Here’s one of the last board I design the last year. On 2016, I develop the Dual USB Serial and I2C Converter board. Although this board works fine, it has a couple of lacks. First one, is that to use the both converters, you need two free USB ports. Is a minor problem today with USB hubs, but you need the hub and also two USB wires. And the other problem is that this board uses mini-USB connectors. Of course today you can still find it, but aren’t as common as the micro-USB wires. For this two reasons, I decide to upgrade the board, add the micro – USB connector and put a USB hub inside it. Because I choose a 4-port USB hub, I use also 4 USB serial converters. With some addons, you can select power supply value (5V, 3V3), serial levels (TTL, RS232) and GPIO functions in an independent way for each converter. So, let’s see how works this USB Serial Star, a 4 in 1 USB to Serial and I2C Converter.
Kerry Wong did a teardown of an old analog piezoelectric vibrating gyroscope:
Gyroscopes nowadays are based on micro-electro-mechanical systems (MEMS) technology. They are low cost and extremely miniaturized. A device combing both a three-axis gyroscope and a three-axis accelerometers (sometimes these devices are referred to as 6DOF devices) such as the MPU-6500 for example can be had in a QFN package as small as 3 mm x 3 mm and under 1 mm in height. Before these MEMS devices gained mainstream popularity however, larger piezoelectric vibrating gyroscopes were used in many consumer electronics devices.
To expand my microcontroller and programming knowledge I have decided to try and make a Solar Powered Weather Station. My goal is to record parameters like:
*Air quality (something to do with CO or CO2)
I then hope to send (wirelessly) the data to a base station and log/display it on a simple website. To make things interesting I also aim to power the data gathering station from a large supercapacitor (~100F), and in keeping with my solar tradition the supercapacitor will be charged from a solar-cell.
App note from Richtek on how to work with Li-ion batteries properly. Link here
Lithium-ion/polymer rechargeable batteries, which have been widely used today, have distinguished properties, but are very delicate and have to be used with extreme care. Improper use of Li-ion batteries will bring about catastrophic consequences. The incidences of burning and explosions of Li-ion batteries have often been heard. Carefully understanding their properties and adopting a right battery management method is most essential for making good use of Li-ion batteries.
When it was launched the new Arduino Yun (named Rev.2) and the Yun Shield, the Linux distribution running on the board, OpenWrt, was updated as well. In particular, a key component for Irrighino has been replaced with its newer version, the php engine.
If you own a “first generation” Arduino Yun and you’d like to test the new functionalities shipped with Rev.2, in this post I explain how you can update the operating system of your board!
The commands you have to issue on your Yun to install all the required components for Irrighino now are:
In this project we build simple I2S stereo decoder with amplifier. To decode I2S data we use Princeton Technologies PT8211 16bit DAC. KA2206 audio power amplifier is used as driver stage of this system.
Structure of this I2S amplifier is self-explanatory from the schematic. We select PT8211 and KA2206 combination due to lower cost and availability. Unfortunately PT8211 DIP package is not available in local market and we use SO package in our prototype. We design PCB for the DIP packages, and therefore we solder PT8211 SO package to PCB using “SO8 to DIP8” converter.
As the name implies, a transmit converter takes another frequency – such as that produced by a conventional HF transceiver – and converts it to another frequency. In my case I use an FT-817 – a low-power (5 watt) all-mode, all-band transceiver that is a favorite for VHF, UHF and microwave enthusiasts that use transverters. Because of its small size, feature set and already-low output power, it is a natural to be used in this application.
Dr. Beddow’s instrumentation class has been building the 2016 version of the Cave Pearl datalogger for more than three years, and feedback from that experience motivated a redesign to accommodate a wider range of student projects while staying within the time constraints of a typical lab-time schedule. The rugged PVC housing from the older build has been replaced with an inexpensive pre-made box more suitable for “light duty” classroom deployment. The tutorial includes a full set of youTube videos to explain the assembly. We hope this simplified build supports other STEM educators who want to add Arduino-based experiments to their own portfolio of activities that develop programming and “maker” skills.