Size Does Matter: Why -Os Beat -O2 on My ESP32-S3 I put my ESP32-S3 dev board from PCBWay through a quick performance workout by decoding a baked-in animated GIF with Larry Bankâs decoder and tweaking ESP-IDF settings. Cranking the CPU to 240MHz gave the expected ~1.5Ă bump, -Os beat -O2, switching flash from DIO to QIO shaved a bit more, and turning the caches up to 11 pushed it further. Best combo: 240MHz, -Os, QIO, max caches (with a larger partition and watchdog off). Nice little speed win. 07 March 2026
Even more AliExpress gadgets Another shamelessly overstuffed mailbagâcheers to PCBWay for fueling the bench carnage. I poked UV sensor cards with a curing lamp (they go purple then fade), sifted through robot gears, and lit some fragile LED filament letters (~2.7 V, happy around 100 mA). A USB photocatalytic mosquito trap spins at 0.02 A (teardown later), an OV7670 cam joins the ESP32/UVC experiments, and a chunky COB strip looks like a 12 V amp-gobbler. Bonus: surprisingly decent keyring torches with âpoliceâ flash, a hilarious translation on a temp/humidity doodad, and watch oiler wands that are perfect for painting on solder resistâprojects incoming. 07 March 2026
Single Button Games for the ESP32-C3 0.42 Inch OLED Module #arduino #esp32 I turn up the heat up here. Beats throb, energy climbsâno words, just pulse, sweat, and lift. 07 March 2026
I Turned an ESP32 into a Thermal USB Webcam Last time I made an ESP32 pretend to be a webcam; this time itâs a real USB UVC cam streaming MJPEG. Then I go further: I bolt on a tiny 32x24 infrared sensor, scale it up to 320x240 with nearest-neighbor or bilinear, JPEG it, and stream it like any normal webcam. Along the way I show why ESP32-CAM wonât work (no native USB), dive into I2C gremlins (run a scanner first, check pull-ups), and fix a flaky 3.3V regulator solder job. Quick hardware tour: onboard 2.2K pull-ups, ME6212 LDO, and an AT32F415 MCU. Audio can waitâtodayâs all about making thermal... 07 March 2026
Amazon Basics vs SanDisk: I Cut Them Open I cracked open an Amazon Basics microSD-to-SD adapter (the one I fixed last video) and a branded SanDisk to see whatâs actually different inside. Under the microscope the contact geometry is surprisingly different: Amazon uses springy bent pins the card slides underâwith a clear fatigue weak point I already snappedâwhile the SanDisk has staggered-length contacts the card presses down onto, with what looks like heavier gold plating. Iâm leaning toward the SanDisk for robustness; shout out to PCBWay for the dev boards, and let me knowâA or B? 07 March 2026
My ESP32S3 Thinks It's a WebCam! I turned a vanilla ESP32-S3 dev board into a USB UVC webcam that doesnât use a camera at allâfirst streaming a static test card, then an animated GIF, and finally a real-time Pong game. The ESP32 pre-decodes GIF frames to RGB, JPEG-encodes them, and streams MJPEG, and for the live game it renders to a framebuffer, JPEG-encodes in ~23 ms, and just about hits 30 fps. Thereâs room to optimize (dual-core draw/encode), and this approach is great for dashboards, sensor visualizations, or testing video pipelines. Shout out to PCBWay for the boardsâthey turned out great. 07 March 2026
Why did I fix this? Quick little teardown and bodge-fix: my scratchy-sounding SD card adapter had a wonky contact pin. I cracked it open, tried to bend it back, promptly snapped it, then lost the bit. So I chopped a resistor leg, soldered it in under the microscope, tweaked the pins for continuity, and slapped it back together. Plugged it inâholy crap, it worked! Not the prettiest fix, and I probably wonât trust it long-term, but that was fun. 07 March 2026
I Spent Hours Debugging My Software⊠Quick bench update: I tried to get a 32Ă24 pixel IR module talking over I2C and it just would not play ballâpull-ups, library swaps, address scans, nothing. First silly mistake was not bridging the I2C jumper. Even after fixing that, still dead. Under the microscope I spotted the real issue: poorly soldered pins on the IC. A quick reflow and some IPA cleanup later, it sprang to life. Moral of the story: if yours wonât talk, check the underside soldering. Project video coming soon. 07 March 2026
