LEARNING NOTES
English translations are generated with an LLM and published only after human review.
The local voice platform originally called TTS again whenever the same text was sent, creating a duplicate MP3. Starting with that real duplicate-file problem, this article explains why audio assets and playback jobs should be separate, and how cache keys, history playback, resending, and legacy database migration fit together.
Read articleI moved the ESP32-S3 from playing audio embedded in firmware to speaking text entered dynamically in a browser. This article documents the working path from the web UI through local TTS and a task queue to the ESP32, MAX98357A, and speaker—and clearly marks the voice-input work that remains.
Read articleA hands-on ESP32-S3 voice playback build: adapt a two-pin speaker connector to the MAX98357A screw terminal, complete the five-wire I²S connection, and verify the audio output with three test tones and five web-generated voice clips.
Read articleTo practice soldering while ending up with something usable, I chose a YCA2109 electronic dice practice board. This article records how I started with a bare board and a bag of components, spent about five or six hours assembling, soldering, and troubleshooting it, and finally got the LEDs to light briefly.
Read articleA freshly soldered YCA2109 electronic dice had all LEDs unlit when powered; the voltage after connecting the battery holder to the circuit board was only about 2.2V, and the two chips became noticeably hot after about 10 minutes. This article documents how I worked through the power supply, button, multimeter range, and input diode step by step, eventually finding that the two DIP chips were in the wrong orientation; after flipping them, the electronic dice resumed operation and could randomly stop on different numbers.
Read articleWhen I first connected the GMT130-V1.0, I could only follow the wiring table. This article groups VCC, GND, BLK, RES, SCK, SDA, and DC into four categories, and walks along the complete display chain to explain how they turn ESP32 code into a visible image, and how to safely re-plan the wiring once you understand it.
Read articleA GMT130-V1.0 had a working backlight but never displayed a single pixel, even though the driver chip and resolution were correct. This article retraces how I moved from a black screen on software SPI Mode 0 to hardware SPI that actually applies SPI_MODE3, then verified the fix with a five-color loop and a power-cycle test.
Read articleFor my first time soldering pins onto an INMP441, I skipped the practice board and went straight to the real thing. Twenty minutes later, I had six oddly shaped solder joints. This failure taught me: tutorials and AI can teach knowledge, but hands-on skill only grows from practice.
Read articleA 1.8-inch 128×160 ST7735 can already display the main content, but fixed colored lines remain on the right and bottom. This article uses a single-variable hands-on test to show how to identify initialization parameter mismatch from image offset, and verifies whether INITR_GREENTAB fits the current panel.
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