ISM Communications for Arduino

If you want to wirelessly communicate between devices, WiFi and Bluetooth are obvious choices. But there’s also the ISM (industrial, scientific, and medical) band that you use. There are inexpensive modules like the SX1278 that can handle this for you using LoRa modulation, but they haven’t been handy to use with an Arduino. [Jan] noticed the same thing and set out to build a shield that allowed an Arduino to communicate using LoRa. You can find the design data on GitHub. [Jan] calls it the LoRenz shield.

According to [Jan], the boards cost about $20 to $30 each to make, and most of that cost was in having PC boards shipped. LoRa lets you trade data rate for bandwidth, but typical data rates are fairly modest. As for range, that depends on a lot of factors, too, but we’ve seen ranges quoted in terms of miles.

Depending on where you live, there may be legal restrictions on how you use a radio like the SX1278. You should understand your local laws before you buy into using the ISM bands. We aren’t sure it would be wise, but the board can coexist with three other similar shields. So you could get 4 radios going on one Arduino if you had too and could manage the power, RF, and other issues involved. The breakout board the module uses has an antenna connector, so depending on your local laws, you could get a good bit of range out of one of these.

[Jan] promises a post on the library that makes it all work shortly, but you can find the code on GitHub now. If you look at the code in the examples directory, it seems pretty easy. You’d have to sling some software, but the SX1278 can support other modes in addition to LoRA including FSK and other data modulation techniques.

We’ve seen other LoRa shields, but not many. If you are interested in other wireless technologies, we’ve talked about them quite a bit. If you want a basic introduction to LoRa, [Andreas Spiess’] video below is a good place to start.

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ESP to Wireshark

Everyone’s favorite packet sniffing tool, Wireshark, has been around for almost two decades now. It’s one of the most popular network analysis tools available, partially due to it being free and open source. Its popularity guaranteed that it would eventually be paired with the ESP32/8266, the rising star of the wireless hardware world, and [spacehuhn] has finally brought these two tools together to sniff WiFi packets.

The library that [spacehuhn] created uses the ESP chip to save Pcap files (the default Wireshark filetype) onto an SD card or send the data over a serial connection. The program runs once every 30 seconds, creating a new Pcap file each time. There are many example scripts for the various hardware you might be using, and since this is written for the ESP platform it’s also Arduino compatible. [spacehuhn] has written this as a proof-of-concept, so there are some rough edges still, but this looks very promising as a network analysis tool.

[spacehuhn] is no stranger to wireless networks, either. His YouTube channel is full of interesting videos of him exploring various exploits and testing other pieces of hardware. He’s also been featured here before for using an ESP8266 as a WiFi jammer.

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Stalk Your Cats With A Browser-Controlled Robot

A good robot is always welcome around here at Hackaday, and user [igorfonseca83]’browser-controlled ‘bot s is no exception. Felines beware.

[igorfonseca83] — building on another project he’s involved in — used simple materials for the robot itself, but you could use just about anything. His goal for this build was to maximize accessibility in terms of components and construction using common tools.

An Arduino Uno gets two D/C motors a-driving using an H-bridge circuit — granting independent control the wheels — an ESP8266 enabling WiFi access, with power provided by a simple 5V USB power bank. [igorfonseca83] is using an Android smartphone to transmit audio and video data; though this was mostly for convenience on his part, a Raspberry Pi and camera module combo as another great option!

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Helix Display Brings Snake Into Three Dimensions

Any time anyone finds a cool way to display in 3D — is there an uncool way? — we’re on board. Instructables user [Gelstronic]’s method involves an array of spinning props to play the game Snake in 3D.

The helix display consists of twelve props, precisely spaced and angled using 3D-printed parts, each with twelve individually addressable LEDs. Four control groups of 36 LEDs are controlled by the P8XBlade2 propeller microcontroller, and the resultant 17280 voxels per rotation are plenty to produce an identifiable image.

In order to power the LEDs, [Gelstronic] used wireless charging coils normally used for cell phones, transferring 10 W of power to the helix array.  A brushless motor keeps things spinning, while an Arduino controls speed and position via an encoder. All the links to the code used are found on the project page, but we have the video of the display in action is after the break.

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Mitosis: Anatomy of a Custom Keyboard

Ergonomic. Wireless. Low-latency. Minimalist. Efficient. How far do you go when you design your own open-source keyboard? Checking off these boxes and providing the means for others to do so, Redditor [reverse_bias] presents the Mitosis keyboard, and this thing is cool.

The custom, split– as the namesake implies — mechanical keyboard has 23 keys on each 10 cm x 10 cm half, and, naturally, a custom keymapping for optimal personal use.

Upper and lower PCBs host the keys and electronic circuits respectively, contributing to the sleek finished look. Key caps and mechanical switches were ripped from sacrificial boards: two Waveshare core51822 Bluetooth modules are used for communication, with a third module paired with a Pro Micro make up the receiver. Continue reading “Mitosis: Anatomy of a Custom Keyboard”

Networking: Pin the Tail on the Headless Raspberry Pi

Eager to get deeper into robotics after dipping my toe in the water with my BB-8 droid, I purchased a Raspberry Pi 3 Model B. The first step was to connect to it. But while it has built-in 802.11n wireless, I at first didn’t have a wireless access point, though I eventually did get one. That meant I went through different ways of finding it and connecting to it with my desktop computer. Surely there are others seeking to do the same so let’s take a look at the secret incantations used to connect a Pi to a computer directly, and indirectly.

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Robot Hand Goes Wireless

We can’t decide if [MertArduino’s] robotic hand project is more art or demonstration project. The construction using springs, fishing line, and servo motors isn’t going to give you a practical hand that could grip or manipulate anything significant. However, the project shows off a lot of interesting construction techniques and is a fun demonstration for using nRF24L01 wireless in a project. You can see a video of the contraption, below.

A glove uses homemade flex sensors to send wireless commands to the hand. Another Arduino drives an array of servo motors that make the fingers flex. You don’t get fine control, nor any real grip strength, but the hand more or less will duplicate your movements. We noticed one finger seemed poorly controlled, but we suspect that was one of the homemade flex sensors going rouge.

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