Ken has written an article on reverse engineering the first FPGA chip, the XC2064: The FPGA was invented by Ross Freeman1 who co-founded Xilinx2 in 1984 and introduced the first FPGA, the XC2064. 3 This FPGA is much simpler than modern FPGAs—it contains just 64 logic blocks, compared to thousands or millions in modern FPGAs—but […]
Author Archives: DP
App note: RS-485 communication link vs. the electric fence, A demonstration of RS-485 EMC robustness
Analog Devices’ RS-485 robustness demonstration by direct application of HV transient to the communication line. Link here Industrial and instrumentation applications (I&I) require transmission of data between multiple systems, often over very long distances. The RS-485 bus standard is one of the most widely used physical layer bus designs in I&I applications. Applications for RS-485 […]
App note: Using ESD diodes as voltage clamps
App note from Analog Devices on improving robustness of an amplifier by determining and mitigating internal ESD diode clamp electrical overestress. Link here When external overvoltage conditions are applied to an amplifier, ESD diodes are the last line of defense between your amplifier and electrical over stress. With proper understanding of how an ESD cell […]
App note: Notes for temperature measurement using forward voltage of PN junction
App note from ROHM Semiconductors about the cautions when measuring temperature from PN Junctions. Link here (PDF) The forward voltage of a pn junction can be measured to estimate the junction temperature of a semiconductor device. However, correct results may not be obtained if the measurement is performed incorrectly.
App note: What is a digital transistor?
See the simple composition of a digital transistor, app note from ROHM Semiconductors. Link here A digital transistor is a bipolar transistor that integrates resistors. Bipolar operation tends to become unstable if the input (Base) is connected directly to the output terminal of an IC for voltage control. Inserting a resistor at the Base stabilizes […]
A full-duplex tiny AVR software UART
Nerd Ralph writes: I’ve written a few software UARTs for AVR MCUs. All of them have bit-banged the output, using cycle-counted assembler busy loops to time the output of each bit. The code requires interrupts to be disabled to ensure accurate timing between bits. This makes it impossible to receive data at the same time […]
Back to basic – Mini CNC plotter
tuenhidiy shared detailed instructions of how to easily build your own low-cost Arduino mini CNC plotter from old DVD/CD player, project instructables here. I have become too concerned with complicated details or new things, and now I should concentrate on basic, simple and important ideas. Getting back to basics, to start learning CNC, today I’d […]
Convert an ATX computer supply to a bench power supply
Using an old computer ATX power supply as a high-performance workbench power supply @ DroneBot Workshop: A Bench Power Supply is an essential component for any serious electronics experimenter. But a good supply with multiple output voltages and a high current capability can set you back some serious cash. In this article we’ll look at […]
App note: Advantages and limitations of the chopper-stabilized architecture of zero-drift precision op amps
App note from ON Semiconductors on the do’s and don’ts when using zero-drift precision op amps. Link here (PDF) Zero−drift precision op amps are specialized op amps designed for applications that require high output accuracy due to small differential voltages. Not only do they feature low input offset voltage, but they also have high CMRR, […]
App note: A method of enabling more touch pads With 5-ch CapTouch module on LPC804 MCU
App note from NXP demonstrating capacitive pin channels expansion on LPC804 MCU with SWM (switch matrix) and scan sequences. Link here (PDF) The CapTouch module on LPC804 supports only 5 channels by hardware. Normally, the device with up to 5 channels can fulfill some simple use cases. But if more channels are required by the […]
App note: SPI flash programming algorithms for LP546xx
App note from NXP giving step by step guide on creating flash programming file for MDK and also using pre-compiled flash programming algorithm which can be used directly. Link here (PDF) LPC546xx has external spi flash interface(SPIFI) which can R/W external flash with single/dual/quad mode. It also supports XIP mode which means code can be […]
Oscillatoscope2e
Oscillatoscope2e @ gieskes.nl Oscillatoscope2e is a eurorack version of Oscillatoscope2. It is the same, only the audio output is DC coupled and 10v peak to peak. For Oscillatoscope2 see here. Check out the video after the break.
Yaesu FT-817 companion display
Andy (G7UHN) over at SWLing Post has written an article detailing the build of his genius companion control display for the Yaesu FT-817 transceiver: Like so many I love getting out portable with my FT-817 but I do seem to spend so much of my operating time fiddling through the soft-keys because my most used […]
App note: Measurement, calibration and measurement uncertainty of OSRAM Opto Semiconductor LEDs
App note from OSRAM focuses on the measurement of LEDs and provides a fundamental understanding of optical measurement, calibration and measurement uncertainty. Link here (PDF) With the recent rapid growth of the LED market and the development of its applications, LEDs have become more common. They can now be found in many new applications within […]
App note: Health monitoring
App note from OSRAM on design recommendation for LEDs and photodiodes intended for health monitoring. Link here (PDF) Wearable applications enable the monitoring of vital signs for healthcare reasons and also for daily life activity tracking. This application note provides basic information on health monitoring as well as an overview of the potential products and […]
DIY portable video conference, sharing and teaching device
A DIY conference and teaching device @ mcuoneclipse.com: COVID-19 is by far not over, and in Switzerland the infection rate is going up again (2nd wave?). During the spring 2020 semester university lock-down we moved pretty much everything to a ‘distance learning’ setup. With that experience and with the request to prepare for the fall […]
M17 open source radio
Wojciech Kaczmarski (SP5WWP) and his team have been working on the M17 open source digital radio project: Open source handheld for a novel digital communication standard called M17. The goal here is to kick the proprietary protocols off the airwaves. To do that, it’s not just good enough to be open, it has to be […]
Build your own HF balun
Miguel, EA4EOZ, posted this great DIY tutorial on building your own balun: A balun is a MUST for dipoles or similar antennas when they are feed with coaxial cables. Many hams connect the center conductor of the coaxial cable to one side of the dipole, and the shield to the other. Wrong!From the RF point […]
App note: Charging capacitive loads with eFuse
App note from ON Semiconductors on how eFuse manage to cope up with large capacitive loads. Link here (PDF) The eFuse protection devices are used for limiting the system load current in the events of overload or short circuit. Many applications employ On Semiconductor eFuses at the power input stage of the system between the […]
App note: Tuning linear redrivers
App note from ON Semiconductors about linear redrivers setting. Linear redrivers are used in systems in order to improve high speed signal integrity in systems transmitting digital data. Link here (PDF) Linear redrivers are used in many applications that transmit data at high speeds. They can be found on computer motherboards, gaming consoles, graphics cards, […]