Vintage computer Tandy 1000 upgrade @ smbaker.com: A Tandy 1000 was the second computer that I owned, the first was a Tandy CoCo. Note that I keep a slightly different mental “computers that I owned” list and “computers that I used list”. There are a few computer I was able to gain access to and […]
Author Archives: DP
App note: Probing oscillator output
This application note from SiTime gives practical guidelines for the effective probing of oscillator output, shows common mistakes and explains how to identify and avoid potential probing issues. Link here (PDF) Electrical engineers often use oscilloscopes for purposes ranging from checking simple, lowspeed digital signals to accurate waveform and jitter measurements. They need to use […]
App note: Definitions of VCXO specifications
App note from SiTime about Voltage controled crystal oscillator (VCXO) specification, Link here (PDF) VCXO are frequency control devices that allow change of output frequency as their input voltage varies. In selecting a VCXO for any application, a number of device performance specifications must be considered. This application note attempts to clarify the key VCXOspecific […]
Hotkey keypad from cash register
Fwacer shared detailed instructions of how to build this shortcut keyboard from an old cash register, project instructables here. More details at brycedombrowski.com.
Tiny transformer inside: Decapping an isolated power transfer chip
Ken Shirriff writes: I saw an ad for a tiny chip1 that provides 5 volts2 of isolated power: You feed 5 volts in one side, and get 5 volts out the other side. What makes this remarkable is that the two sides can have up to 5000 volts between them. This chip contains a DC-DC […]
#FreePCB via Twitter to 2 random RTs
Every Tuesday we give away two coupons for the free PCB drawer via Twitter. This post was announced on Twitter, and in 24 hours we’ll send coupon codes to two random retweeters. Don’t forget there’s free PCBs three times a every week: Hate Twitter and Facebook? Free PCB Sunday is the classic PCB giveaway. Catch […]
Dual PA5030 Integrated amplifier faults and fixes
Doz did a repair of a Dual PA5030 Integrated amplifier and documented the whole process on his blog.
12V 25A power supply
Stynus blogged about his 12V 25A power supply: To test my LED Stair Lighting Controller boards I needed a 12V power supply that can deliver a lot of current. For this I chose a SP-320-12 from meanwell. However with the screw terminals it is not easy to use on a lab bench, also there is […]
App note: Human interface device tutorial
Silicon Lab’s basics of USB Human interface device (HID) and how this class communicate to PCs. Link here (PDF) The Human Interface Device (HID) class specification allows designers to create USB-based devices and applications without the need for custom driver development.
App note: Integrated supercapacitor charger
Application circuit of supercapacitor ENYCAP(TM) power management from Vishay. Link here (PDF) The MAL219699001E3 demonstration circuit is a fully transparent power management solution with a regulated 2 W output and integrated power backup. It provides a DC/DC regulator with a wide power input range from 4.0 V to 20 V and adjustable regulated output between […]
Cloning a 6502 Apple-1 in just 930 logic gates
Turning 930 logic gates into a working 6502 Apple-1 clone: Two years ago, the Gigatron arrived on the retrocomputing scene. It needs just 930 logic gates (packed into 33 standard 7400-series ICs) to create a computer that beat ‘complex’ 1980s home computers like the VIC-20 in terms of both CPU power and graphics. Without microprocessor, […]
Making an unusual and beautiful single-digit clock
A DIY single-digit clock using Arduino Nano, RTC and 3D printed 7-segment digit: Generally at whatimade.today we post original projects we dream up ourselves. Today’s post is a little different. We’re going to describe how we constructed Mirko Pavleski’s single-digit clock. We made it because it’s a fun project, wonderfully impressive to look at, and […]
Reverse-engineering the audio amplifier chip in the Nintendo Game Boy Color
Ken has written an article on reverse engineering the audio amplifier chip in the Nintendo Game Boy Color: The Nintendo Game Boy Color is a handheld game console that was released in 1998. It uses an audio amplifier chip to drive the internal speaker or stereo headphones. In this blog post, I reverse-engineer this chip […]
Broadlink smart bulb conversion to open source
VikTak writes: Many of the current bulbs on the market are based on the same chip, the ESP8266. These bulbs are very easy to “hack” and replace the firmware in them with the likes of my ActoSenso or the more widely known and used Tasmota. However, not all bulbs use the same chip. One of […]
#FreePCB via Twitter to 2 random RTs
Every Tuesday we give away two coupons for the free PCB drawer via Twitter. This post was announced on Twitter, and in 24 hours we’ll send coupon codes to two random retweeters. Don’t forget there’s free PCBs three times a every week: Hate Twitter and Facebook? Free PCB Sunday is the classic PCB giveaway. Catch […]
NRI G-13.mft parallel coin acceptor to Serial adapter
David has been working on an ATmega based USB serial adapter for the NRI G-13.mft coin validator: The NRI G-13.mft by Crane is a versatile and high secure coin validator. It can be programmed using the propretary WinEMP software and PC interface, or event it has some DIP Switch that can be used to program […]
App note: Design of a 100W active clamp forward DC-DC converter for telecom systems using the NCP1562
Another DC-DC converter design using ON Semiconductor’s NCP1562 PWM Controller. Link here (PDF) The NCP1562 PWM controller contains all the features and flexibility needed to implement an active clamp forward dc−dc converter. This IC operates from an input supply up to 150 V, thus covering the input voltages usually found in telecom, datacom and 42 […]
App note: Power-handling capabilities of inductors
App note from Coilcraft on how to calculate the power dissipation of an inductor. Link here (PDF) Inductors are not typically rated by power, however an approximation of the power-handling capability of an air core or ceramic core chip inductor can be estimated using the data sheet specifications for current and resistance.
Commodore 64 for STM32F429 Discovery board
Dave built a Commodore 64 emulator for STM32F429 Discovery board: Yeah, the LCD is tiny at 2.4″, and the emulation runs about 15% slower than an NTSC C64. But it’s running on a small embedded board that’s available for under $30 US (DigiKey, Mouser, …) including mounted LCD display and USB OTG jack. Just add […]
Face tracking robot with an ESP32-CAM
An ESP32-CAM face follow bot @ robotzero.one: I wanted to add face tracking to the robot so it could follow a person around the house. I added an ESP32-CAM camera module, mounted with 3d printed parts and connected via cables to serial on the Arduino Nano on the Robot. Check out the video after the […]