Drones and Lasers? Itâs been a while since weâve done an unbagging, and Iâve clearly been on an AliExpress bender. Big thanks to PCBWay for fueling the chaos. Todayâs haul: a pair of tiny ESP32âC3 OLED modules (no idea why I ordered two, but here we are), a finger pulse/SpO2 sensor, a USBâC PD trigger with DIP switches that happily serves up 5/9/12/15/20V (1+3 gives 20Vâvery handy), an INMP441âcompatible MS8625 mic, a surprisingly nice transparent clock with temp/humidity, a couple of rechargeable nightlights that only charge on dumb USB because there are no CC resistors, a laser and matching detector (pew pew!), and,... 07 March 2026
Train Surgery I take a fun but unbelievably loud battery train and give it some train surgery: measure the 4xAA pack (~6 V), gut the coal car, shoehorn in an 18650 with a charge/protect/boost board set to about 5.5 V, wire it up, sanity-check polarity, and get the wheels turning. Then I tame the racket by putting a potentiometer inline with the speaker, chop some plastic so the knob pokes out, and hot-glue it all in place. Result: rechargeable power, adjustable volume, same charmâminus the living-room headache. (Quick shoutout to PCBWay for the boards.) 07 March 2026
Three ESP32 Rainbow Boards Failed QA â Can we fix them? Iâm assembling another batch of ESP32 Rainbows: PCB house does the boards, UV silkscreen and some parts, and I finish assembly and QA here in Scotland. I run through three QA failsâno sound, dodgy keyboard, and no USBâthen fix two: the audio fault was lifted pads on the headphone jack, so I bodged it back with flux and solder (speaker and headphones now work, but itâs a spares board). The noâUSB issue was an ESD protection IC sitting off its pad; I reflowed it on a mini hot plate, cleaned up with IPA, verified continuity, and it now enumerates and... 07 March 2026
Stop Using printf() - Debug ESP32 the Right Way Right, letâs give this a go. Instead of drowning in printf()s and blinking LEDs, I show how the ESP32-S3âs builtâin USB JTAG lets you hit Debug in the Arduino IDE (or PlatformIO) and actually step through code. We set breakpoints, add watch expressions, use conditional breakpoints, and even edit variables live with a simple FizzBuzz/LED demo. Itâs quick, it works, and it beats âworks on my machineââjust mind realâtime code and ISRs. Works on ESP32s with native USB. 07 March 2026
I Built My Own ESP32-S3 Board⊠And It Actually Works! I finally assembled my super simple ESP32âS3 dev boardâvoltage regulator, reset button, three status LEDs (5V, 3.3V, and a GPIO blinker), and all pins broken out. I showed two build methods: stencil + hot-plate reflow (quick, with a few USB bridges to clean up) and full hand-solder under the microscope, complete with the rigorous âsolidâ test. Soldered the ESP32âS3 module (skipping the center thermal pad unless you need it), plugged in, got power LEDs, confirmed USB enumeration, flashed a blink sketch, and weâve got a blinking LED. Next up: turning this basic dev board into something more professional for production.... 07 March 2026
I Built a 27V PCB to Fix This $3 Display... I resurrected the LCD writing tablet I blew up last time by designing a dropâin PCB that generates a 27 V pulse to clear the screen. Itâs a regulated dualâjouleâthief variant with two magnetically coupled 20 ”H inductors (soldered opposite ways), a 27 V zener for regulation, inrush limiting, and a few caps and a bleed resistor. I assembled it with PCBWay boards, tried both Volteraâprinted paste and manual SMD under the microscope, salvaged the blister button, and profiled it on the Nordic PPKâpeaks ~18â19 mA, ~7 mA while regulatingâtotally coinâcell friendly. It fits with a bit of mechanical fiddling,... 07 March 2026