on the SD card’s file system to allow the device to hook up to an existing wireless network and also provides a Python script to make the file transfer easier.

Although this hack is for a 3D printer, it ought to work with most devices that have a full sized SD slot (or can be adapted to take a full sized card). Since the hack is nothing more than changing a text file, it is a lot easier than some other SD hacks we’ve covered. Over on hackaday.io, [Chris Jones] has recently done some hacking on the FlashAir and has a list of its shell commands if you want to go beyond the text file hacks.

Continue reading “Hacking an SD Slot for WiFi”

Alarm Notifies the Office When the Coffee is Ready

[Stian] thought it would be nice if his coworkers could be electronically notified when the latest batch of coffee is ready. He ended up building an inexpensive coffee alarm system to do exactly that. When the coffee is done, the brewer can press a giant button to notify the rest of the office that it’s time for a cuppa joe.

[Stian’s] first project requirement was to activate the system using a big physical button. He chose a button from Sparkfun, although he ended up modifying it to better suit his needs. The original button came with a single LED built-in. This wasn’t enough for [Stian], so he added two more LEDs. All three LEDs are driven by a ULN2003A NPN transistor array. Now he can flash them in sequence to make a simple animation.

This momentary push button supplies power to a ESP8266 microcontroller using a soft latch power switch. When the momentary switch is pressed, it supplies power to the latch. The latch then powers up the main circuit and continues supplying power even when the push button is released. The reason for this power trickery is to conserve power from the 18650 li-on battery.

The core functionality of the alarm uses a combination of physical hardware and two cloud-based services. The ESP8266 was chosen because it includes a built-in WiFi chip and it only costs five dollars. The microcontroller is configured to connect to the WiFi network with the push of a button. The device also monitors the giant alarm button.

When the button is pressed, it sends an HTTP request to a custom clojure app running on a cloud service called Heroku. The clojure app then stores brewing information in a database and sends a notification to the Slack cloud service. Slack is a sort of project management app that allows multiple users to work on projects and communicate easier over the internet. [Stian] has tapped into it in order to send the actual text notification to his coworkers to let them know that the coffee is ready. Be sure to watch the demo video below. Continue reading “Alarm Notifies the Office When the Coffee is Ready”

New Part Day: The ESP8266 Killer

Around this time last year we first heard of the ESP8266 WiFi module. It’s still a great little module, providing WiFi connectivity for all those Internet of Things things at a price point of just $5. It’s an attractive price for a great module with a huge community pumping out a lot of projects for the platform.

Now there’s a new kid on the block. It’s called the EMW3165, and like the ESP it provides WiFi connectivity for a bunch of wireless projects. It’s much, much more capable with an STM32F4 ARM Coretex M4 microcontroller, a ‘self hosted’ networking library, more RAM, more Flash, and more GPIOs. How much, you’re probably asking yourself. It’s a dollar more than the ESP8266.

The datasheet for the module goes over all the gritty details. While this chip has 3.6V I/Os, there are some 5V tolerant pins – a boon for the Arduino crowd. It’s also surprisingly low power for something that connects to an 802.11n network. The real bonus here is the STM32F4 core – that’s a very, very powerful microcontroller, and if you want a 2-component WiFi webcam build, this is the part you should use. There will be a lot of interesting builds using this part. It’s also passed FCC certification. Very cool.

DNS Tunneling with an ESP8266

There’s a big problem with the Internet of Things. Everything’s just fine if your Things are happy to sit around your living room all day, where the WiFi gets four bars. But what does your poor Thing do when it wants to go out and get a coffee and it runs into a for-pay hotspot?

[Yakamo]’s solution is for your Thing to do the same thing you would: tunnel your data through DNS requests. It’s by no means a new idea, but the combination of DNS tunneling and IoT devices stands to be as great as peanut butter and chocolate.

DNS tunneling, in short, relies on you setting up your own DNS server with a dedicated subdomain and software that will handle generic data instead of information about IP addresses. You, or your Thing, send data encoded in “domain names” for it to look up, and the server passes data back to you in the response.

DNS tunneling is relatively slow because all data must be shoe-horned into “domain names” that can’t be too long. But it’s just right for your Thing to send its data reports back home while it’s out on its adventure.

Oh yeah. DNS tunneling may violate the terms and conditions of whatever hotspot is being accessed. Your Thing may want to consult its lawyer before trying this out in the world.

Wifibroadcast Makes WiFi FPV Video More Like Analog

Normal WiFi is not what you want to send video from your quadcopter back to the first-person-view (FPV) goggles strapped on your head, because it’s designed for 100% correct, two-way transmission of data between just two radios. Transmission of analog video signals, on the other hand, is lossy, one-way, and one-to-many, which is why the longer-range FPV flights all tend to use old-school analog video transmission.

When you’re near the edge of your radios’ range, you care much more about getting any image in a timely fashion than about getting the entire video sequence correctly after a delay. While WiFi is retransmitting packets and your video is buffering, your quadcopter is crashing, and you don’t need every video frame to be perfect in order to get an idea of how to save it. And finally, it’s just a lot easier to optimize both ends of a one-way transmission system than it is to build antennas that must receive and transmit symmetrically.

And that’s why [Befinitiv] wrote wifibroadcast: to give his WiFi FPV video system some of the virtues of analog broadcast.

Continue reading “Wifibroadcast Makes WiFi FPV Video More Like Analog”

DIY ESP8266 Development Board

Those small, super-cheap, ESP8266 modules are being installed everywhere, creating all sorts of frivolous internet connected thingamajigs. But consider this period as a training ground of sorts, as hackers smarten their chops on figuring out how to get the best out of this IoT gravy train. Right now, getting the ESP8266 to work requires a fair amount of work and to make things easier, [Abdulgafur] built a ESP8266 development board.

The dev board lets the user connect the ESP8266 to a PIC micro controller as well as to a host PC. In addition, it hosts several peripherals such as a 2×16 LCD display, 4 push buttons, couple of indicator LEDs and some GPIO’s broken out to a header. PC communication is via a FT232RL USB-UART converter over a Mini-USB connector. There’s also a few bi-directional level converters to translate between 5V and 3.3V and pull-up resistors for the ESP8266.

As of now, the dev board only supports the ESP8266-01 module. A nice upgrade would be to add support for other ESP8266 modules too. Maybe a separate, 3d printed, pogo pinned, test fixture for the other modules. If you plan to build you own version, [Abdulgafur] has the schematic, PCB and BoM available for download, although we couldn’t spot the PIC code, so you might have to ask for that. And it would be a good idea to remove the GND copper pour from under the ESP8266 footprint.

Hackaday Prize Entry: The MultiSpork

If you’re working on a mobile project – a robot, something outside, or even your car – you don’t want to bring an oscilloscope, logic analyzer, signal generator, or any other piece of equipment that should stay on the bench. For his Hackaday Prize Entry, [Pierce Nichols] is working on the electronic equivalent of a Leatherman: something small and portable that also does just enough to get by in a pinch.

The MultiSpork, as [Pierce] calls his device, is a single WiFi enabled board that’s completely portable. With the addition of a $50 Android tablet, it’s very close to a complete electronics lab in a box.

The heart of the MultiSpork is a new chip from Maxim, the MAX 11300. This chip has 20 pins that can be used as a 12-bit ADC, a 12-bit DAC, or as GPIOs. it’s a logic analyzer, signal generator, oscilloscope, and a Bus Pirate in a single chip. As far as the rest of the board goes, [Pierce] is forgoing any notion of a hardware freeze and changing the Atmel microcontroller over to a TI CC3200 chip that will be coming out soon.

[Pierce] put together a short video describing the MultiSpork; you can check that out below.


The 2015 Hackaday Prize is sponsored by:

Continue reading “Hackaday Prize Entry: The MultiSpork”