Meetup report: 17 May 2018

TL;DR: 3D printers, robots and Sonoffs.

My Sonoff Basic Wifi switches arrived! My evening was spent getting them working and set up the way I wanted.

First step was to connect them and get them going with the stock firmware. I downloaded the EWeLink app and got one of them working.

That done, they needed to be reflashed with OS firmware.

Tasmota looked like the most complete firmware for the Sonoffs. It also had one BIG advantage: OTA (Over The Air) updating from the stock firmware to Tasmota! No need to open up and solder extra pins to the devices.

I used the experimental OTA update method and it worked perfectly. Luckily the factory firmware was still a slightly older version. The newest versions don’t work with this method.

Spoiler alert: Over the weekend I got Home Assistant running on my Raspberry Pi to integrate these switches as a home automation solution.

I let the 3D printer run in the background on a print job or 2, just to visually test the bed movement. As I suspected, right at the top of the travel, the bed moves sideways as the print head moves. This sloppyness is probably a combination of the Z-axis standing on a non-stuck-down base and the fact that the spectra line is not aligned correctly, which shows up particularly at the top of its travel. Some manual tweaking should fix this.

I let the pendulum wave run for a while and took some better photos of the waveforms.

Waveforms

Otto also worked on his printer. The print surface was not flat and calibrated, so with some effort he got the bed leveling to work.

Jan had some good inputs to add on all our projects, and helped Steph with his Alphabot. Looks like the screen is a 2-color OLED, and works as advertised, mostly.

An interesting evening, will do again.