The SAM 15x15 is an Arduino development board of 28x28mm, with the same powerful controller as the Arduino Zero: the SAMD21G18. Despite the small size, it has more I/O pins than the Arduino Zero or SAMD21 Mini/Dev Breakout: 34 instead of 21. Due to the very small dimensions it will fit easily into all embedded electronic projects, even in microdrones.
Spot welder controller board
I have developed the D.I.Y spot welder because I needed a special spot welder for the building of my Maxun One solar bike. It turned out that the spot welder is being built by many people worldwide. Because the electronics was not so easy to build, I have made a printed circuit board, which is for sale, together with some other parts:
To be able to modify and repair the Chinese KU63 e-bike motor controller I have redesigned it. The KU63 may also give insight into other Chinese motor controllers.
To build the dispenser, we just need a 1mL injection syringe, a wooden stirrer, a glue gun and strong yarn. Drill 1.5mm holes in the wooden stirrer for the yarn. Mount the yarn and glue everything together with a glue gun, the picture explains everything. The needle should be shortened. Do not cut it, but bend it with two pliers back and forth until it breaks.
Precisely dispense the smallest amount of solder paste
1. Maxun One Solar bike
The first practical vehicle that drives entirely by solar energy, read more ...
Spot welder features
A fine-spot welder is one of the few equipment where building yourself is cheaper than buying. There are already published a lot of DIY spot welders, this one has some unique features:
Een van de mooiste fietstochten die ik heb gemaakt is de fietsroute lang de Maas van Maastricht naar Sedan in Frankrijk. Eerst stroomt de Maas nog door het vuile industriegebied van Seraing, maar stroomopwaarts wordt het stroomgebied steeds natuurlijker.
I use the Extreme Programming (XP) / Agile software development methodology. One of its advantages is that by using understandable memberfuctions and variables, only few comments are required. The code is readable from itself. Another aspect is that classes and memberfunctions should be independent testable. We can even use Extreme Programming at the Arduino microcontroller. Because we use inline functions, no additional machine code will be generated.
Here is a c++ codefragment of my Solar cell curvetracer:
int CurveTracer::trace(bool printCurve, int _averaging, int stepTime_ms)
for(int i=0; i<=1023; i++)
The software is split down in many memberfunctions, as you can see. Altough some memberfunctions are very short, they are still written as memberfunctions. Look at the function calcPower:
void inline CurveTracer::calcPower(int mV, int mA, int &mW, int &mWpeak)
Here is the function call. It is not necessary to use comments because the code explains itself:
calcPower(mV, mA, mW, mWpeak);
Cheap precision multimeter calibration reference
I have developed a cheap multimeter calibration reference by which you can calibrate a digital multimeter yourself. Here we calibrate my favorite multimeter, the PeakTech 2010, it has a lot of features and it cost just €35.
Switches and push buttons need debouncing. It is straightforward to do this with software, using a library. The advantages of the Switch library are: