Tag Archives: wireless hacks

An ESP8266 Based Smartmeter

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ESP8266 based monitoring

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.

Filed under: hardware, wireless hacks

New Chip Alert: The ESP8266 WiFi Module (It’s $5)

via Hackaday » » hardware


Every so often we run across something in the Hackaday tip line that sends us scurrying to Google, trying to source a component, part, or assembly. The ESP8266 WiFi module is the latest, made interesting because it pretty much doesn’t exist outside China.

Why is it cool? It’s a WiFi module with an SOC, making it somewhat similar to TI’s CC300 in conception (A.K.A. the thing that makes the Spark Core so appealing), in that a microcontroller on the module takes care of all the WiFi, TCP/IP stack, and the overhead found in an 802.11 network. It’s addressable over SPI and UART, making this an exceptionally easy choice for anyone wanting to build an Internet of Things thing; you can simply connect any microcontroller to this module and start pushing data up to the Internet. Oh, it’s also being sold for $5 in quantity one. Yes, for five dollars you can blink a LED from the Internet. That’s about half the price as the CC3000 itself, and a quarter of the price if you were to build a CC3000 breakout board.

There’s a catch, right, there’s always a catch. Yep. About two hours after this post is published it will be the number one English language Google result for “ESP8266.” As far as the English-speaking world is concerned, there is absolutely nothing to be found anywhere on the Internet on this module.

Seeed Studio recently sold a few of these modules for $7 and has some documentation, including a full datasheet and an AT command set. All the documentation is in Chinese. There’s also an “ESP8266 IoT SDK”, but from a quick glance at the code, this appears to be an SDK for the SOC on the module, not a simple way to connect the module to a microcontroller.

Anyone wanting to grab one of these modules can do so on Ali Express. Anyone wanting to do something with one of these modules will have a much more difficult time, most likely poking and prodding bits randomly with the help of Google translate. Should someone, or even a group of people, want to take up the task of creating a translation of the datasheet and possibly a library, we have a pretty collaborative project hosting site where you can do that. You may organize in the comments below; we’ll also be taking bets as to when a product using the ESP8266 will be found on Kickstarter. My guess is under a month.

Thanks [Liam] for the tip.

Filed under: hardware, wireless hacks

Measuring Frequency Response with an RTL-SDR Dongle and a Diode

via Hackaday» hardware

[Hans] wanted to see the frequency response of a bandpass filter but didn’t have a lot of test equipment. Using an RTL-SDR dongle, some software and a quickly made noise generator, he still managed to get a rough idea of the filter’s characteristics.

How did he do it? He ‘simply’ measured his noise generator frequency characteristics with and without the bandpass filter connected to its output and then subtracted one curve with the other. As you can see in the diagram above, the noise generator is based around a zener diode operating at the reverse breakdown voltage. DC blocking is then done with a simple capacitor.

Given that a standard RTL-SDR dongle can only sample a 2-3MHz wide spectrum gap at a time, [Hans] used rtlsdr-scanner to sweep his region of interest. In his write-up, he also did a great job at describing the limitations of such an approach: for example, the dynamic range of the ADC is only 48dB.

Filed under: hardware, wireless hacks

Building a Mesh Networked Conference Badge

via Hackaday» hardware

[Andrew] just finished his write-up describing electronic conference badges that he built for a free South African security conference (part1, part2). The end platform shown above is based on an ATMega328, a Nokia 5110 LCD, a 433MHz AM/OOK TX/RX module, a few LEDs and buttons.

The badges form a mesh network to send messages. This allows conversations between different attendees to be tracked. Final cost was the main constraint during this adventure, which is why these particular components were chosen and bought from eBay & Alibaba.

The first PCB prototypes were CNC milled. Once the PCB milling was complete there was a whole lot of soldering to be done. Luckily enough [Andrew]‘s friends joined in to solder the 77 final boards. He also did a great job at documenting the protocol he setup, which was verified using the open source tool Maltego. Click past the break to see two videos of the system in action.

Filed under: hardware, wireless hacks

Electric Imp Thermal Printer

via Hack a Day» hardware


If you’re the type of person that doesn’t mind having a pocket/purse full of crumpled receipts, then maybe you should check out this tutorial from [tombrew] on giving a thermal printer internet-connectivity.

