Displaying Cyrillic fonts on a 128x64 OLED display

Recently I picked up a couple inexpensive 128x64 pixel OLED displays with an I2C interface. It turns out that displaying Russian text on these displays is not difficult. But it’s non-obvious. This is a brief description of how to make it work. First, there’s a variety of these little displays and they’re all seemingly configured a little differently. I used this device for this test.

Reading data from Si7021 temperature and humidity sensor using Raspberry Pi

The Si7021is an excellent little device for measuring temperature and humidity, communicating with the host controller over the I2C bus. This is a quick tutorial on using the Raspberry Pi to talk to this device. If you are unfamiliar with the conceptual framework of I2C or how to enable I2C access on the Raspberry Pi, I suggest starting here. Otherwise, let’s jump in. You are probably working with the device mounted on a breakout board.

Using the Raspberry Pi to communicate over the I2C bus using C

I recently wrote about using the excellent bcm2835 library to communicate with peripheral devices over the SPI bus using C. In this post, I’ll talk about using the same library to communicate over the I2C bus. Nothing particularly fancy, but you’ll need to pay careful attention to the datasheet of the device we’re using. TheTSL2561 is a sophisticated little light sensor that has a very high dynamic range and is available on a breakout board from Adafruit.

Implementing ADC using Raspberry Pi and MCP3008

Several years ago I wrote about adding analog-to-digital capabilities to the Raspberry Pi. At that time, I used an ATtinyx61 series MCU to provide ADC capabilities, communicating with the RPi via an I2C interface. In retrospect it was much more complicated than necessary. What follows is an attempt to re-do that project using an MCP3008, a 10 bit ADC that communicates on the SPI bus. MCP3008 device The MCP3008 is an 8-channel 10-bit ADC with an SPI interface1.

Peering into Anki using R

Yet another diversion to keep me from focusing on actually using Anki to learn Russian. I stumbled on the R programming language, a language that focuses on statistical analysis. Here’s a couple snippets that begin to scratch the surface of what’s possible. Important caveat: I’m an R novice at best. There are probably much better ways of doing some of this… Counting notes with a particular model type Here we’ll use R to do what we did previously with Python.

Anki database adventures: Counting notes by model type

Continuing my series on accessing the Anki database outside of the Anki application environment, here’s a piece on accessing the note type model. You may wish to start here with the first article on accessing the Anki database. This is geared toward mac OS. (If you’re not on mac OS, then start here instead.) The note type model Since notes contain flexible fields in Anki, the model for a note type is in JSON.

Accessing the Anki database with Python: Working with a specific deck

I previously wrote about accessing the Anki database using Python on mac OS. Extending that post, I’ll show how to work with a specific deck in this short post. To use a named deck you’ll need its deck ID. Fortunately there’s a built-in method for finding a deck ID by name: col = Collection(COLLECTION_PATH) dID = col.decks.id(DECK_NAME) Now in queries against the cards and notes tables we can apply the deck ID to restrict them to a certain deck.

Working with the Anki database on mac OS using Python

Not long ago I ran across this post detailing a method for opening and inspecting the Anki database using Python outside the Anki application environment. However, the approach requires linking to the Anki code base which is inaccessible on mac OS since the Python code is packaged into a Mac app on this platform. The solution I’ve found is inelegant; but just involves downloading the Anki code base to a location on your file system where you can link to it in your code.