Archive for the ‘Hardware’ Category:
FTDI Serial Adapter as a Simple Digital Interface
I’ve had the good fortune to be accepted as an occasional contributor to the Hack a Day blog. (Hack being slang for an informal method of engineering, not criminal acts!)
My first substantive tutorial for the site describes the use of FTDI Bitbang Mode, a method of using a common, inexpensive USB-to-serial adapter as a quick & dirty GPIO interface. This facilitates the sort of prototyping typically done using microcontrollers, but in the comfortable and unconstrained development environment of mainstream PCs. The technique is particularly well-suited to SPI-type protocols; I’ve had this communicating with shift registers, LED driver chips and even video overlay ICs, as well as reading various optical rotary and linear encoders.
You can read the full article over at hackaday.com.
Tags: adapter, bit bang, bitbang, ftdi, hack, hackaday, hacking, interfacing, protocol, serial, spi, usb
Hacking the Microchip Explorer 16 Development Board
Disclaimer and caution: some of the changes outlined in this article involve soldering and modifications to a fairly costly circuit board, which always runs some small risk of damage or mayhem. While I suspect that most anyone with the inclination to buy and use one of these boards is well-versed in soldering and related precautions, maybe that’s not actually the case, and I assume no liability for any damage that might occur to the board, yourself or your belongings.
The Explorer 16 Development Board is Microchip’s mainline trainer/project board for 16-bit (and lately now, 32-bit) microcontrollers. The modular design of this board allows use of three different microcontroller families along with add-ons for networking, storage, audio, LCD graphics and more, and providing a common point of reference that allows Microchip to provide working example software templates for these different types of projects.
For all its virtues, this is not to say the experience can’t be improved. What follows are a few simple tidbits I’ve learned for enhancing the functionality of this kit.
The 25¢ I2C Adapter
This project demonstrates a novel repurposing of the existing display control lines present on many graphics cards as an inexpensive method of interfacing computers with a variety of sensors and devices.
I2C (Inter-Integrated Circuit) is a two-wire serial bus typically used inside computers for low-level communication between components, but it’s also seen in robotics and hobbyist electronics for interfacing all manner of sensors, displays and actuators. I2C connections are often readily available on microcontrollers and esoteric embedded systems, but there’s traditionally little call for end-user access to this bus on mainstream personal computers. Lately though, netbooks and other small form-factor systems are increasingly being put to use as the high-powered “brains” of many homebrew projects. To sense and react in the physical world, a USB to I2C adapter (or “bridge”) device is typically used, often at considerable expense.