Client Profile: Digi International, Inc

Contact: Elizabeth Presson
elizabeth.presson@digi.com

Featured Product: The XBee product family (www.digi.com/xbee) is a series of modular products that make adding wireless technology easy and cost-effective. Whether you need a ZigBee module or a fast multipoint solution, 2.4 GHz or long-range 900 MHz—there’s an XBee to meet your specific requirements.

XBee Cloud Kit

Digi International XBee Cloud Kit

Product information: Digi now offers the XBee Wi-Fi Cloud Kit (www.digi.com/xbeewificloudkit) for those who want to try the XBee Wi-Fi (XB2B-WFUT-001) with seamless cloud connectivity. The Cloud Kit brings the Internet of Things (IoT) to the popular XBee platform. Built around Digi’s new XBee Wi-Fi
module, which fully integrates into the Device Cloud by Etherios, the kit is a simple way for anyone with an interest in M2M and the IoT to build a hardware prototype and integrate it into an Internet-based application. This kit is suitable for electronics engineers, software designers, educators, and innovators.

Exclusive Offer: The XBee Wi-Fi Cloud Kit includes an XBee Wi-Fi module; a development board with a variety of sensors and actuators; loose electronic prototyping parts to make circuits of your own; a free subscription to Device Cloud; fully customizable widgets to monitor and control connected devices; an open-source application that enables two-way communication and control with the development board over the Internet; and cables, accessories, and everything needed to connect to the web. The Cloud Kit costs $149.

I/O Raspberry Pi Expansion Card

The RIO is an I/O expansion card intended for use with the Raspberry Pi SBC. The card stacks on top of a Raspberry Pi to create a powerful embedded control and navigation computer in a small 20-mm × 65-mm × 85-mm footprint. The RIO is well suited for applications requiring real-world interfacing, such as robotics, industrial and home automation, and data acquisition and control.

RoboteqThe RIO adds 13 inputs that can be configured as digital inputs, 0-to-5-V analog inputs with 12-bit resolution, or pulse inputs capable of pulse width, duty cycle, or frequency capture. Eight digital outputs are provided to drive loads up to 1 A each at up to 24 V.
The RIO includes a 32-bit ARM Cortex M4 microcontroller that processes and buffers the I/O and creates a seamless communication with the Raspberry Pi. The RIO processor can be user-programmed with a simple BASIC-like programming language, enabling it to perform logic, conditioning, and other I/O processing in real time. On the Linux side, RIO comes with drivers and a function library to quickly configure and access the I/O and to exchange data with the Raspberry Pi.

The RIO features several communication interfaces, including an RS-232 serial port to connect to standard serial devices, a TTL serial port to connect to Arduino and other microcontrollers that aren’t equipped with a RS-232 transceiver, and a CAN bus interface.
The RIO is available in two versions. The RIO-BASIC costs $85 and the RIO-AHRS costs $175.

Roboteq, Inc.
www.roboteq.com

Client Profile: Pololu Robotics

Pololu Robotics
www.pololu.com
920 Pilot Road
Las Vegas, NV 89119

Contact: inbox@pololu.com

Pololu Robotics Zumo

Pololu Robotics Zumo

Embedded Products/Services: Pololu designs, manufactures, and distributes a variety of robotic and electronic parts. Get the building blocks for your next project at Pololu, where you can find wheels, motors, motion controllers, basic prototyping supplies, sensors, complete robot kits, and more. Pololu also offers a custom laser cutting service starting at $25.

Product information: The Pololu Zumo robot is an Arduino-controllable tracked robot platform that measures less than 10 cm × 10 cm, which is small enough to qualify for Mini Sumo. The Zumo includes two micro-metal gearmotors coupled to a pair of silicone tracks, a stainless steel bulldozer-style blade, six infrared reflectance sensors for line following or edge detection, a three-axis accelerometer and magnetometer, and a buzzer for simple sounds and music. A kit version is also available.

Exclusive offer: Use coupon code ZUMOCC20 for 20% off any one item in Pololu’s Zumo category (www.pololu.com/zumo).

PC-Programmable Temperature Controller

Oven Industries 5R7-388 temperature controller

Oven Industries 5R7-388 temperature controller

The 5R7-388 is a bidirectional temperature controller. It can be used in independent thermoelectric modules or in conjunction with auxiliary or supplemental resistive heaters for cooling and heating applications. The solid-state MOSFET output devices’ H-bridge configuration enables the bidirectional current flow through the thermoelectric modules.
The RoHS-compliant controller is PC programmable via an RS-232 communication port, so it can directly interface with a compatible PC. It features an easily accessible communications link that enables various operational mode configurations. The 5R7-388 can perform field-selectable parameters or data acquisition in a half duplex mode.

In accordance with RS-232 interface specifications, the controller accepts a communications cable length. Once the desired set parameters are established, the PC may be disconnected and the 5R7-388 becomes a unique, stand-alone controller. All parameter settings are retained in nonvolatile memory. The 5R7-388’s additional features include 36-VDC output using split supply, a PC-configurable alarm circuit, and P, I, D, or On/Off control.

Contact Oven Industries for pricing.

Oven Industries, Inc.
www.ovenind.com

G-Code CNC Router Controller

Sometimes, a single issue of Circuit Cellar isn’t enough.

Brian Millier, a retired instrumentation engineer in the Department of Chemistry at Dalhousie University in Halifax, Canada, needed more than one issue to explain his construction of a microcontroller-based, G-code controller for a CNC router. So we gave him room for a two-part series appearing in our April and May issues.

In Part 1, Millier explains the basics of G-code and how it is converted into three-axis motion, via the router’s three stepper motors. In Part 2, he describes his design of the router’s axis controller (powered by three small microcontrollers) and the host controller (powered by a more powerful microcontroller).

He calls the project one of the most challenging he has ever tackled.

So why bother? Especially when the combination of a PC and ArtSoft’s Mach3 software is a common and affordable approach to running a CNC router? Well, like most DIYers, Millier couldn’t resist an opportunity to learn.

“I want to be upfront and say that this is probably not the most practical project I have ever done,” Millier says in Part 1. “You can usually pick up a used PC for free, and the Mach3 software is professional-grade and handles much more complex G-code programs than my DIY controller will. However, it did provide me with a challenging programming task, and I learned a lot about designing a program with many concurrent tasks, all of which are quite time critical. Even if you are not interested in building such a controller, you may find interesting some of the techniques and tricks I used to provide the multi-axis stepper-motor motion.”

Millier’s two articles focus on the two main tasks of his project.

“The first was to understand the G-code language used to program CNC machines well enough to be able to write the firmware that would parse the G-code commands into something that a microcontroller could use to control the stepper motors used for each of the three axes,” he says. “The second task was to design the hardware/firmware that would actually control the three stepper motors, all of which had to move synchronously at accurate, ramped speeds.”

Millier wraps up his project by saying: “This was probably the most challenging project I’ve tackled, outside of work projects, in many years. In particular, the Basic program code for both of the controllers ran beyond 3,500 lines.”

If you are also someone who is willing to take on a tough task for the thrill of figuring it out yourself, check out Millier’s explanation of his project in the April and May issues of Circuit Cellar.