Life, The Universe and ... Everything!

Up till now I have been using 12V and 5V power supply units on my desk to power various stuff I am tinkering with, from data loggers to sensors and so on. As I didn't like the open power terminal connectors, I 3D-printed an enclosure for them. I also took the opportunity to make multiple output terminals, so I can easily connect multiple devices simultaneously. Each output terminal has its own switch and LED and also a fuse. This is fine and good for working with stuff that works. But I've b...

I attached a Raspberry Pi Zero W running CNCJS software to my 3018 "Woodpecker" CNC machine. CNCJS is a web-based gcode feeder than can be used to control the CNC hardware. Being web-based, I can now control the CNC wirelessly from anywhere on my home network, using my desktop pc, tablet or phone. Here are my build notes. Setting Up The Raspberry Pi Zero W I started by installing the 2018-06-27 version of Raspbian Stretch Lite onto a MicroSD card using Etcher. Next, I powered up the Pi Ze...

I was quite glad when it was announce that Cytron was the non-industrial-use local distributor for the Raspberry Pi series ... and they carried the PI Zero and Pi Zero W. These are the low cost models announced at USD5/MYR20 (Pi Zero) and USD10/MYR40 (Pi Zero W -- W stands for WiFi-capable) respectively. With the dip in the Malaysian Ringgit's value recently, they are even cheaper here than in t=the US and UK. Due to production shortages, however, their sales were limited to one per custome...

My 737 I/O Controller PCB has arrived!Well to be honest, this is not the first time it has "arrived". But this is the first time that a version of the PCB has arrived which is usable, due to some earlier bugs! 8-) As i noted in my earlier post, here are the specifications: 192 digital switch inputs (expandable to 256) 128 constant current LED outputs, up to 60 mA per channel (expandable to 224)48 digits of 7-segment numeric displays8 characters of 14-segment alphanumeric displays16 servo out...

Testing out this 12V->5V DC/DC converter from Banggood. It's useful useful for 12V deployments with of a Raspberry Pi (which needs 5VDC). It also terminates with a microUSB plug, which goes directly into the Pi -- no need for any hacks. I measured the Pi 3 using roughly 90mA @ 12V on idle, and around 320mA @ 12V with all four core fully loaded, display, andUSB keyboard/touchpad connected. No low-voltage indicator appearing on the Pi's display during peak loads. I didn't notice any heat on t...

Testing a Motorized Throttle Lever for my Flight Simulator. When the auto-throttle is engaged, aircraft's systems are supposed to control the engine throttles automatically, which includes moving the actual levers. I've used a 12V 28BYJ48 Stepper Motor (modified for bipolar format for more torque) and a A4988 Bipolar Stepper Driver, together with a potentiometer to sense the Throttle position. Right now I'm still testing it standalone, with a Raspberry Pi generating pulses every 30 millise...

Up till now, I've been using the ExtPlane plugin to integrate my 737 home cockpit components with the X-Plane Flight Simulator. ExtPlane is a third party plugin that gives networked devices access to X-Plane's DataRefs and Commands. With it, external devices can query the current state of the Flight Simulator, such as the current airspeed and elevation, or the present position of a switch. It can also be used to manipulate state within the Flight Simulator, such as to change the state of a p...

SDL is a library for writing cross-platform programs that make use of graphics and other multimedia elements. While, working on an SDL2-based program, I updated the Raspberry Pi to used SDL 2.0.5. The one that came with the Pi seems to want to run under X11, whereas I wanted my app to run directly from the console. Also, SDL 2.0.5 uses hardware-accelerated OpenGL ES2 rendering for the frame buffer. You probably won't need this if using Raspbian Stretch as it already bundles SDL 2.0.5. I b...

Short Shorter Story A few weeks back I discovered that the stepper motors on my 3D printer were warm to the touch, even when not in use. I asked on the facebook group and learned that the motors are kept powered to prevent the extruder from being accidentally moved. This doesn't work for me, as since the printer is on a different floor and operated remotely, I like to leave it powered on. But I didn't like the idea of having the motors powered. So I decided to look for a remotely controllabl...

Using my GPIO expander boards, I could now assemble a stack of eight MCP23017s which would give me 16 x 8 = 128 inputs. This may sound like a lot, but when I counted the number of stuff I would need to connect for the 737 Overhead, it was quite limiting. So I spent a few weeks researching on options to increase the number of GPIOs further. Given that my toggle switches are only used for inputs, one common solution, is to multiplex a number of GPIOs together in a Matrix configuration. This is...