For some of us, there’s something kind of cool about thermal printers, but it’s probably not the kind of project you’d want to burn a lot of calories on. As a developer over at Electric Imp, [tombrew] agrees with this statement, but since the Electric Imp contains both a WiFi module and processor built in, it makes it pretty easy to get your thermal printer printing off the daily weather, stock prices, news headlines, etc… In fact, the claim here is that you could have this project completed before you even finish your morning coffee… knock on wood!

From a hardware standpoint, the project is pretty straight forward; an Electric Imp with breakout board, thermal printer, and a power supply are pretty much all that’s needed. Local communication between the Electric Imp and the thermal printer is accomplished through a simple serial interface. With the roll-out of the new Electric Imp IDE a few months back, we were introduced to ‘Agents’. This is kind of a neat concept, and this tutorial breaks everything down, but basically the agent is server-side code that runs in the ‘ImpCloud’, thus giving your Electric Imp more power and capabilities to deal with complex APIs. Also, handling images (like something you want to print) can take up a ton of memory, so for this project, the agent is used to send down slices of the image you want to print one at a time. This project is just the beginning of what [tombrew] has planned, so we can’t wait to see more insanely detailed tutorials.

Filed under: hardware, wireless hacks

A Low-Cost Modular High Altitude Balloon Tracker with Mesh Networked Sensors

via Hack a Day» hardware

[Ethan] just tipped us about a project he and a few colleagues worked on last year for their senior design project. It’s a low-cost open hardware/software high altitude balloon tracker with sensors that form a mesh network with a master node. The latter (shown above) includes an ATmega644, an onboard GPS module (NEO-6M), a micro SD card slot, a 300mW APRS (144.39MHz) transmitter and finally headers to plug an XBee radio. This platform is therefore in charge of getting wireless data from the slave platforms, storing it in the uSD card while transmitting the balloon position via APRS along with other data. It’s interesting to note that to keep the design low-cost, they chose a relatively cheap analog radio module ($~40) and hacked together AFSK modulation of their output signal with hardware PWM outputs and a sine-wave lookup table.

The slave nodes are composed of ‘slave motherboards’ on which can be plugged several daughter-boards: geiger counters, atmospheric sensors, camera control/accelerometer boards. If you want to build your own system, be sure to check out this page which includes all the necessary instructions and resources.

Filed under: gps hacks, hardware, wireless hacks

A Motherboard for a WiFi Enabled SD Card

via Hack a Day» hardware


Over the last few months, a few very capable hackers have had a hand in cracking open a Transcend WiFi-enable SD card that just happens to be running a small Linux system inside. The possibilities for a wireless Linux device you can lose in your pocket are immense, but so far no one has gotten any IO enabled on this neat piece of hardware. [CNLohr] just did us all a favor with his motherboard for these Transcend WiFi SD cards, allowing the small Linux systems to communicate with I2C devices.

This build is based upon [Dmitry]‘s custom kernel for the Transcend WiFiSD card. [CNLohr] did some poking around with this system and found he could use an AVR to speak to the card in its custom 4-bit protocol.

The ‘motherboard’ consists of some sort of ATMega, an AVR programming header, a power supply, and a breakout for the I2C bus. [Lohr] wired up a LED array to the I2C bus and used it to display some configuration settings for the WiFi card before connecting to the card over WiFi and issuing commands directly to the Linux system on the card. The end result was, obviously, a bunch of blinking LEDs.

While this is by far the most complex and overwrought way to blink a LED we’ve ever seen, this is a great proof of concept that makes the Transcend cards extremely interesting for a variety of hardware projects. If you want your own Transcend motherboard, [CNLohr] put all the files up for anyone who wants to etch their own board.

Filed under: hardware, linux hacks, wireless hacks

Sending data over Bluetooth Low Energy with a cheap nRF24L01+ module

via Hack a Day» hardware

nRF24L01+ modules like the one shown above are a great way to send data wirelessly between your projects. They can be found on many websites for less than $1.50

a piece and many libraries exist for them. After having thoroughly looked at the Bluetooth Low Energy (BLE) specifications, [Dimitry] managed to find a way to broadcast BLE data with an nRF24L01+.

