Spoooky CircuitPython Circuits!

After using Python for a decade, I’ve decided to finally get better at it. I think diving into CircuitPython will be a nice scaled-down universe to learn to write concise “Pythonic” code. For hardware I’m using Adafruit’s new QT Py board and CircuitPython’s new ESP32-S2 support. And for a theme this month I want to [...]
Todbot 09 Oct 19:28

RS485 Master and Slave using Modbus

I am trying to find a simple example of using Modbus to link several Arduino Boards, simply sending digital and analogue signals from the Master to each Slave.  Modbus seems overkill but the application involves large distances outdoor lighting.  I have worked through the tutorials:

Long Distance Wired Serial Communication with Arduino using RS485 and CAT Cables

I have made this work but this only works for one Slave

RS-485 MODBUS Serial Communication using Arduino UNO as Slave

Circuit Digest 08 Oct 21:24

3D Printed SCARA Arm With 3D Printer Components

One of the side effects of the rise of 3D printers has been the increased availability and low cost of 3D printer components, which are use fill for range of applications. [How To Mechatronics] capitalized on this and built a SCARA robot arm using 3D-printed parts and common 3D-printer components.

The basic SCARA mechanism is a two-link arm, similar to a human arm. The end of the second joint can move through the XY-plane by rotating at the base and elbow of the mechanism. [How To Mechatronics] added Z-motion by moving the base of the first arm on four vertical linear rods with a lead screw. A combination of thrust bearings and ball bearings allow for smooth rotation of each of the joints, which are belt-driven with NEMA17 stepper motors. Each joint has a microswitch at a certain position in its rotation to give it a home position. The jaws of the gripper slide on two parallel linear rods, and are actuated with a servo. For controlling the motors, an Arduino Uno and CNC stepper shield was used.

The arm is operated from a computer with a GUI written in Processing, which sends instructions to the Arduino over serial. The GUI allows for both direct forward kinematic control of the joints, and inverse kinematic control,  which will automatically move the gripper to a specified coordinate. The GUI can also save positions, and then string them together to do complete tasks autonomously.

The base joint is a bit wobbly due to the weight of the rest of the arm, but this could be fixed by using a frame to support it at the top as well. We really like the fact that commonly available components were used, and the link in the first paragraph has detailed instructions and source files for building your own. If the remaining backlash can be solved, it could be a decent light duty CNC platform, especially with the small footprint and large travel area. This is very similar to a wooden SCARA robots we’ve seen before, except that one put the Z-axis at the gripper. We’ve also seen a few 3D printers and pen plotters that used this layout.

Measuring Turbidity of Water to Determine Water Quality using Arduino and Turbidity Sensor

When it comes to liquids, turbidity is an important term. Because it plays an important role in liquid dynamics and is also used to measure water quality. So in this tutorial, let's discuss what is turbidity, how to measure the turbidity of a liquid using Arduino. If you want to take this project further, you can also consider interfacing a pH meter with Arduino and also read the pH value of water to better assess the quality of water.

Circuit Digest 05 Oct 12:52

Arduino Programmable Open-Source Flight Controller and Mini Drone using SMT32 and MPU6050 for Drone Enthusiasts

Pictured here is an open-source flight controller and mini drone by Shao's Gadget. YMFC (Your Multicopter Flight Controller) as it is named is a mini drone by itself or a flight controller for a full-size F450 drone that can be programmed with Arduino IDE. The open-source nature and simple design control of YMFC make it apt for the people who are working on some kind of educational project and for the drone enthusiasts too.

Circuit Digest 05 Oct 10:00

Teaching an Old Lathe New Tricks With a Programmable Power Feed

Ask anybody whose spent time standing in front of a mill or lathe and they’ll tell you that some operations can get tedious. When you need to turn down a stainless rod by 1/4″ in 0.030″ increments, you get a lot of time to reflect on why you didn’t just buy the right size stock as you crank the wheel back and forth. That’s where the lead screw comes in — most lathes have a gear-driven lead screw that can be used to actuate the z-axis ( the one which travels parallel to the axis of rotation). It’s no CNC, but this type of gearing makes life easier and it’s been around for a long time.

