Wireless MicroPython Programming With Thonny

April 29, 2021 by Chris Lott 11 Comments

I’ve been playing with a few MicroPython projects recently on several different embedded platforms, including a couple of ESP32 WiFi modules. There are various ways to program these modules:

Use a serial terminal and ampy (maintained by [devxpy] since being dropped by Adafruit in 2018).
If you use Pycom boards or WiFy firmware, there are the pymakr plugins for Atom and Visual Studio.
If you prefer the command-line like me, there is rshell by one of the top MicroPython contributors [Dave Hylands].

For over a year, I have been quite happy with rshell until I started working on these wireless nodes. Being lazy, I want to tinker with my ESP32 modules from the sofa, not drag my laptop into the kitchen or balcony to plug up a USB cable. Can’t I work with them wirelessly?

Well, you can use WebREPL. While its functional, it just didn’t strike my fancy for some reason. [Elliot] mentioned in a recent podcast that he’s using telnet to access his wireless nodes, but he’s using esp-link on an ESP8266, which means throwing another chip into the mix.

The Thonny IDE

I had all but given up when by chance I saw this video on the Dronebot Workshop channel about running MicroPython on the new Raspberry Pi Pico boards. Bill was using Thonny, a Python IDE that is popular in the education community. Thonny was introduced in 2015 by Aivar Annamaa of the University of Tartu in Estonia. Thonny was designed to address common issues observed during six years of teaching Python programming classes to beginners. If you read about the project and its development, you’ll see that he’s put a lot of effort into making Thonny, and it shows.

Leaning about Thonny got me curious, and after a little digging I discovered that it has WebREPL support for MicroPython right out-of-the-box. Although this is a new feature and classified as experimental, I found it reasonably stable to use and more than adequate for home lab use. Continue reading “Wireless MicroPython Programming With Thonny” →

The Evil Crow Is Ready To Cause Some RF Mayhem

April 27, 2021 by Tom Nardi 34 Comments

There’s no doubt that the RTL-SDR project has made radio hacking more accessible than ever, but there’s only so far you can go with a repurposed TV tuner. Obviously the biggest shortcoming is the fact that you can only listen to signals, and not transmit them. If you’re ready to reach out and touch someone, but don’t necessarily want to spend the money on something like the HackRF, the Evil Crow RF might be your ideal next step.

This Creative Commons licensed board combines two CC1101 radio transceivers and an ESP32 in one handy package. The radios give you access to frequencies between 300 and 928 MHz (with some gaps), and the fact that there are two of them means you can listen on one frequency while transmitting on another; opening up interesting possibilities for relaying signals. With the standard firmware you connect to a web interface running on the ESP32 to configure basic reception and transmission options, but there’s also a more advanced RFQuack firmware that allows you to control the hardware via Python running on the host computer.

Using the Evil Crow RF without a computer.

One particularly nice feature is the series of buttons located down the side of the Evil Crow RF. Since the device is compatible with the Arduino IDE, you can easily modify the firmware to assign various functions or actions to the buttons.

In a demonstration by lead developer [Joel Serna], the physical buttons are used to trigger a replay attack while the device is plugged into a standard USB power bank. There’s a lot of potential there for covert operation, which makes sense, as the device was designed with pentesters in mind.

As an open source project you’re free to spin up your own build of the Evil Crow RF, but those looking for a more turn-key experience can order an assembled board from AliExpress for $27 USD. This approach to hardware manufacturing seems to be getting popular among the open source crowd, with the Open-SmartWatch offering a similar option.

[Thanks to DJ Biohazard for the tip.]

An ESP32 Development Board For Sailors

April 25, 2021 by Anool Mahidharia 8 Comments

[Matti Airas] wanted to have a better electronics platform for making his boat smarter, more connected, and safer. He found traditional marine electronics expensive and not suited for hacking and tinkering. There was also the issue of lack of interoperability between device generations from the same supplier and between different brands. This led him to design the Sailor Hat with ESP32 — a marine specific, open source hardware development board.

Applications include all kinds of sensor and control interfaces for the boat, such as measurement of fuel or water level, engine RPM, anchoring chain length counter, or setting up smart lighting or smart refrigeration control. The board is designed to work with the traditional NMEA 2000 standard, as well as with Signal K. NMEA 2000 is standardized as IEC 61162-3, but isn’t open source or free. Signal K, on the other hand, is free and open source, and can co-exist alongside NMEA 2000.