Luckily enough, BLE and nRF24L01+ data packets have the same preambles. However, the latter can’t send more than 32bytes in a packet and can’t hop between frequencies as fast as the BLE specification wants. [Dimitry] found the solution when he discovered that he could send unsolicited advertisements on three specific channels. In the end, considering the 32 bytes the nRF24L01+ can send, you’ll need to use 3 bytes for the CRC, 2 for the packet header, 6 for the MAC address and 5 for devices attributes. This leaves us with 16 bytes of pure data or 14 bytes to split between data and name if you want your project to have one.

Filed under: hardware, wireless hacks

TI’s CC3000 WiFi chip gets a library

via Hack a Day» hardware

About six months ago, Texas Instruments released a simple, cheap, single-chip WiFi module. At $10 a piece in quantities of 1000, the CC3000 is a much better solution to the problem of an ‘Internet of Things’ than a $50 Arduino Ethernet modules, or even the $30 Electric Imp. All indications, especially the frequent out of stock status for the dev board on TI’s web site, show the CC3000 will be a popular chip, but until now we haven’t seen a CC3000 library for the Arduino or other microcontrollers.

[Chris] just solved that problem for us with a CC3000 WiFi library for the Arduino. He ported TI’s MSP430 CC3000 library to the Arduino, allowing even the bare-bones Arduino Uno to connect to a WiFi network with just a handful of parts. The code itself takes about 12k of Flash and 350 bytes of RAM, giving anyone using the CC3000 enough room left over to do some really interesting stuff. There’s even a slimmed down library that uses somewhere between 2k and 6k of Flash, making an ATtiny-powered web server a reality.

There are a few caveats in using the CC3000 with an Arduino; it’s a 3.3 Volt part, so you’ll need a level shifter or some resistors. Also, the chip draws about 250 mA when it’s being used, so you’ll need a beefy battery if you want your project to last an entire day of use.

Now that the library is out of the way, be on the lookout for a CC3000 breakout board. Here’s one, but expect some more on the market soon.

Filed under: hardware, wireless hacks

Upgrading a router with impeccable soldering skills

via Hack a Day» hardware


[Necromant] recently acquired a router that was nearly free. Looking his gift horse in the mouth, he hooked up a serial port to see if it could run some updated firmware such as OpenWRT. The initial findings were promising; it used the same CPU as the very popular WR703N, but this free router only had 2 MiB of Flash and 8 MiB of RAM – barely enough to do anything. His solution to this problem is in the true hacker tradition: just solder some more chips onto the router.

Upgrading the RAM was comparatively easy; [Necromant] found an old stick of RAM, desoldered one of the chips, and replaced the measly 8 MiB chip with a new 64 Megabyte chip.

The Flash, though, proved more difficult. Without the right code in the Flash for the radio test, the router wouldn’t be useful at all. The solution was to read the original 2 MiB chip, read the Flash from a  WR703, and combined the two with a simple dd command. This was written to a new SPI flash chip with a buspirate and a home etched board.

Filed under: hardware, wireless hacks

A breakout board for a tiny WiFi chip

via Hack a Day» hardware


A few weeks ago, we caught wind of a very tiny, very inexpensive WiFi chip  TI is producing. Everything required of an Internet connection – TCP/IP stack, configuration utilities, and your WEP, WPA, and WPA2 security tools is included in a single tiny chip, making this a very cool device for an Internet-connected microcontroller project. There’s only one problem: TI put this chip in a really, really weird package, and there aren’t any breakout boards for it.

That is, until now. [Vince] was convinced to spend some time in Altium to design a breakout board for this tiny WiFi chip. Now, if you can get your hands on a sample of the CC3000 from TI, you can breadboard out a circuit with the help of [Vince]‘s design.

Included in [Vince]‘s git are the board files for this breakout board, schematics, and the necessary parts if anyone has the inclination to make an Eagle library. If anyone wants to spin a few of these boards and put them up on a Tindie Fundraiser, that’d be fine by us, and [Vince] would probably appreciate that as well.

Filed under: hardware, wireless hacks