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 also the subject of this post.”
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 perform board conversions or let go of their favorite games.
Some months ago, Espressif announced the production of a new chip, named ESP32-PICO-D4.
It’s a complete SiP (System in Package), that is a chip which integrates the esp32 microcontroller, a 4Mbit flash memory, a crystal oscillator, filter capacitors and RF matching links. The chip datasheet is available on the official website.
Using this chip, it’s possible to create very small modules. I recently received one of those from Aliexpress:
To better understand how small it is, let’s compare its size with a “classic” ESP-WROOM-32 module and with a 1 euro coin:
The module includes a chip antenna; it’s also possible to connect an external antenna thanks to the presence of an I-PEX connector.
In conclusion, the availability of the ESP32-PICO-D4 SiP makes it possible to use the esp32 chip in applications where the available space is very small…
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 required for a smart phone to detect when a selfie stick accessory is inserted into a smart phone’s audio jack receptacle using TI audio jack switches TS3A227E and TS3A225E. It shows how these devices respond to common selfie-stick implementations and how to adjust the audio jack switch’s register settings to accommodate both traditional audio accessories as well as the new selfie stick accessory.
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 loss of digital counts.
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 the sd card so what do you do. I recently ran into this problem but luckily I had a serial adaptor on hand to hook up and tell my pi to turn off.
See the full post on his blog and the GitHub repository here.
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 is connected to the internet through WiFi to provide the latest time and gets the ETA for any number of destinations. The travel time is provided by the free Google Directions API interface that includes traffic to give the best estimates on any particular day. The goal is that with an ETA Nixie tube clock, no math is needed to add a rough, often optimistic travel time, to the actual time to determine if we are running late. The clock does that for you and with the power of IOT, is much more accurate! A motion sensor is also added to the clock to turn off the Nixie Tube Display when no one is around, saving power and increasing the Nixie tube lifetime.
It supports CAN bit-rates of up to 1 Mbit/s. The product comes with an open-source SocketCAN driver software. It features a Micro-USB connector and a 4-pin screw terminal with CAN_H, CAN_L, 5-V supply, and ground. The CANable device is a hardware clone of Eric Evenchick’s CANtact project, an open-source USB-to-CAN hardware adapter
A how-to on building a time attendance system with MFRC522 RFID Reader and Arduino from Random Nerd Tutorials:
Before getting started it’s important to layout the project main features:
*It contains an RFID reader that reads RFID tags;
*Our setup has a real time clock module to keep track of time;
*When the RFID reader reads an RFID tag, it saves the current time and the UID of the tag in an SD card;
*The Arduino communicates with the SD card using an SD card module;
*You can set a check in time to compare if you are in time or late;
*If you are on time, a green LED lights up, if you are late, a red LED lights up;
*The system also has a buzzer that beeps when a tag is read.
Before the advent of optical mice, the go to technology was a steel ball which moved two drive shafts to indicate position.
A good example of this is this Microsoft “Intellimouse”.
As expected the electronics are built around a small micro controller
Check out the video after the break.
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