Running A Web Server On The ESP8266

November 15, 2014 by Ethan Zonca 20 Comments

We’ve written lot about the ESP8266 lately, but people keep finding more awesome uses for this inexpensive module. [Martin] decided that using the ESP8266 with an external microcontroller was overkill, and decided to implement his project entirely on the module with a built-in web server.

[Martin] started out with the ESP8266 web server firmware developed by [sprite_tm]. This firmware provides a basic web server that supports multiple connections and simple CGI scripts right on the module. The web server firmware opens up a ton of possibilities with CGI scripting. When booting up in AP mode, you can even connect the ESP8266 to another access point right from the your browser.

[Martin] decided to connect a DHT22 temperature/humidity sensor to the module as a proof of concept. He used a DHT22 library written for the ESP8266 to read data from the sensor, and wrote a CGI script to display the data on a web page. [Martin] also added buttons to control a GPIO pin as a proof of concept. He posted his source code and a binary (see the end of his post) so you can try out his application and mod it for your own project.

Programming An Arduino Over WiFi With The ESP8266

November 13, 2014 by Ethan Zonca 16 Comments

A lot of people have used ESP8266 to add inexpensive WiFi connectivity to their projects, but [Oscar] decided to take it one step further and program an Arduino over WiFi with the ESP8266. [Oscar] wrote a server script in Python that communicates with firmware running on the Arduino. The Arduino connects to the server on startup and listens for a “reboot” command.

When the command is received, the processor resets and enters the bootloader. The python script begins streaming a hex file over WiFi to the ESP8226, which relays it to the Arduino’s bootloader. Once the hex file is streamed, the microcontroller seamlessly starts executing the firmware. This method can be used with any AVR running a stk500-compatible bootloader.

[Oscar]’s writeup is in Spanish, but fortunately the comments in his Python and Arduino code are in English. Check out the video (in English) after the break where [Oscar] demonstrates his bootloading setup.

Continue reading “Programming An Arduino Over WiFi With The ESP8266” →

Using Router SoCs As WiFi Modules (Yet Again)

November 6, 2014 by Brian Benchoff 34 Comments

8-bit AVRs and 32-bit ARMs do one thing, and one thing well: controlling other electronics and sensors while sipping power. The Internet of Things is upon us and with that comes the need for connecting to WiFi networks. Already, a lot of chips are using repackaged System on Chips to provide an easy way to connect to WiFi, and the USR-WIFI232-T is the latest of the bunch. It’s yet another UART to WiFi bridge, and as [2XOD], it’s pretty easy to connect to an AVR.

The module in question can be had through the usual channels for about $11, shipped straight from China, and the only purpose of this device is to provide a bridge between a serial port and a wireless network. They’re not that powerful, and are only meant for simple tasks,

[2XOD] got his hands on one of these modules and tested them out. They’re actually somewhat interesting, with all the configuration happening over a webpage served from the device. Of course the standard AT commands are available for setting everything up, just like the ESP8266.

With a month of testing, [2XOD] has found this to be a very reliable device, logging temperatures every minute for two weeks. There’s also a breakout board available to make connection easy, and depending on what project you’re building, these could be a reasonable stand-in for some other popular UART -> WiFi chips.

A Development Board For The ESP8266

November 5, 2014 by Brian Benchoff 44 Comments

[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.

An ESP8266 Based Smartmeter

November 2, 2014 by Mathieu Stephan 17 Comments

During these last weeks we’ve been talking a lot about the ESP8266, a $4 microcontroller based Wifi module. As the SDK was recently released by Espressif a lot of cheap Internet of Things applications were made possible.

[Thomas] used one module to make a simple smartmeter measuring the active time of his heater together with the outside temperature. He added 2 AT commands starting/stopping the logging process and used one GPIO pin to monitor the heater’s oil pump state. The measurements are then periodically pushed via a TCP connection to his data collecting server, which allows him to generate nice graphs.

In the video embedded below you’ll see [Thomas] demoing his system. On his hackaday.io project page he put up a very detailed explanation on how to replicate his awesome project. All the resources he used and create can also be downloaded on the project’s GitHub page.

Continue reading “An ESP8266 Based Smartmeter” →

Reverse Engineering The D-Link WPS Pin Algorithm

October 31, 2014 by Brian Benchoff 36 Comments

A router with WPS requires a PIN to allow other devices to connect, and this PIN should be unique to every router and not derived from other easily accessible data found on the router. When [Craig] took a look at the firmware of a D-Link DIR-810L 802.11ac router, he found exactly the opposite; the WPS PIN was easily decipherable because it was generated entirely from the router’s MAC address and could be reverse engineered by sniffing WiFi.

When [Craig] was taking a look at the disassembled firmware from his router, he noticed a bit of code that accessed the NVRAM used for storing device-specific information like a serial number. This bit of code wasn’t retrieving a WPS pin, but the WAN MAC address instead. Instead of being unique to each device and opaque to every other bit of data on the router, the WPS pin was simply generated (with a bit of math) from the MAC address. This means anyone upstream of the router can easily derive the WPS pin of the router, and essentially gives everyone the keys to the castle of this router.

A few years ago, it was discovered the WPS pin was extremely insecure anyway, able to be brute-forced in a matter of minutes. There are patches router manufacturers could apply to detect these brute force attacks, closing that vulnerability. [Craig]’s code, though, demonstrates that a very large number of D-Link routers effectively broadcast their WPS PIN to the world. To make things even worse, the BSSID found in every wireless frame is also derived from the WAN MAC address. [Craig] has literally broken WPS on a huge number of D-Link routers, thanks to a single engineer that decided to generate the WPS PIN from the MAC address.

[Craig] has an incomplete list of routers that are confirmed affected on his site, along with a list of confirmed unaffected routers.

An SDK For The ESP8266 WiFi Chip

October 25, 2014 by Brian Benchoff 70 Comments

The ESP8266 is a chip that turned a lot of heads recently, stuffing a WiFi radio, TCP/IP stack, and all the required bits to get a microcontroller on the Internet into a tiny, $5 module. It’s an interesting chip, not only because it’s a UART to WiFi module, allowing nearly anything to get on the Internet for $5, but because there’s a user-programmable microcontroller in this board. If only we had an SDK or a few libraries…

The ESP8266 SDK is finally here. A complete SDK for the ESP8266 was just posted to the Expressif forums, along with a VirtualBox image with Ubuntu that includes GCC for the LX106 core used in this module.

Included in the SDK are sources for an SSL, JSON, and lwIP library, making this a solution for pretty much everything you would need to do with an Internet of Things thing. As far as LX106 core is concerned, there’s example code for using the spare pins on this board as GPIOs, I2C and SPI busses, and a UART.

This turns the ESP8266 into something much better than a UART to WiFi module; now you can create a Internet of Things thing with just $5 in hardware. We’d love to see some examples, so put those up on hackaday.io and send them in to the tip line.