Every Friday we give away some extra PCBs via Facebook. This post was announced on Facebook, and on Monday we’ll send coupon codes to two random commenters. The coupon code usually go to Facebook ‘Other’ Messages Folder . More PCBs via Twitter on Tuesday and the blog every Sunday. Don’t forget there’s free PCBs three […]
Author Archives: DP
Emulating a hardware ROM in real time with an STM32F4
ROM emulation using an STM32F4: I remember reading dhole’s Emulating a GameBoy Cartridge with an STM32F4 some time ago thinking that it had a lot of applications with respect to old computers. In that article a STM32F4 microcontroller ‘pretends to be a ROM chip for a gameboy’. At the start of a bus cycle, […]
Bit-bang FTDI USB-to-serial converters to drive SPI devices
Scott W Harden writes , “The FT232 USB-to-serial converter is one of the most commonly-used methods of adding USB functionality to small projects, but recently I found that these chips are capable of sending more than just serial signals. With some creative programming, individual output pins can be big-banged to emulate a clock, data, and […]
Free PCB Sunday: Pick your PCB
We go through a lot of prototype PCBs, and end up with lots of extras that we’ll never use. Every Sunday we give away a few PCBs from one of our past or future projects, or a related prototype. Our PCBs are made through Seeed Studio’s Fusion board service. This week two random commenters will […]
App note: How to select an ambient light sensor for your end equipment
Another application note from Texas Instruments about ambient light sensors and how to effectively use them. Link here (PDF) Generally, when someone thinks of trying to design a system with an ambient light sensor there are four main concerns or problems that need to be addressed. The most important features of an ambient light sensor […]
App note: How to isolate signal and power in isolated CAN systems
CAN system isolation app note from Texas Instruments, Link here (PDF) With the increase in the usage of signal isolation in many industrial and automotive applications, the need for isolated power has also increased. The benefits of isolation are lost if the power supplies on either side of the isolation barrier are simply shorted. At […]
ESP32 and the CWTD ‘Test gadget’
DuWayne published a new build: I have been following a series of podcasts from ‘Chatting with the Designers’ CWTD.ORG that cover building simple Arduino based test equipment. I decided that this would make a nice way to get into development with the ESP32. The CWTD ‘Test Gadget’ is basically an Arduino Nano with a 2 […]
Siglent SDG6000X Series Arbitrary waveform generator review, teardown and experiments
A closer look at the newly released Siglent SDG6000X Series Arbitrary Waveform Generator from The Signal Path: The full teardown of the unit reveals the internal architecture of the instrument, DAC / FPGA interconnect as well as the output amplifier structure. Although the limitations of the FPGA prevents the instrument to operate at full 2.5GSa/s in arb-mode, […]
Transistor radio series: the AF power amp
Vasily Ivanenko @ QRPHB writes, “I sought a low distortion, single supply, AF power amplifier for my transistor radios. I’ll present my experiments, some musings, test equipment and a reference to some wonderful books & their wise author. Sadly, some amateur radio receiver builders diligently craft their RF stages, but skimp on the PA audio stage. […]
Presenting the single ESC key USB keyboard
Glen Akins shares his latest build the single ESC key USB keyboard: After building the “awesomely impractical” giant three-key keyboard, I decided it was time to build something a bit more practical—presenting the single ESC key USB keyboard! This keyboard has exactly one function which is to provide an optimal ESCing experience regardless of whatever […]
#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 […]
An easy way to mount DS18B20 temperature sensors
Matt wrote an article describing a technique he used to mount DS18B20 temperature sensors: One of the biggest advantage of these sensors over I2C sensors, is that you can mount them almost anywhere. That having been said, I’ve never quite managed to come up with an elegant solution, particularly when attaching to a heatsink (for […]
Minimalistic 1D pong
Here’s a minimalistic 1D Pong game from Vagrearg: How little do you need for a game An exercise in futility. That is what many would call this endeavor. How few elements (signifiers and affordances) do you need to not only recognize a game for what it is, but also are able to play it? The […]
5 LDO regulator considerations other than voltage and current
James Lewis over at Bald Engineer writes, “For an AddOhms series, I created a DIY Arduino I am calling the “Pyramiduino.” It is an ATmega328p based board in the shape of a triangle. Other than being cute, the shape does not offer any other benefit. The design features a 3.3 volt LDO Regulator, which is […]
A journey into Capcom’s CPS2 silicon – part 3
Eduardo Cruz published the third and last post in the Capcom CPS2 reverse engineering series we covered previously: For many years, finding how and where did Capcom hid away its security implementation has been a pending critical task for the arcade community. CPS2 systems running out of battery were rendered useless forcing collectors worldwide to […]
Free PCB Sunday: Pick your PCB
We go through a lot of prototype PCBs, and end up with lots of extras that we’ll never use. Every Sunday we give away a few PCBs from one of our past or future projects, or a related prototype. Our PCBs are made through Seeed Studio’s Fusion board service. This week two random commenters will […]
App note: Detecting selfie sticks using TI audio jack switches TS3A227E and TS3A225E
Old app note from Texas Instruments on smart phone selfie sticks button detection. Link here (PDF) Selfie sticks are becoming as common of a smart phone accessory as a pair of headphones. Because of the selfie stick’s increasing popularity, smart phone manufacturers need to be able to accommodate the accessory. This report describes the procedure […]
App note: EMI-hardened operational amplifiers reduce inaccuracies
EMI reduction built-in on op amps, app note from Texas Instruments. Link here (PDF) Operational amplifiers (op amps) with electromagnetic interference (EMI) filters can reduce significant errors. These types of errors are not always obvious to the system designers. They often impact the signal chain, in particular the analog-to-digital converter in the form of a […]
PI serial adaptor
Raspberry pi serial adaptor from Facelesstech: If you spend a lot of time building things with a raspberry pi you will eventually run into the problem that you have booted your pi it’s not plugged into a tv/monitor and it’s not connected to wifi. You don’t want to just turn it off because it could corrupt […]
ETA Nixie tube clock
Mark Smith over at surfncircuits has a nice write-up about building an ETA Nixie Tube Clock: This DIY project will combine the estimated time of arrival function with a Nixie tube display to create an estimated time of arrival (ETA) Nixie tube clock. It is all easily controlled by a Raspberry Pi Zero W that […]