Finishing this project was a huge relief, to say the least. It is truly my first project in which I designed everything from the ground up instead of just building up schematics from the internet. Thus, it was also my longest running project yet, and the amount of work that has gone into it just …
STM32 MIDI Controller Part 8: Conclusion and what’s next (potentially) Read More »
Finally, we are at the end of this series, where I am going to give an overview of the software behind all the menu system and of course, all the handling of user inputs and sending of MIDI messages. We’ve spent so much time configuring the various peripherals and writing driver code to abstract away …
Yes, this MIDI controller has a 4×4 grid that you have undoubtedly seen way too many times. No, it doesn’t have RGB Will it actually get used? Probably not. But hey, its a great opportunity to learn some electronics! And implementing key matrices is not as trivial as you might think. Schematic First off, if …
I really like rotary encoders as user input devices, they’re free of analog noise shenanigans, have no fixed positions, can be augmented with velocity control… Just a really nice way for the user to navigate around in menus or adjust parameters. That said, they do take up at least one extra pin per encoder compared …
STM32 MIDI Controller Part 5: Multiplexed Rotary Encoders Read More »
While PWM certainly is a mighty fine option to add dimming control to LEDs in your projects, there may be certain cases where it simply isn’t the best option. Maybe you don’t have enough PWM capable IO pins on your microcontroller? Or maybe manually bit-banging PWM control takes up too much CPU time? And you …
STM32 MIDI Controller Part 4: Bit Angle Modulation LED Dimming Read More »
Staying on the topic of ways to use the I2C peripheral of the STM32F103 microcontroller, today, I’m going to discuss how I implemented a basic bi-color LED matrix based on the MCP23017 I2C I/O expander. This is not a full blown, colorful RGB LED matrix – its literally “monochrome”, but with the massive RAM of …
STM32 MIDI Controller Part 3: DMA Driven I2C LED Matrix Read More »
Early on in the conceptualization phase of this project, I wanted something that had good customisability on board. That meant that I would need some sort of non-volatile memory to store all user changeable parameters, so I wouldn’t have to set everything up all over again every time I unplugged the thing. Out of all …
STM32 MIDI Controller Part 2: FIFO Buffered I2C EEPROM Read More »
The problem with the simple approach In part 1A, I presented a simple approach that did the job quite well. However, since the program has to wait for the slow I2C bus to send more than 30 bytes of data every single time the LCD is fully updated, it simply wouldn’t cut it for a …
STM32 MIDI Controller Part 1B: I2C Event Interrupt Driven MCP23017 LCD Read More »
This was one hands down the most challenging and frustrating part of the entire project, involving hours of staring at the reference manual for the STM32F103 microcontroller series trying to figure out why the I2C peripheral kept locking up. Maybe its just me, but the diagrams and explanations in the reference manual for the I2C …
STM32 MIDI Controller Part 1A: Wrestling with I2C, MCP23017, and a 16×2 LCD Read More »
Going into this project, I had a clear vision of what this MIDI controller would look like, and what functionality it was going to have. So, it made sense to start with CAD, since 3D printing big parts like this takes a huge amount of time, and I needed to wire everything up before I …