Minimalist Microcontroller: Building a Bare-Bones Dev Board - In a thrilling DIY endeavour, I attempted to build the most minimalist ESP32 dev board possible. Diving deep into the schematic of the ESP32 S3 WROOM module, I chopped out the non-essentials and whittled our needs down to bare bones. The experiment saw me juggling USB data lines and voltage regulators, waving goodbye to an array of capacitors and connectors and boldly embracing the simplicity of direct connections. Despite a few hitches, the miniature Frankenboard came alive, proving that sometimes less is more...at least in the world of microcontrollers.

ESP32 Audio Input - MAX4466, MAX9814, SPH0645LM4H, INMP441 - In this blog post, I've delved deep into the world of audio input for ESP32, exploring all the different options for getting analogue audio data into the device. After discussing the use of the built-in Analogue to Digital Converts (ADCs), I2S to read ADCs with DMA, and using I2S to read directly from compatible peripherals, I go on to present hands-on experiments with four different microphones (MAX4466, MAX9814, SPH0645, INPM441). This comprehensive look at getting audio into the ESP32 should be a valuable resource for anyone hungry for a deep-dive into ESP32's audio capabilities, complete with YouTube videos for an even more detailed look!

The PCBs are in production - what have I messed up? - After some stress and trepidation, I finally took the plunge and sent my PCB design off for manufacturing. My design centers around building a large seven-segment clock with LED filaments. Jumping hurdles such as voltages, pin usage, and limiting the load on my power supply, I've settled on the ESP32 as the system's heart and come up with a final circuit design. While doing this, I've quickly realized I could improve my layout and fixed a small mistake. Also, I've prepared for either types of LED filaments - the high-voltage ones or the larger, 3v ones. However, I did bungle up a couple of things on the enable line of the shift registers and board layout. But hey, this is a learning curve, right? Can't wait to get the boards and see what other exciting errors surface!

A Potentially Explosive Error - Just received the new PCBs for the ESP32-TV project and they're looking sharp with only a tiny resistor tweak needed. But I discovered a sneaky, undocumented resistor causing a conflict between the ESP32 and USB2244 over the USB connection. Fixed that, but there's a bigger issue lurking in the design - check the schematic in the video and see if you can spot it before I reveal the explosive mistake!

E32-S3 no DAC - No Problem! We'll Use PDM - In this post, I tackle the lack of a DAC on the ESP32-S3 by demonstrating how to use Pulse Density Modulated (PDM) audio with Sigma Delta Modulation to achieve analog audio output. I explore the simplicity of creating a PDM signal and its reconstruction into an audio signal using a low pass filter, even an RC filter, though a more sophisticated active filter is recommended. I guide through using both a timer and the I2S peripheral on the ESP32 for outputting PDM data, noting the quirks and solutions for each method. And I wrap up with how straight PDM signals can drive headphones or work with various amplifiers, including the MAX98358 or SSM2537, exhibiting the versatility of PDM in audio applications with the ESP32-S3.

ESP32-S3 - Which Pins Are Safe To Use? - In this video, I've decided to dive deep into the ESP32-S3, a module ruling my lab recently due to its plug-in-and-play functionality, and the flexibility offered by its GPIO matrix. However, working with it requires vigilance, especially with regard to the strapping pins and USB data pins, among others. Discovering such quirks, I've encountered unexpected values, short glitches and the occasional code crash. To help you avoid these bumps, I've documented everything I've learned on my GitHub repo, where I'm inviting you, my fellow makers and engineers, to contribute your valuable experiences and findings. After a minor hiccup with my ESP32-TV, expect an updated PCB design, courtesy of PCBWay. Explore the ESP32-S3 with me, and let's unravel its secrets together, one pull request at a time.

Minimalist Microcontroller: Building a Bare-Bones Dev Board - Dive into the fascinating process of building a minimal ESP32-based dev board, beginning with the ESP32-S3 Wroom module, and eliminating unnecessary components. Through soldering, wire connecting, and voltage testing, we reach a product that's compact, efficient and fully functional.

Arduino Nano ESP32 - It's nice - But probably not for me. - In this video, I took a deep dive into the Arduino Nano ESP32 and compared it with other available boards in the market. Despite its seemingly high cost as compared to the options on AliExpress, its overall quality, fantastic documentation, and the fact that it fits neatly into the Arduino ecosystem makes it a good buy, especially if you've already invested in the Arduino Nano and its shields. The board has a few interesting peculiarity, including the use of a NORA-W106 module, a switch mode step-down converter for power, and an RGB LED. However, I was disappointed to find out it doesn't come with built-in battery charging. The pin labelling and remapping could definitely cause some confusion, especially if you're transitioning from other ESP32 boards. It's a fairly decent ESP32-S3 board if that's what you're after. But given a choice, I'm keener on the Unexpected Maker boards or the cheap boards on AliExpress.

Live GPIO Viewer - In my latest discovery, I found an incredibly efficient visualization tool from the last outpost workshop that upgrades how I check the status of the GPIO pins on my ESP32. It's super simple to use and allows me to monitor pin activities directly. I set up a couple of LEDs and a button on various GPIO pins to demonstrate its effectiveness and the results were fantastic. Although it currently supports only digital input and output and PWM, I'm optimistic it will expand with time. Thanks to the open-source community, you can find the setup instructions in a GitHub repo. This tool is a revelation and I highly recommend it.

Revamped Audio PCB Walkthrough: Fixing Mistakes & Enhancing Functionality - Learn how to modify a custom PCB for an ESP32 walkie-talkie project, including exposing spare GPIO pins, freeing up the DAC pin, saving GPIO pins for the microphone and amplifier, and wiring up the shutdown pin on the amplifier for low power mode.