Mika Tuupola

Technology guy gone advertising.

How to Calibrate a Magnetometer?

Magnetometers are used to measure the strength of a magnetic field. They can also be used to determine orientation and to compensate gyro drift. Magnetometer provides the last three degrees of freedom in 9DOF sensors. There is one problem though, magnetometers are prone to distortion.


Wifi Geolocation With MicroPython

While evaluating M5Stack for a sidehustle project I created a proof of concept which needed to access wifi network, query an API and download an image. Wifi geolocation which displays a static Google map was a perfect fit. Here are some notes about it.


Install Latest MicroPython to M5Stack

M5Stack is an absolutely beautiful ESP32 based enclosure and development board. It has 320x240 TFT screen, three buttons, sd card slot, Grove I2C connector and can be powered with LiPo battery. But does it run Micropython?


Update Pycom WiPy Firmware From Commandline

WiPy is a pricey but good quality ESP32 development board from Pycom. I got mine from Pimoroni. Pycom does offer their own firmware updater but for my taste it has bit too much magic going on. I prefer to do things from commandline and I stay in control to see exactly what is going on. Quick Googling did not reveal anything so I decided to document my upgrade procedure.


Driving 595 Shift Registers

595 series shift registers come in many flavors. SN74HC595 is the most usual. TPIC6B595 is similar but can be used with more power hungry applications. Pin layouts are different but they all operate in the same way.


Simple Serial Communications With AVR libc

I like to use various Arduino boards for AVR development. What I do not like are the Arduino libraries. They are often just wrappers around libc functions or rewrites of functions libc already provides.


How Does Led Matrix Work?

Led matrices are fun toys. Who would not love blinkenlights? Electronics is hard. Electronics is much harder than programming. I had hard time trying to understand how do the led matrices work. What is best way to learn something? Build one yourself.