I wrote a short page about the snow flake project from end of 2017. On the page you will find a summary of the project and the link to the repository with all the required files. Everything is open source, including the design files for the hardware and a base version of the firmware for […]
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This is the second part of the meta-tutorial, where I talk about designing a cheap plant watering sensor. If you did not already read the first part, please do it now. It contains a lot information about constraints and decisions made which lead to this point.
The first part ended with step 11, building a working prototype with the selected key components. So let us start with the next steps in this journey.
Step 12: Analyse and Measure the Prototype
Never forget why you actually built a prototype. It is your tool to verify all assumptions you made in the design phase. To do this you need the right measuring instruments.
The Power Usage
I start measuring the current of the circuit. This will show if my assumptions about the battery life will be true. For this test I use a multimeter which has a good resolution measuring in the µA range. The multimeter I use is the Testo 760-3 which is not a very well known brand. Multimeters are usually really poor at measuring low currents on low voltages, so let us see if this will work.
I also use a Fluke 114, but this one has no current measurement. It is sometimes very handy to have two multimeters, one to measure the voltage and a second one to measure the current.
For the first test I program the MCU to do all the tests in a loop and connect the power directly to the second part of the circuit. Now the power is always on and I can measure the current used by the MCU while doing the measurement.
Just running, doing the measurement of the oscillator, the second part of the circuit uses at maximum ~1.2mA. This measurement phase should be as short as possible. Later we will analyse the timing. Continue Reading
I just finished a small series of the PissOff project. After all work done, I probably would use a stencil and solder paste next time. For this series I used a slightly larger speaker to improve the loudness and sound quality. Tried some different ones, but the really good ones do not fit on the […]
I just published the guide for the five light spheres project. It is the perfect decoration for this Winter. The spheres always display a nice color combination and blend from one color to the next. It is a quiet and artful decoration. Continue reading on the project page
Recently I had the problem some expensive components did overheat in my server rack. The ventilation was not optimal and I had to install additional fans. Because this rack is in my office and I like a quiet working place, the ventilation had to be as quiet as possible. First I thought about buying a […]
I just finished part 2 of the project description for the Outmoded Sequencer. In this second part I describe the steps from the prototype to the final device. I copied the preface from the page after this link . Outmoded Sequencer Part 2 (Preface from the project page) Building the Outmoded Sequencer was a really […]
Hurray! I just finished the final Outmoded Sequencer device. The tuning of all frequencies was way faster than I expected, because I used a new method. Have a look at the following photo gallery before I tell you some details. You can see the device is build like a control desk, with the PCB a […]
Here a short update on the progress with the final Outmoded Sequencer project. I did the whole assembly of the final PCB and connected everything. You can see part of the soldering process in the following video: I accidentally cut a route on the bottom of the PCB, so I had to fix this with […]
Today beautiful violet PCBs for the Outmoded Sequencer project arrived. I use them to experiment with different approaches for the matrix. The PCBs are ordered from OSH Park, which is a community printed circuit board order service. They put PCBs from multiple parties on one large PCB, which makes everything cheaper.
I just started an interesting new project: The Outmoded Sequencer Project. It is an minimalistic music machine. You can use a 8×8 “programming” matrix to create simple melodies which are looping endlessly. This melody can be changed while the device is playing it. Here a short demonstration: The device is divided into several parts as […]