diy electronics
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How to use ESP32 Deep Sleep Mode for Low Power Consumption We have built several ESP32 projects using different ESP32 development boards. But these boards come with a power-saving mode called deep-sleep mode. Let's try to understand deep sleep on the ESP32 with an example. Take an example of a laptop. When it's in use, the fans spin at high speed, the display is on, some apps run in the background, and the battery drains… |
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A Supermarket Solar Light Charged Its Unprotected Li-ion Cell to 4.8 V on a Sunny Day Cheap solar wall lights are on millions of walls, and most people never think about the battery inside. YouTuber DiodeGoneWild opened one that was sold in a Czech supermarket, by a Czech company, with a PIR motion sensor, an "IP44" rating and an 18650 Li-ion cell. What he found inside led him to title the video "LED Solar Sensor Houseburner". No charger,… |
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How to Build a DIY Digital Oscilloscope using STM32 Microcontroller An oscilloscope is the one instrument every electronics engineer reaches for when a circuit misbehaves. A multimeter tells you a single number, but an oscilloscope shows how a voltage changes over time: the shape of a PWM signal, the bounce of a switch, or the ripple on a sensor output. Bench oscilloscopes are expensive, though, and the best way to understand how one… |
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A Maker Saved Two Wind Gauges From a Demolished Airport Tower and Gave Them an ESP32 Brain When his local airport tore down its old control tower, one maker got the chance to salvage two vintage wind meters from the controllers' console: a wind speed dial (0-100 mph) and a wind direction dial (0-360 degrees), both heavy steel cans with glass faces and night lamps. Instead of putting them on a shelf, he made them show live wind again, fed from his own weather station and driven by a… |
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How to Build an ESP32 Offline Speech Recognition Speech recognition models like OpenAI’s Whisper offer high levels of accuracy, but their base model itself consumes up to 140MB and running them on a low-end device like an ESP32 is difficult. In this tutorial, we are going to run Cactus Compute’s Whistle Speech-to-Text Model launched on 2nd of October 2026. The actual size of the model is 16.9MB, which won't fit… |
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This Pocket AI Assistant Fits Between Two Fingers: An ESP32-C3, an OLED and a Brass Frame Most DIY AI voice assistants end up as a dev board in a plastic box. Huy Vector of HVT Lab went the other way and built a talking assistant about the size of two fingers, soldered into an open frame of brass wire and tubing. An ESP32-C3, a 0.96-inch OLED face, a microphone, a smartphone speaker and a rechargeable battery are all it takes to hold a spoken conversation. … |
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A $23 Used Phone's Motherboard Becomes the 4G Video and Control Link for This RC Plane Most RC planes lose their link a few kilometres out, because a normal 2.4 GHz radio only reaches so far. Mountain DS Lab took a different route: an 8-year-old Xiaomi Mi 8, bought used for $23 with a cracked back and a damaged screen, stripped down to its motherboard and fitted inside a foam RC plane. The phone's own LTE modem now carries both the live FPV video and the control commands over… |
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How to Run Wikipedia Offline on ESP32 These days, we are heavily dependent on cloud computing, high-speed internet and all. We rarely think about what happens if the internet goes down or what happens in areas where the network is not reachable or information access is very difficult. The main solution is having the data and its processing locally so that they are reachable anytime, even without internet… |
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A $35 Raspberry Pi Replaces a $50,000 Broadcast Tape Deck in This DIY 1990s TV Station Built From Six Pis and Two Picos The analog TV signals that old tube sets need stopped being broadcast almost 20 years ago, so when BorisDigital bought a 1995 Sony Watchman pocket CRT TV for 15 dollars at a thrift store, it had nothing to watch. A cheap analog TV transmitter board fixed that. Then he kept going. The result is a full 1990s-style TV station in a 10-inch home lab rack, built from six Raspberry Pis, two Raspberry… |
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This DIY ESP32 Soundbox Announces Real UPI Payments in About 2 Seconds, No Merchant Account Needed Walk into almost any shop in India and you will hear it: a small speaker on the counter calling out "Rs 10 received" the moment a customer pays by UPI. Makers have built their own versions before, but almost all of them need a merchant account with a payment gateway, which most students and hobbyists simply don't have. Now techiesms has built an ESP32 payment soundbox that skips the merchant… |
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This DIY ESP32 Music Player Combines Bluetooth, MicroSD Storage, and a CNC-Machined Aluminum Body With a Brass Knob HVT Lab recently built a custom portable music player using an ESP32 microcontroller, combining local music playback, rotary encoder controls, and Bluetooth connectivity in a compact retro-inspired design. The project allows users to load their favorite songs onto a microSD card and play them through a 3.5 mm headphone jack. An OLED display provides a simple interface, while a rotary encoder… |
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Smart Contactless Water-Level Monitoring System Using SemLab-CLS-24BP The SemLab Contactless Liquid Level Sense Module is an open-source, liquid level sensor designed for non-invasive fluid detection. By utilising capacitive sensing, the sensor detects the presence of liquid inside a container or pipeline without making direct contact with the fluid. This non-contact design prevents sensor corrosion, contamination, and degradation… |
