smbakeryt built his own Hayes Chronograph: I’ve always wanted a Hayes Chronograph, but have never been able to acquire one, so I finally broke down and just made my own. The Hayes Chronograph was a compliment to Hayes line of smart modems, and implemented a real time clock for computers that didn’t have a built-in […]
Dilshan has published a new build: μSim is a lightweight PIC™ CPU and ALU simulator. This simulator supports the PICmicro mid-range instruction set and designed to work on both PC and Arduino platforms. Compare with most of the other emulators, μSim does not provide all MCU features and peripherals. This simulator design as a minimalistic […]
App note from FTDI/Bridgetek demonstrating LED control over Ethernet. Link here (PDF) In an increasingly connected world, more and more devices are going online. To enable online connectivity typically requires an MCU with Ethernet or Wi-Fi capabilities. To demonstrate the principle, this Application Note describes an implementation of a web server which allows for control […]
App note from FTDI/Bridgetek on simple implementation of external power switch for RTC power hand-over. Link here (PDF) The Texas Instruments SN74AUC2G53 Single-Pole Double-Throw (SPDT) analog switch is used to select the power supplied by the 1.5V battery or by the 1.2V internal LDO.
100 MHz third overtone crystal oscillator @ DIYfan: Couple of years ago I purchased from a local store 100 MHz crystal resonator and tried several times to make a working schematic on breadboard using standard circuits I found on the internet. It never worked good enough, usually oscillating at 33.3 MHz instead of 100 MHz. […]
An update on Chaac weather station project we covered previously: With this latest redesign, I made a few more changes. First of all, I decided I would no longer be afraid of LoRa and put in a LoRa radio module. This will, with the right firmware, allow for standalone operation using LoRaWAN and The Things […]
Gwen, NG3P, has been working on a power source project for field ham radio operating: We’re coming up on a confluence of two things: Nice weather, and relaxing of the Covid-19 lockdowns in much of the United States. This means more hams leaving their home shacks and taking their operating to the field. For some, […]
High speed board design app note from ON Semiconductor. Link here (PDF) There is an increase of devices and circuitry in usage of high speed, low consumption, small volume and lower interference. Hence PCB design is an important stage of electronic product design. It forms a connection between function and electronic components, and is also […]
Tech note from Vishay on polypropylene film capacitor value calculation with temperature and power dissipation consideration. Link here (PDF) Film capacitors can deliver high power density due to their low ESR and high ripple current capabilities, and offer the highest ampere per μF ratio of capacitor technologies. This feature, combined with their high reliability and […]
DIY MechBoard64 @ breadbox64.com: When the MechBoard64 was finally realized and presented on my blog, it soon came clear that a new mechanical keyboard was the missing piece in the creation of a brand new Commodore 64 (…well that and some new keycaps…). As I have no intention to become a Commodore 64 mechanical keyboard […]
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 […]
Peter (DK7IH) blogged about his 14MHz shirt-pocket SSB transceiver.
Michael posted detailed instructions of how to set up your A4988 stepper motor driver’s motor current limit: One important thing to set up when using these drivers is the motor current limit. This is especially important when you’re using a higher input voltage than what the motor is rated for. Using a higher voltage generally […]
Board design considerations like board thickness and layer stacking under a crystal when designing PCB for accurate clock crystals discuss in this app note from Maxim Integrated. Link here Crystal oscillator is widely used in RTC applications. Clock accuracy, one of the key parameters in real-time clocks, partly depends on the parasitic capacitance of the […]
App note from Maxim Integrated about the design of modern ventilator system. Link here This application note provides an overview of ventilator systems with a focus on system design for precision measurement and reliable protection. It discusses the four key components of a pneumatic ventilation system: gas supply, gas flow mixture, inhalation and exhalation systems. […]
Reverse-engineering and comparing two game boy audio amplifier chips @ righto.com The Nintendo Game Boy contains an audio amplifier chip for sound through a speaker or headphones. In this post, I reverse-engineer this chip and compare it with the later Game Boy Color chip (reverse-engineered earlier). Unexpectedly the Game Boy Color uses an entirely different […]
David @ Rowetel writes, “My initial goal for this work is a “100 kbit/s IP link” for VHF/UHF using Codec 2 modems and SDR. One application is moving Ham Radio data past the 1995-era “9600 bits/s data port” paradigm to real time IP.” See the full post at rowetel.com.
cpldcpu writes: A chaotic oscillator is an electronic circuit that can exhibit “chaotic“, nonperiodic behavior. A commonly cited example is Chua’s circuit, but there are many others. I always regarded these as carefully designed, rather academic, examples. So I was a bit surprised to observe apparently chaotic behavior in a completely unrelated experiment. See the […]
FlorinC’s HDSP clock with SCD5583 display: Here is another interesting “intelligent” LED matrix display, whose name actually makes some sense (unlike HDSP-2354, among many others): SCD5583A. I reckon it means: “Serial Character Display with 5x5x8 dot matrix”. 3 is the code is for green (0 for red, 1 for yellow). More details on Wise time […]
Drive WS2812B LED strips from a PMOD device, a lightdriver project @ anfractuosity.com: I created a PMOD module PCB using KiCAD, that enables connecting WS2812B lighting strips to an FPGA board with a PMOD interface. The board was assembled by JLCPCB. This is my first project using an FPGA, I plan to soon implement an […]