After performing this upgrade, the printer is much quieter than before. This is because of the change from x16 microstepping on the Duet with A4982 drivers, to interpolated x256 microstepping on the Duet WiFi with TMC2660 drivers. The noisiest component is now the 40mm electronics cooling fan under the bed. I shall search for a quieter 40mm 24V fan, or perhaps do a small redesign of the electronics rear panel to use a slower-running 50mm or 60mm fan instead.
Another benefit of the upgrade is that I can now use the printer in a different room – as I occasionally need to do when hosting meetings – without needing to run a communications cable to it. The gcode file upload speed over WiFi is about 800 kbytes per second, similar to the speed I was previously getting with wired Ethernet on the Duet 0.8.5.
Jesse from Bent-Tronics has posted a tutorial on how to make a DIY MIDI tester:
A quick and dirty (and cheap) MIDI tester. Sometimes you just need to know if a MIDI controller is outputting anything. Even many high-end MIDI modules/boxes will have a “MIDI Activity” light, just to let you know something is being transmitted/received. That’s what I have made in this video.
Using a sacrificial MIDI cable, an LED, and a 220 Ohm resistor, you too can make this tester/activity light, probably in less than 10 minutes.
The WA2EBY amplifier is a famous linear amplifier project published in QST in March and April 1999 by Mike Kossor WA2EBY. As this amplifier can give up to 50W out with 1W drive, it is a perfect pair for my Softrock RXTX amplifier.
The articles can be found on the ARRL-site (search for WA2EBY) and are highly recommended reading.
I have had a suitable box laying around for quite some time that was perfect for the amplifier project. I decided to go for Manhattan style construction using mainly the parts I already had in my junk-box and not order the PCBs and toroid set which are available from different sources on Ebay. In other words: a low-cost project.
Powerpole voltage and current monitoring is quite nice to have. One can buy commercial meters, but due to the availability of nice and cheap modules, it is very easy to make them oneself.
To the right you’ll see my combined voltage and current meter as well as my volt-meter on top of the power supply.
My homemade plunge EDM (electric discharge machining) machine built based on the book “Build an EDM” by Robert Langolois. The book consists of a series of articles that originally appeared in The Home Shop Machinist.
I deviated from the book in a couple of ways. First I sourced some of the components from scrap electronics and an electric clothes dryer that I picked up for free on the side of the road. The main transformer came from a microwave oven along with a cooling fan. A smaller transformer was sourced from an old stereo. The heating coil that I used as a power resistor was also taken from the old electric clothes dryer.
The “remote controlled beer crate” is actually just a flat plywood platform on which standard sized beer crates can be placed. It is driven and steered by two windscreen wiper motors with direct attached casters. Two swivel casters in front stabilize the construction.
On its back, you can see the power switch on the left side and the digital voltmeter (for monitoring the charge of the battery) on the right side.
All the electronics are mounted below the platform: On the top leftt, you can see the 2-channel RC receiver board, which came from a cheap toy car. As the receiver can only drive small motors, it controls the big windscreen wiper motors via relais H-bridges. On the bottom of the picture is the LI-PO battery pack, which came from my neighbor’s broken RC helicopter.
A pickup winding machine it is used to wind a guitar pickup.
You can find my previous ATmega manual pickup winding machine here
This project is a manual / CNC pickup winding machine, built on top of an ATmega8 microcontroller.
For second revision of Tannin controller, I decided to use PCBs crafted specifically for Tannin 2, instead of using OpenDeck reference board. This proved to be a very challenging task, as I literally had to do everything from scratch. The main premise behind designing electronics for this one was that I was going to use ATmega32u4 as microcontroller. In the past, I used either Arduino Nano or Arduino Pro Mini. Both of those boards are fine on their own, however, the biggest drawback to using them is that they have no native USB capabilities. In practice, this meant that I had to use serial-to-usb adapter to program them and couple more layers of software to make them talk MIDI. In my commercial designs I also used those boards, but in addition to main board I used USB MIDI board which translated serial signals from Arduino to USB MIDI.
Quite a few things inspired me to make this motor: I’ve been watching Walter Lewin’s excellent 8.02 lectures from his MIT course on electromagnetism, I saw a 3D printed motor on Hackaday, and I’m working on some simple educational science projects for kids.
I started off by copying the 3D printed motor, but made it parametric in Fusion360 so I could fiddle around with things. Thanks to Angel for helping with the 3D printing.
A few years ago I had an encounter with a ladder volume attenuator. I loved hearing the relays clicking away as they dialed-in the desired attenuation.
Ever since then I wanted to design and build one for myself. The years passed, with other more urgent projects taking priority, but I always had this thing stuck in the back of my mind. I was doing my research at a very slow rate. Slow, but steady. I came across a number of ready-made ladder attenuators, such as the RelaiXed2, the one from AMB, Vicol, and others. I also came across some uC source code, but nothing ready-made for an Arduino.