A Development Board for the ESP8266

[Necromant] is ready to dip his toes into the world of firmware development for everyone’s favorite WiFi chip, the ESP8266. Before that begins, it would be a good idea to make a nifty little breakout board for this chip. Here it is, a board with a USB to UART converter with board art that’s compatible with a toner transfer process.

Since this is just a board that turns USB into something the ESP8266 can understand, the most reasonable course of action would be to throw an FTDI chip in there and call it a day. We wouldn’t suggest that. Instead, [necromant] is using a Prolific PL2303HX. The RTS/DTR pins on the serial chip aren’t used, but only because the ESP8266 forums haven’t yet decided on how to connect them to the WiFi chip. GPIOs on the Prolific are broken out for some other projects [necromant] has in mind, with a userspace driver to make everything work.

[Necromant] is the creator of Antares, a build system for microcontrollers and a Hackaday Prize entry. He intends to make his build system compatible with this WiFi chip, just as soon as everyone else figures out an easy way to make it work.

Using a Headphone Jack as a UART

We’ve seen audio ports being used to establish a communications channel between a computer and a microcontroller before, but nothing quite as slick as this. [Gordon] is using a webpage running on a tablet to send Javascript to a microcontroller where the entire program is interpreted.

[Gordon] is using the Espruino Pico, a board that’s on Kickstarter right now. This tiny board is built around a javascript interpreter, allowing code to be written and updated on the fly without mucking around with bootloaders.

This technique can be expanded to provide bidriectional communication between a microcontroller and a computer. On the project Github, [Gordon] used the microphone pin on a TRRS jack to sent data to a computer. It needs two more resistors, but other than that, it’s as simple as the one-way communications setup.

[Gordon] put together a few demos of the program, including one that will change the color of some RGB LEDs in response to input on a webpage.

Continue reading “Using a Headphone Jack as a UART”

Checking Email With The ESP8266

Ever so slowly, everyone’s favorite WiFi adapter is making its way into Internet-enabled projects. [jimeer01] created a device that reads the subject and sender lines from the latest email in his inbox and displays it on an LCD using the ESP8266 WiFi chip.

[jimeer] is using a ByPic for writing to the LCD and querying an inbox through an ESP8266 module. The ByPic is a board built around the BV_Basic firmware, stuffing a PIC microcontroller in an Arduino form factor and giving it a BASIC interpreter. Because this board isn’t ‘compile and flash’ like an Arduino, it’s perfectly suited for changing WiFi configurations and IMAP server credentials on the fly.

The device grabs the latest email in an inbox and displays the date, sender, and subject on the display. After scrolling through those lines, the PIC hits the ESP8266 to query the server again, grabbing the latest email, and repeating the whole process again, all without needing to connect the device to a computer. Video below.

Continue reading “Checking Email With The ESP8266″

Improving the Parallax Propeller in an FPGA

The Parallax Propeller is an interesting chip that doesn’t get a lot of love, but since the entire chip was released as open source, that might be about to change: people are putting this chip inside FPGA and modifying the binaries to give the chip functions that never existed in the original.

Last August, Parallax released the source for the P8X32A, giving anyone with an FPGA board the ability to try out the Prop for their own designs. Since then, a few people have put some time in, cleaning up the files, unscrambling ROM images, fixing bugs, and all the general maintenance that an open source microcontroller core requires.

[Sylwester] has grabbed some of the experimental changes found on the Parallax forum and included them as a branch of the Propeller source. There is support for a second 32-bit port, giving the new chip 64 I/O pins, multiply instructions, video generators, hard-coded SD card libraries, and a variant called a microProp that has four cores instead of eight.

You can grab all the updated sources right here and load them up on a DE0 Nano FPGA board. If you’re exceptionally lucky and have the Altera DE2-115 dev board, you’ll also be able to run the upcoming Propeller 2.

