Designing industrial sensors with Atmel AVR: Part 2

Yesterday, Bits & Pieces took a closer look at how Atmel’s versatile AVR portfolio can be used to power industrial sensors which are typically tasked with detecting, positioning or identifying an object or rotating axis in a factory-automated system.

And today we will discuss an Atmel-powered sensor reference design, or more specifically, the HMT7442 IO-link transceiver and optimized IO-Link device MESCO software stack – courtesy of Atmel, HMT and MESCO Engineering.

“IO-Link is the emerging industrial communication standard to connect the control unit to sensors and actuators. The standard is backwards compatible with the commonly used binary switch signaling and introduces a bi-directional digital communication. These capabilities bring several benefits to the end user, including easier cabling, remote diagnostics and configuration,” an Atmel engineering rep told Bits & Pieces.

“For many sensor designers, the physical size constraint is the key factor for integrating the IO-Link capability. And that is why Atmel, HMT and MESCO Engineering have placed a strong focus on saving board space in our offering of the TM96.0 GENIE Explorer Variant A reference design.”

More specifically, the TM96.0-A reference design demonstrates the high integration of the Atmel, HMT and MESCO solution. It acts as an IO-Link device and is equipped with a push button, two LEDs and a potentiometer to allow developers to add stimuli to the system.

“The reference design runs the MESCO IO-Link stack on an Atmel tinyAVR88 microcontroller and communicates on the IO-Link cable using HMT’s HMT7742 PHY IC,” the engineering rep continued.

“The implementation used in the reference design does not require external protection to sustain reverse polarity or to comply to the EMC surge protection defined in the IEC 60255-5 standard. This makes the TM96.0 an ideal tool to evaluate the Atmel-HMT-Mesco solution.”

Meanwhile, the TM96.0-B Evaluation Kit enables hardware and software designers to develop, test and debug the IO-link sensor application. Basically, the TM96.0B features the IO-link transceiver HMT7742 and the Atmel ATmega328P. It is equipped with all necessary connectors for in-system programming, while supporting debug sessions using Atmel’s free AVR StudioIDE, Atmel AVR Dragon or Atmel JTAGICE-mkII. Plus, an evaluation kit is provided with pre-compiled MESCO library software, which can be linked to the main application using the WinAVR GCC compiler.

Interested in learning more about how Atmel AVR MCUs can power your industrial sensors? Be sure to check out our detailed device breakdown here.

Designing industrial sensors with Atmel AVR: Part I

Industrial sensors are typically tasked with detecting, positioning or identifying an object or rotating axis in a factory-automated system. Industrial sensors utilize a variety of technologies, including inductive, magneto-resistive, capacitive, optical, pressure and ultrasonic.

Key design considerations include:

• Non-volatile storage for calibration values
• Small PCB size
• Accurate analog measurement
• Arithmetic for signal conditioning
• Digital communication interface for new emerging standards such as IO-Link
• Optional analog output signal
• Long product life time
• Optional hardware authentication products for secure identification and authenticated confidential communications

“Atmel’s versatile AVR family of microcontrollers enables designers to meet the needs of a variety of sensor applications. First off, there is the small form factor, down to DNF 2x2x0,5 mm. We also provide on-chip true EEPROM, ADC with differential measurement/optional gain stage and internal analog reference voltage remains stable in changing temperatures,” an Atmel engineering rep told Bits & Pieces.

“Meanwhile, efficient 8-/16-bit CPU minimizes power consumption. Additional key specs include serial communication interfaces with Direct Memory Access (DMA) support, internal digital-to-analog converter (DAC), pulse width modulation (PWM) and CryptoAuthentication support, the latter offering a secure vault for root secrets (keys) and secure mechanisms for authentication.”

Interested in learning more about designing industrial sensors with Atmel AVR? You can check out our extensive device breakdown here. Also, be sure to check back tomorrow for part two of this series for an in-depth look at an Atmel-powered sensor device reference design.