The marine environment can be pretty harsh with extremes of temperature, rain, humidity, condensation and vibration. Boats, just like automobiles, have a notoriously noisy electrical environment and [Matti] has paid special attention to noise and surge suppression throughout the board. The board can work with either 12 V or 24 V bus systems since the on board DC-DC converter is rated up to 32 V input. Connections between the board and the outside world need to be very robust, so it is designed to accept various types of connectors depending on how robust you want it to be.

The Sailor Hat is based around a standard ESP32-WROOM-32 module. Interfaces include a CAN bus transceiver, opto-coupled input and output, I²C, 1-wire and QWIIC interfaces, USB Micro-B programming conector, plus a couple of buttons and LEDs. All of the ESP32 GPIO pins are terminated on a GPIO header, with jumper options to disable terminations to the standard interfaces and instead route them to the GPIO header as needed. Additionally, there’s a generous prototyping area to add additional hardware to the board. Hardware design files are hosted on the project repository on GitHub.

On the software side, there are several frameworks that can be used, with PlatformIO, SensESP, ESPHome and Visual Studio Code being the recommended choices. Or you could use any of the widely available SDK’s for the ESP32 platform — Espressif SDK, Arduino Core for ESP32, MicroPython, NodeMCU or Rust.

[Matti]’s NMEA 2000 USB gateway example is a good way to get a grip on hardware assembly and software installation required to build a practical project using the Sailor Hat. The board is designed to withstand a harsh electrical environment. But it’s mechanical installation obviously requires greater care if it has to survive marine applications. The Sailor Hat can be installed in commonly available, 100x68x50 mm or larger plastic waterproof enclosures, rated for IP65 or higher. The bulkhead connectors and cable glands also need to be appropriately rated, and the enclosure may possibly need a IP68 rated ventilation plug to take care of environmental cycling within the enclosure.

Fertilizing Plants With A Custom 3D-Printed Pump

April 25, 2021 by Bryan Cockfield 20 Comments

For all but the most experienced gardeners and botanists, taking care of the soil around one’s plants can seem like an unsolvable mystery. Not only does soil need the correct amount of nutrients for plants to thrive, but it also needs a certain amount of moisture, correct pH, proper temperature, and a whole host of other qualities. And, since you can’t manage what you can’t measure, [Jan] created a unique setup for maintaining his plants, complete with custom nutrient pumps.

While it might seem like standard plant care on the surface, [Jan]’s project uses a peristaltic pump for the nutrient solution that is completely 3D printed with the exception of the rollers and the screws that hold the assembly together. With that out of the way, it was possible to begin adding this nutrient solution to the plants. The entire setup from the pump itself to the monitoring of the plants’ soil through an array of sensors is handled by an ESP32 running with help from ESPHome.

For anyone struggling with growing plants indoors, this project could be a great first step to improving vegetable yields or even just helping along a decorative houseplant. The real gem is the 3D printed pump, though, which may have wider applications for anyone with a 3D printer and who also needs something like an automatic coffee refilling machine.

The Beat Goes On With This ESP32 Page Turner

April 16, 2021 by Tom Nardi 3 Comments

Looking for a hands-free way to page through sheet music on an iPad, [The_Larch] came up with this simple Bluetooth input device based on the ESP32. The microcontroller just needed to have two switches wired into the GPIO pins, in this case the same heavy-duty plungers you’d find on a guitar pedal, and a USB bulkhead pass-through to provide power. Thanks to the excellent ESP32-BLE-Keyboard library, it only took a few lines of code to fire off the appropriate key strokes when the left or right button was pressed.

While undeniably a simple project from an electronics standpoint, the wooden enclosure [The_Larch] built is an interesting change of pace from the 3D printed fare we normally see around these parts. It started life as strips of oak reclaimed from an old kitchen table, which were laminated together to make a solid block. A large spade bit was then used to bore into the block to make a void for the electronics, and a second flat piece of oak was fashioned into a front panel.

Creating Bluetooth input devices with the ESP32 is so incredibly straightforward that we’re honestly a little surprised we don’t see the trick used more often. Especially when you consider all of the custom made keyboards that have graced these pages over the last couple of years. The tools are available for anyone who wants them, so you have to wonder if hackers just aren’t fond of using Bluetooth for something as important as a keyboard?

Remote Controlled Car Gets Active Suspension

April 14, 2021 by Bryan Cockfield 14 Comments

Active suspensions are almost a holy grail for cars, adding so much performance gain that certain types have even been banned from Formula 1 racing. That doesn’t stop them from being used on a wide variety of luxury and performance cars, though, as they can easily be tuned on the fly for comfort or improved handling. They also can be fitted to remote controlled cars as [Indeterminate Design] shows with this electronic servo-operated active suspension system for his RC truck.

