Capacitative soil moisture sensors based on this DFRobot-design (and its successors) can be found in numerous blog articles about irrigation automation. For me, they do not work out for two reasons: a) A notable temperature dependency of the measurements, and b) a high failure rate after a few months to a few years. I decided to adopt the concept of my Simple Capacitive Water Sensor for a Water Container for soil moisture measurement, which turns out to work well.
The Diamex/Tremex All-AVR programmer for ATmel microcontrollers comes as “naked” populated PCB, no case, no protection against shorts or other damage. I created a case for it, with the following design criteria:
- Protection against accidental shorts as good as possible.
- Easy access to the jumpers that control the various operation modes.
- “Park position” for the jumper that de/activates the external power (since it is often in “off” position and can easily be lost).
- LED signals need to be visible.
- Uses the existing mounting holes.
I replaced the stock hotend of the Fabtotum Personal Fabricator Hybrid Head v1 by an E3D Lite6 hotend (The full metal V6 should work the same way). In this post I describe the steps to remove the old hotend, get in the new hotend and the simple modifications to the firmware that were required.
I built a treasure chest which opens if a riddle is solved. To prove that the riddle is solved, the players need to put the correct three RFID/NFC tokens (out of several tokens to choose from) onto three RFID readers in the correct order. If they fail too often, a curse is uttered! In this post I describe the hardware selection, the electronics, the assembly and the software.
For a small project I used the ATmega328P MCU – and then the small project somewhat exploded and I needed more and more I/O-Pins. Suddenly all but the PB6 and PB7 pins were in use, and I needed exactly two more…
To create a lamp with adjustable color temperature and brightness, I use a warm/cold white dual LED strip, an ATtiny45 MCU with N-channel MOSFETs and two adjustable resistors. This article contains the hardware and software setup. The title image of this blog shows the project.