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Month: February 2017

Control and Distribution of Power – ATX and Pi

Control and Distribution of Power – ATX and Pi

The sensors and devices that I plan to control are located several meters from each other. This is just the nature of things. If I want to successfully deploy and reliably use the system, it means I’ll have to reconsider how everything is powered. The bench in my lab allows me to use AC adapters to power the devices. The wall outlet is nearby and I don’t have to fuss so I can focus on other things. This isn’t true…

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I2C – Squaring up multi device communications

I2C – Squaring up multi device communications

UART and SPI communication have benefits and limitations.  UART is confined to point to point links, whereas SPI requires additional slave select channels from the master.  Both do not scale well for multiple devices.  For that reason, I2C was developed with the introduction of device addressing in the data channel. I2C stands for Inter-integrated Circuit and it uses a clock channel to synchronize its data channel.  Only two wires are required to achieve this.  They are defined as SDA for…

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SPI vs SPI – Serial Peripheral Interface

SPI vs SPI – Serial Peripheral Interface

The UART serial communication method discussed in my last post showed a limitation of scale.  Asynchronous serial data can should only be point to point.  If many devices are required, the complexity of design and cost increase. The Serial Peripheral Interface, or SPI protocol, is a method to reduce the complexity and costs of scaling.  In contrast to UART, SPI does not require complex bridgeheads.  Receiving devices need nothing more than a shift register to operate. Without going into too…

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Serial Communications

Serial Communications

Ideas and thoughts are shared with people through speech, text, or some other form of communication.  This is how one knows, or at least has some idea of, what the other is thinking.  Electronic devices are similar.  Without communication, devices and people would be isolated in the cosmos.  Like language, devices use sets of standards and protocols to accomplish communication. In this post, I’ll introduce briefly parallel communication.  Next I’ll be covering the most fundamental communication methods of serial communication. …

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