[Tony Goacher] took this idea a few steps further when he created the Leadscrew Buddy. He coupled a beautiful 1949 Myford lathe with an Arduino, a stepper motor, and a handful of buttons to add some really useful capabilities to the antique machine. By decoupling the lead screw from the lathe’s gearbox and actuating it via a stepper motor, he achieved a much more granular variable feed speed.

If that’s not enough, [Tony] used a rotary encoder to display the cutting tool’s position on a home-built Digital Readout (DRO). The pièce de résistance is a “goto” command. Once [Tony] sets a home position, he can command the z-axis to travel to a set point at a given speed. Not only does this make turning easier, but it makes the process more repeatable and yields a smoother finish on the part.

These features may not seem so alien to those used to working with modern CNC lathes, but to the vast majority of us garage machinists, [Tony]’s implementation is an exciting look at how we can step up our turning game. It also fits nicely within the spectrum of lathe projects we’ve seen here at Hackaday- from the ultra low-tech to the ludicrously-precise.

Prevent annoying Mac ._ files on CIRCUITPY

Example: Unzip & Download files to CIRCUITPY The entire process in a single session, using a neopixel example: Background On the Mac, the OS stores a bunch of different meta information about files inside those files. These are called “Extended Attributes” or “xattrs”. If you copy a file on a Mac to a thumbdrive or [...]
Todbot 04 Oct 06:48
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A Digital Magic 8-Ball? Signs Point to Yes

[FacelessTech] was recently charmed by one of our prized possessions as a kid — the Magic 8-Ball — and decided to have a go at making a digital version. Though there is no icosahedron or mysterious fluid inside, the end result is still without a doubt quite cool, especially for a project made on a whim with parts on hand.

It’s not just an 8-ball, it also functions as a 6-sided die and a direct decider of yes/no questions. Underneath that Nokia 5110 screen there’s an Arduino Pro Mini and a 3-axis gyro. Almost everything is done through the gyro, including setting the screen contrast when the eight ball is first powered on. As much we as love that aspect, we really like that [FacelessTech] included a GX-12 connector for easy FTDI programming. It’s a tidy, completely open-source build, and there’s even a PCB. What’s not to like? Be sure to check out the video after the break to see it in action.

Believe it or not, this isn’t the smallest Magic 8-Ball build we’ve seen. Have you met the business card version?

[via adafruit]

Eurorack diversion: PT2399 Karaoke delay module hack

I’ve not been working on my Touring Machine Eurorack modular synth module, but I have been hacking a bit in that space. Back in 2019 John Park and I saw the Waveform Magazine DIY PT2399 delay module article. I got the parts and half-assembled mine, but the build guide was pretty vague in some areas [...]
Todbot 02 Oct 21:04

Reel in the Years with a Cassette Player Synth

Variable-speed playback cassette players were already the cool kids on the block. How else are you going to have any fun with magnetic tape without ripping out the tape head and running it manually over those silky brown strips? Sure, you can change the playback speed on most players as long as you can get to the trim pot. But true variable-speed players make better synths, because it’s so much easier to change the speed. You can make music from anything you can record on tape, including monotony.

[schollz] made a tape synth with not much more than a variable-speed playback cassette player, an Arduino, a DAC, and a couple of wires to hook it all up. Here’s how it works: [schollz] records a long, single note on a tape, then uses that recording to play different notes by altering the playback speed with voltages from a MIDI synth.

To go from synth to synth, [schollz] stood up a server that translates MIDI voltages to serial and sends them to the Arduino. Then the DAC converts them to analog signals for the tape player. All the code is available on the project site, and [schollz] will even show you where to add Vin and and a line in to the tape player. Check out the demo after the break.

There’s more than one way to hack a cassette player. You can also force them to play full-motion, color video.

Via adafruit