Each of the four servos used in this build is linked to the mounting point of the existing coilover suspension on the truck. This allows the servo to change the angle that the suspension is positioned while the truck is moving. As a result, the truck has a dramatic performance enhancement including a tighter turning radius, more stability, and the capability of doing donuts. The control system runs on an Arduino with an ESP32 to enable live streaming of data, and also includes an MPU6050 to monitor the position of the truck’s frame while it is in motion.

There’s a lot going on in this build especially with regard to the control system that handles all of the servos. Right now it’s only programmed to try to keep the truck’s body relatively level, but [Indeterminate Design] plans to program several additional control modes in the future. There’s a lot of considerations to make with a system like this, and even more if you want to accommodate for Rocket League-like jumps. Continue reading “Remote Controlled Car Gets Active Suspension” →

New Part Day: Espressif ESP32-C6 Includes WiFi 6 And A RISC-V Core

April 11, 2021 by Kerry Scharfglass 15 Comments

If you’re a reader of Hackaday, then you’ve almost certainly encountered an Espressif part. The twin microcontroller families ESP8266 and ESP32 burst onto the scene and immediately became the budget-friendly microcontroller option for projects of all types. We’ve seen the line expand recently with the ESP32-C3 (packing a hacker-friendly RISC-V core) and ESP32-S3 with oodles of IO and fresh new CPU peripherals. Now we have a first peek at the ESP32-C6; a brand new RISC-V based design with the hottest Wi-Fi standard on the block; Wi-Fi 6.

There’s not much to go on here besides the standard Espressif block diagram and a press release, so we’ll tease out what detail we can. From the diagram it looks like the standard set of interfaces will be on offer; they even go so far as to say “ESP32-C6 is similar to ESP32-C3” so we’ll refer you to [Jenny’s] excellent coverage of that part. In terms of other radios the ESP32-C6 continues Espressif’s trend of supporting Bluetooth 5.0. Of note is that this part includes both the coded and 2 Mbps Bluetooth PHYs, allowing for either dramatically longer range or a doubling of speed. Again, this isn’t the first ESP32 to support these features but we always appreciate when a manufacturer goes above and beyond the minimum spec.

The headline feature is, of course, Wi-Fi 6 (AKA 802.11ax). Unfortunately this is still exclusively a 2.4GHz part, so if you’re looking for 5GHz support (or 6GHz in Wi-Fi 6E) this isn’t the part for you. And while Wi-Fi 6 brings a bevy of features from significantly higher speed to better support for mesh networks, that isn’t the focus here either. Espressif have brought a set of IoT-centric features; two radio improvements with OFDMA and MU-MIMO, and the protocol feature Target Wake Time.

OFDMA and MU-MIMO are both different ways of allowing multiple connected device to communicate with an access point simultaneously. OFDMA allows devices to slice up and share channels more efficiency; allowing the AP more flexibility in allocating its constrained wireless resources. With OFDMA the access point can elect to give an entire channel to a single device, or slice it up to multiplex between more than once device simultaneously. MU-MIMO works similarly, but with entire antennas. Single User MIMO (SU-MIMO) allows an AP and connected device to communicate using a more than one antenna each. In contrast Multi User MIMO (MU-MIMO) allows APs and devices to share antenna arrays between multiple devices simultaneously, grouped directionally.

Finally there’s Target Wake Time, the simplest of the bunch. It works very similarly to the Bluetooth Low Energy (4.X and 5.X) concept of a connection interval, allowing devices to negotiate when they’re next going to communicate. This allows devices more focused on power than throughput to negotiate long intervals between which they can shut down their wireless radios (or more of the processor) to extended battery life.

These wireless features are useful on their own, but there is another potential benefit. Some fancy new wireless modes are only available on a network if every connected device supports them. A Wi-Fi 6 network with 10 Wi-Fi 6 devices and one W-Fi 5 (802.11ac) one may not be able to use all the bells and whistles, degrading the entire network to the lowest common denominator. The recent multiplication of low cost IoT devices has meant a corresponding proliferation of bargain-basement wireless radios (often Espressif parts!). Including new Wi-Fi 6 exclusive features in what’s sure to be an accessible part is a good start to alleviating problems with our already strained home networks.

When will we start seeing the ESP32-C6 in the wild? We’re still waiting to hear but we’ll let you know as soon as we can get our hands on some development hardware to try out.

Thanks to friend of the Hackaday [Fred Temperton] for spotting this while it was fresh!