One of the major limitations to I2C is the inherent address conflicts when you try to bus multiple sensors of the same type/family together. While all sensors have a default address, some give an option for a secondary, and fewer give tertiary addresses or beyond. Since most systems only have one I2C bus, you are limited in how many of those sensors are used.
The 9548 family of modules solves this problem: they are multiplexer.
(more…)For general object control, a 6DOF is the most useful IMU, having 3 axises of Accelerometer and Gyroscope. While 9DOF adds a 3 axis magnetometer, those are generally not used for most projects unless you need absolute tracking of magnetic North, and are prepared to have noise filtering from any Electro-Motive Fields near the sensor.
(more…)Sparkfun has made life much easier when working with 7-segment displays. To do so, they made their own PCB which has an Atmel 328P on the back and a 4-digit 7-segment display on the front.
(more…)Node Red is an application built upon NodeJS which supports interfacing the GPIO pins of a Raspberry Pi via a webpage GUI.
It does not require that Apache or PHP be pre-installed, it can also run concurrently with Apache and PHP if they are.
Measuring voltages is a common task in electronics and is accomplished using Analog to Digital Converters. Some microcontrollers and Single-Board computers have them built in, but some do not.
(more…)Shift Registers are a specific type of semiconductor which use bitwise control to toggle outputs. In doing so, a number of outputs can be controlled with minimal wires or programming.
For the examples this document, we’ll be focusing on the Texas Instruments 6b595, which has been replaced by the 6b596 and 6b598-Q1. They all function the same, but the manufacturing architecture and packages have been updated.
The xBee family of products, made by Digi International, are very useful for short-to-medium range communication. They support Point-to-Point (PtP; P2P) and Point-to-Multi-Point (PtMP; P2MP) communication and have multiple communication modes.
XCTU is the configuration software for the xBee family of products.
https://www.digi.com/products/embedded-systems/digi-xbee/digi-xbee-tools/xctu
Accelerometers, by definition, are used to measure how fast an object is accelerating. While this is traditional in the horizontal X/Y plane, adding the Z axis can unlock a whole new level of capabilities – especially for orientation sensing.
(more…)In the world of microcontrollers and semiconductors, one thing will never go away: The need to open or close a circuit. There are multiple types and formats of these electromechanical interfaces.
(more…)One of the most common hurdles to running a Raspberry Pi headless is having a way to shut it down gracefully.
Fortunately, there is a little-known built-in toolkit for doing exactly that.