There’s no doubt that the ESP8266 has made creating little WiFi widgets pretty easy. However, a lot of projects hard code the access point details into the device. There’s a better way to do it: use the WiFiManager library. [Witnessmenow] has a good tutorial and a two-minute video (which you can see below).
Hard coding is fine if you are just tinkering around. However, if you are going to send your device away (or even take it with you somewhere) you probably don’t want to reprogram it every time you change access points. This problem is even worse if you plan on a commercial product. WiFiManager does what a lot of commercial devices do. It initially looks like an access point. You can connect to it using a phone or other WiFi device. Then you can configure it to join your network by setting the network ID, password, etc.
Continue reading “Configure ESP8266 Wifi with WiFiManager”
When [sticilface] started using the Arduino IDE to program an ESP8266, he found he was running out of RAM quickly. The culprit? Strings. That’s not surprising. Strings can be long and many strings like prompts and the like don’t ever change. There is a way to tell the compiler you’d like to store data that won’t change in program storage instead of RAM. They still eat up memory, of course, but you have a lot more program storage than you do RAM on a typical device. He posted his results on a Gist.
On the face of it, it is simple enough to define a memory allocation with the PROGMEM keyword. There’s also macros that make things easier and a host of functions for dealing with strings in program space (basically, the standard C library calls with a _P suffix).
Continue reading “Save ESP8266 RAM with PROGMEM”
One of the sticking points for us with our own Internet of Things is, ironically, the Internet part. We build hardware happily, but when it comes time to code up web frontends to drive it all, the thrill is gone and the project is only half-done.
Including some simple web-based scripting functionality along with the microcontroller basics is one of the cleverest tricks up ESP8266 BASIC’s sleeves. BASIC author [mmiscool] puts it to good use in this short demo: a complete learning IR remote control that’s driven through a web interface, written in just a few lines of BASIC.
Note that everything happens inside the ESP8266 here, from hosting the web page to interpreting and then blinking back out the IR LED codes to control the remote. This is a sophisticated “hello world”, the bare minimum to get you started. The interface could look slicker and the IR remote could increase its range with more current to the LED, but that would involve adding a transistor and some resistors, doubling the parts count.
For something like $10 in parts, though, this is a fun introduction to the ESP and BASIC. Other examples are simpler, but we think that this project has an awesome/effort ratio that’s hard to beat.
For the longest time now, I’ve wanted to build a real, proper radio telescope. To me, this means a large parabolic reflector, a feed horn made of brass sheet, coat hanger wire, and at least for the initial experiments, an RTL-SDR dongle. I’ve done the calculations, looked at old C-band antennas on Craigslist, and even designed a mount or two that would make pointing the dish possible. I’ve done enough planning to know the results wouldn’t be great. After months of work, the best I could ever hope for is a very low-resolution image of the galactic plane. If I get lucky, there might be a bright spot corresponding to Sagittarius A.
There are better ways to build a radio telescope in your back yard, but the thought of having a gigantic parabolic dish out back, peering into the heavens, has stuck with me. I’ve even designed a dish that can be taken apart easily and transported because building your own dish is far cooler than buying a West Virginia state flower from a guy on Craigslist.
Recently, I was asked to come up with a futuristic, space-ey prop for an upcoming video. My custom-built, easily transportable parabolic antenna immediately sprang to mind. The idea of a three-meter diameter parabolic dish was rejected for something a little more practical and a little less expensive, but I did go so far as to do a few more calculations, open up a CAD program, and start work on the actual design. As a test, I decided to 3D print a small model of this dish. In creating this model, I inadvertently created the perfect WiFi antenna for an ESP8266 module using nothing but 3D printed parts, a bit of epoxy, and duct tape.
Continue reading “Increase The Range Of An ESP8266 With Duct Tape”
While there are apps that will display plane locations, [squix78] wanted to build a dedicated device for plane spotting. The ESP8266 PlaneSpotter Color is a standalone device that displays a live map with plane data on a color TFT screen. This device expands on his PlaneSpotter project, adding a color display and mapping functions.
First up, the device needs to know where planes are. The ADS-B data that is transmitted from planes contains useful data including altitude, velocity, position, and an identifier unique to the aircraft. While commercial services exist for getting this data, the PlaneSpotter uses ADS-B Exchange. You can set up a Raspberry Pi to record this data, and provide it to ADS-B Exchange.
With the plane data being received from the ADS-B Exchange API, it’s time to draw to the screen. The JPEGDecoder fork for ESP8266 is used for drawing images, which are fetched from the MapQuest API as JPEGs.
Finally, geolocation is needed to determine where in the world the PlaneSpotter is. Rather than adding a GPS module, [squix78] went with a cheap solution: WiFi geolocation. This uses identifying information and signal strengths from nearby WiFi access points to determine location. This project uses a public API by [Alexander Mylnikov], which returns a JSON object with longitude and latitude.
This project demonstrates what the ESP8266 is capable of, and brings together some neat techniques. If you’re looking to geolocate or display maps on an ESP8266, the code is available on Github.
Continue reading “Tracking Planes with an ESP8266”
For simply getting your project connected to WiFi, a least among hacker circles, nothing beats the ESP8266. But it’s not the only player out there, and we love to see diversity in the parts and languages that we use. One of the big shortcomings of the ESP8266 is the slightly-oddball Xtensa CPU. It’s just not as widely supported by various toolchains as its ARM-based brethren.
And so, when [Zach] wanted to do some embedded work in Rust, the ESP8266 was out of the picture. He turned to the RTL8710, a very similar WiFi module made by Realtek. Documentation for the RTL8710 is, at the moment, crappy, much as the ESP8266 documentation was before the hacker community had at it. But in trade for this shortcoming, [Zach] got to use the LLVM compiler, which supports the ARM architecture, and that means he can code in Rust.
In the end, the setup that [Zach] describes is a mix of FreeRTOS and some of the mbed libraries, which should be more than enough to get you up and running fairly painlessly on the chip. We’ve actually ordered a couple of these modules ourselves, and were looking to get started in straight C, but having Rust examples working doesn’t hurt, and doesn’t look all that different.
Is anyone else using the RTL8710? An ARM-based, cheap WiFi chip should be interesting.
The smart thermostat has become in a way the public face of the Internet of Things. It’s a demonstration that technological uptake by the general public is driven not by how clever the technology is, but by how much use they can see in it. A fridge that offers your recipes or orders more eggs may be a very neat idea, but at street level a device allowing you to turn your heating on at home before you leave work is much cooler. Products like Nest or Hive have started to become part of normal suburban life.
There is no reason though for an IoT thermostat to be a commercial product like the two mentioned. Our subject today demonstrates this; SST is a Wi-Fi smart thermostat using an ESP8266 that can be controlled by an app, thanks to its use of the open-source Souliss IoT Framework.
The build is very well finished, with PCBs, colour display and other components in a neat 3D-printed box. It’s a project that you could put in front of an end-user, it’s finished to such a high standard. Physical entity files are available from the hackaday.io page linked above, while its firmware is available in a GitHub repository. THere is a video showing some of the device’s capabilities, which we’ve put below the break.
Continue reading “SST Is A Very Tidy ESP8266 Smart Thermostat”