Controlling multiple heatbands using PWM via an Atmel AVR
11 mins
A mini project that summarizes a simple method to control a bunch of 100W silicone heatbands used to bake a vacuum system. Control is done using a PWM controller realized inside an AVR using a pretty simple implementation, remote control of the duty cycle is offered via an ESP8266 based WiFi capable NodeMCU
Statistics on chat service online status
21 mins
Playing around with scraping online status information from a social networks chat service and doing some statistical analysis
Dynamic imports in Python
4 mins
A simple summary on how to dynamically load modules from files in Python similar to the dlopen/dldsym/dlclose semantics in C
Implementing a simple websocket server in Python
7 mins
This is a simple short summary on how one can build a websocket server for use with ones JavaScript web application in Python using asyncio and websockets package
Logarithm and exponential function with OpAmps
7 mins
A summary how to implement the logarithmic and exponential function using operational amplifiers - and how to use this to build simple mixers when combining with a simple summation amplifier
Building simple function generators using OpAmps (OpAmp based multivibrator)
19 mins
Summary on how to use operational amplifiers to build simple function generators such as square wave function generators. This approach can be used to build simple laboratory function generators as well as low frequency oscillators used for various applications.
Mini summary on how to solve linear equations in Krylov subspaces
23 mins
A write up of the methods used to iteratively solve arbitrary linear equations systems. This includes the definition of Krylov subspace solvers, the Lanczos and Arnoldi algorithm to build orthogonal subspaces, a summary of the steepest descent and projective methods and then as an real world realization of projective methods the conjugate gradient (CG) and generalized minimal residual (GMRES) method.
Solving linear least squares problems using QR decomposition
7 mins
Mini article on how one can solve the linear least squares problem numerically using QR matrix decomposition
Whats the Bayesian rule and how to apply for simple tests
10 mins
Due to still common demand this is a short summary of the Bayesian rule for single events as well as a calculator that uses estimated prevalence, sensitivity and specificity, puts these values into Bayes rule and calculates the probabilities for correct and false results.