Another Internet of Things Board (But This One Has Lisp))

Using routers as dev boards has been a long and cherished tradition in the circles we frequent, and finally design houses in China are taking notice. There have been a few ‘Internet of Things’ boards in recent months that have taken the SoC found in low-end routers, packaged the on a board with USB, some GPIOs, and a fair bit of memory and called it a dev board. The ZERO Plus is not an exception to this trend, but it does include a very interesting feature when it comes to the development environment: this one uses Lisp as its native language.

The Zero Plus is pretty much what you would expect from a router SoC being transplanted to an Internet of Things board: it uses the Ralink RT5350 SoC, giving it 802.11b/g/n, has 32MB of RAM, 8 or 16 M of Flash, I2C, I2S, SPI, USB, two UARTs, and 14 GPIOs. There is support for a webcam, temperature and humidity sensor, displays, and Arduino via a breakout board that appears to contain a standard, DIP-sized ATMega328,

All of that could be found in dozens of other boards, though. What really sets this one apart is the Lisp development environment. Programming the Zero is exactly as elegant as you would expect, with a ‘toggle a LED according to what time it is’ program looking something like this:

(define LED_On (lambda ()(dev.gpio 11 “out” 1)))
(define LED_Off (lambda ()(dev.gpio 11 “out” 0)))
(define CurrentTime? (lambda ()
      (int (time.strftime “%H” (time.localtime (time.time))))))
(define Night?
      (lambda ()
                  (> ( CurrentTime? ) 16) (< ( CurrentTime? ) 23)
(if (Night?) (LED_On) (LED_Off)

Dev boards built around somewhat more esoteric programming language isn’t anything new; The Espruino brings Javascript to ARM microcontrollers, and the MicroPython project is an astonishing undertaking and successful Kickstarter that brings the BASIC for the 21st century to the embedded world. Lisp, though… I don’t think anyone expected that. It’s a great way to differentiate your product, though.

Turning the DEFCON Badge Into a Bitcoin Miner


The DEFCON badge this year was an impressive piece of hardware, complete with mind-bending puzzles, cap sense buttons, LEDs, and of course a Parallax Propeller. [mike] thought a chip as cool as the Propeller should be put to better use than just sitting around until next year so he turned it into a Bitcoin miner, netting him an astonishing 40 hashes per second.

Mining Bitcoins on hardware that doesn’t have much processing power to begin with (at least compared to the FPGAs and ASIC miners commonly used) meant [mike] would have to find some interesting ways to compute the SHA256 hashes that mining requires. He turned to RetroMiner, the Bitcoin miner made for an original Nintendo. Like the NES miner, [mike] is offloading the communication with the Bitcoin network to a host computer, but all of the actual math is handled by a single core on the Propeller.

Saving one core for communication with the host computer, a DEFCON badge could conceivably manage 280 hashes/second, meaning the processing power of all the badges made for DEFCON is about equal to a seven-year-old graphics card.

Function Generator with Zero CPU Cycles

No one is sitting around their workbench trying to come up with the next great oscilloscope or multimeter, but function generators still remain one of the pieces of test equipment anyone – even someone with an Arduino starter pack – can build at home. Most of these function generators aren’t very good; you’re lucky if you can get a sine wave above the audio spectrum. [Bruce Land] had the idea to play around with DMA channels on a PIC32 and ended up with a function generator that uses zero CPU cycles. It’s perfect for a homebrew function generator build, or even a very cool audio synthesizer.

The main obstacles to generating a good sine wave at high frequencies are a high sample rate and an accurate DAC. For homebrew function generators, it’s usually the sample rate that’s terrible; it’s hard pushing bits out a port that fast. By using the DMA channel on a PIC32, [Bruce] can shove arbitrary waveforms out of the chip without using any CPU cycles. By writing a sine wave, or any other wave for that matter, to memory, the PIC32 will just spit them out and leave the CPU to do more important work.

[Bruce] was able to generate a great-looking sine wave up to 200 kHz, and the highest amplitude of the harmonics was about 40db below the fundamental up to 100 kHz. That’s a spectacular sine wave, and the perfect basis for a DIY function generator build.