Raspberry Pi serial port: Ribbon or no ribbon?
The interest in an RS-232 serial port for the Raspberry Pi has LAVA considering making a simple GPIO-to-RS-232 DB-9 serial port board. This little item would plug onto the Raspberry Pi’s GPIO pin header, take the Raspi’s UART signals up to RS-232 levels, and present them on a conventional DB-9 (aka DE-9) connector. It would [...]
read moreRS-232 Serial Crossover Cables
The range of serial cabling includes crossover cables, sometimes called null modem cables. This post fills out the information on crossover cables, as at times confusion about them can cause systems not to work. When two pieces of Data Terminal Equipment (terminals, or DTEs) need to be connected to each other, or two pieces of [...]
read moreRS-232 full voltage range
When it comes to RS-232 electrical characteristics, there is one important thing to note: the voltage range for signalling in RS-232 is very wide, from 3 to 15 volts, plus or minus. The implication is that designers of serial port boards, such as LAVA, have wide latitude for electrical design, according to the specification. In [...]
read moreRS-232 voltages
Recently, while blogging on the Raspberry Pi computer board, I’ve been reminded of the importance of paying attention to serial port voltage levels. While voltage levels are a general consideration for all electronics, I’ll just talk about RS-232 voltage levels, since speaking of voltage levels can be a bit tricky particularly with RS-232. Taking the [...]
read moreMore on Raspberry Pi serial ports
This blog posting on the Raspberry Pi serial ports goes into a bit more detail than the last post on Raspberry PI serial interfacing, as it compares the two serial ports the Raspberry Pi has and looks more closely at the characteristics of the second serial port available on the Raspberry Pi. Of course, for [...]
read morePLC Programming
Serial port connection to PLCs Programmable Logic Controllers (PLCs) are a specialized variety of computer typically used for controlling machinery on assembly lines and other systems needing mechanical and electrical robustness. They provide industrial-grade levels of immunity to electrical noise, precisely deterministic timing, and the ability to operate in a wide range of temperatures. They [...]
read moreRaspberry Pi serial interfacing
The Raspberry Pi, the single-board computer that has been causing so much excitement lately, has actually got two serial ports. One is a “mini-uart” with interfacing built into the Raspberry Pi’s GPIO (General Purpose Input-Output) interface. The GPIO interface is a pin header, and the relevant serial port pins are as shown: The Raspberry [...]
read moreCustomized Parallel-PCI
LAVA’s Parallel-PCI card is well-regarded for its speed and compatibility in many systems and applications, but every so often someone needs something special. In the case of Lockheed Martin, as they were developing a system for the US Postal Service they uncovered the need for a parallel port card that delivered a particular output voltage [...]
read moreParallel Port Control of Plasma Cutter
The parallel port is a crucial part of the control system for plasma cutters, such as those manufactured by PlasmaCAM in Colorado City, Colorado. PlasmaCAM makes a cutting table, automation electronics, and software to control plasma cutters, and they interface their cutters to PCs using parallel ports. There are several reasons why parallel ports are [...]
read moreEngineered by LAVA
Each week at LAVA many ideas are generated in meetings, chance encounters in hallways, and in talks with customers and suppliers.Some thoughts presented here are completely raw, while others have percolated with us for some time. We call them “LAVA Engineered”. We’d like to share them with you in this blog. Some ideas will turn [...]
read moreCustomer Tools
|
|
|
|
|||
|
|
|