Embedding touch tech in MCU firmware

Atmel’s comprehensive QTouch Library makes it simple for developers to embed capacitive-touch button, slider and wheel functionality into general-purpose AT91SAM and AVR microcontroller (MCU) applications.

To be sure, Atmel’s royalty-free QTouch Library offers several library files for each device, while supporting various numbers of touch channels – thereby enabling both flexibility and efficiency in touch apps. And by selecting the library file supporting the exact number of channels needed, devs can achieve a more compact and efficient code using less RAM.

Simply put, Atmel’s QTouch Library can be used to develop single-chip solutions for many control applications, or to reduce chip count in more complex applications. Meanwhile, the library offers devs the latitude to implement buttons sliders and wheels in a variety of combinations on a single interface.

There is also broad controller support for Atmel MCUs: AT91SAM, tinyAVR, megaAVR, XMEGA, UC3A and UC3B. Up to 64 sense channels are supported for maximum interface sensitivity ( 256-level sliders and wheels require only three channels), while the QTouch Library supports three patented capacitive touch acquisition methods: QTouch, QTouchADC and QMatrix.

In addition, Atmel Adjacent Key Suppression (AKS) technology enables unambiguous detection of button touches for maximum precision, with full debouncing reports for touch buttons helping to ensure single, clean contacts. And last, but certainly not least, a common API across all library versions simplifies development.

Interested in learning more? Additional information about Atmel’s QTouch library can be found here.

LIN networking for the automotive masses

LIN (Local Interconnect Network) is a serial network protocol used for communication between various vehicle components. The LIN Consortium was founded by five automakers (BMW, Volkswagen Audi Group, Volvo Cars, DaimlerChrysler) in the late 1990s, with the first fully implemented version of the new LIN specification (1.3) published in November 2002. Version 2.0 was introduced in September 2003, offering expanded capabilities and support for additional diagnostics features.

Specifically, low-cost local interconnect networking (LIN) systems are used throughout the automobile in comfort, powertrain, sensor and actuator applications. Vehicular LIN applications include roofs (sensors), steering wheels (cruise control, wiper, turning light, climate control, radio), seats (position motors, occupant sensors, control panels), engines (sensors), climate control (small motors, control panel) and doors (mirror, central ECU, mirror switch, window lift, seat control switch, door lock).

Atmel offers unique BCD-on-SOI technology for LIN, which combines high-voltage capability with the benefits of rugged SOI technology: high temperature resistance (T-junctions up to 200°C), optimized radiation hardness, very low leakage currents, low parasitics, high switching frequency and latch-up immunity.

“Our LIN devices operate in standard temperature environments to support roof, door, and car body sensors among others. They also perform flawlessly in very hot engine environments, up to 150°C/302°F ambient air temperatures,” an Atmel engineer told Bits & Pieces.

“The modular Atmel LIN family ranges from simple transceiver ICs to complex system basis chips with LIN transceiver and voltage regulator. At higher integration levels, our System-in-Package (SIP) solutions feature an Atmel AVR microcontroller, LIN transceiver, voltage regulator and watchdog in a single package.”

Interested in learning more about Atmel’s LIN solutions? Additional information is available here.

Atmel wants to listen to your car stereo

With over 30 years experience in designing broadcast radio platforms, Atmel is a supplier offering IC solutions with maximum performance, flexibility and integration level for the rapidly expanding AM/FM active antenna market.

In-depth know-how and high quality standards (ISO9001 and ISO16949) enable the specific quality and performance requirements of the car radio market.

Specifically, Atmel offers a lineup of highly integrated products with maximum quality level and excellent RF performance. This includes feature-rich and robust AM/FM antenna amplifier ICs boasting numerous advantages over discrete solutions. Indeed, Atmel’s technology can be used in any antenna, whether shark fin, short pole or glass/window antenna.

In addition, current-gen car stereos must be capable of playing digital music from players, memory cards, and Flash drives. And that is why Atmel AVR 32-bit microcontrollers are capable of powering a platform to access, decode, and play music files over  USB.

Various formats are supported, including MP3 and WMA (with AAC available soon), along with ID3 tags, playlist management, and more. As expected, Atmel also provides a complete software library, the AVR UC3 software framework, to help facilitate rapid and easy development.

Additional information about specific Atmel MCUs for car stereos can be found here.

Optimizing charge cycles and battery life

Bits & Pieces has been on a roll this week with an automotive theme in honor of the latest additions to Atmel’s touch family: the mXT336S and mXT224S. In this article, we’re going to take a closer look at how Atmel optimizes automotive charge cycles and battery life with its MCUs.

As automotive enthusiasts know, Li-ion technology is currently the first choice for modern high-performance batteries. To be sure, Li-ion batteries are up to 30 percent smaller and 50 percent lighter than conventional NiMH batteries – yet manage to store significantly more energy.

However, while the batteries do offer concrete advantages in terms of size, weight, recharge speed and resistance to memory effects, Li-ion has a higher cost compared to other battery types. Of course, this can definitely be improved by using a battery management system like Atmel’s which optimizes battery performance.

“Our Li-ion battery management solution offers high accuracy analog measurement functions in combination with efficient active cell balancing ensuring optimum usage of battery capacity,” an Atmel engineering rep told Bits & Pieces. “Specifically, the megaAVR, ATmega32HVE2 and ATmega64HVE2 microcontrollers (MCUs) can be used to improve the performance and longevity of 12V standard lead-acid batteries.”

As the engineering rep notes, the above-mentioned MCUs are designed for intelligent battery sensor applications – with the devices determining the state of charge and state of health for 12V standard lead-acid batteries by measuring the battery voltage, current and temperature.

“For cars with idle-stop-go function, this feature is mandatory to retain sufficient battery energy for a guaranteed engine start,” the engineering rep added. “Combined with the Atmel ATA6870 Li-ion battery monitor IC, it forms an ideal system solution for replacing 12V standard lead-acid batteries with Li-ion batteries.”

Additional key features of an Atmel-powered battery management system and components include:

• Active balancing – The industry’s first to feature active cell balancing for high cell count Li-ion batteries to prevent energy loss.
• Maximum safety – Highest accuracy due to simultaneous cell voltage measurement of the cells in the entire battery stack leading to precise state-of-charge and state-of health calculations.
• Smart sensing – Allows engineers to measure the battery voltage, current and temperature with up to 18-bit accuracy.
• Valuable development tools – PC-controlled development kits help devs easily build a battery management system and get the most of the battery management devices.

Interested in learning more? Detailed information about using Atmel’s powered system can be found here.

A closer look at Atmel’s vehicle portfolio

Earlier this morning, Atmel announced the expansion of an already formidable automotive maXTouch lineup with the mXT336S (optimized for 7-inch touchscreens) and mXT224S (targeted at smaller touchscreens and tablets).

In addition to touchscreens, Atmel boasts an extensive automotive ecosystem that meets strict quality demands, helping to make vehicles more safe and affordable. Primary solutions include battery management (Li-ion), car access, radio, networking, motor control systems and microcontrollers.

As previously discussed on Bits & Pieces, Atmel’s versatile AVR microcontrollers deliver power, performance and flexibility – making them appropriate for a wide range of automotive applications.

So what differentiates AVR microcontrollers from the competition in the automotive sphere? Well, according to an engineering rep, Atmel offers functionality and high temperature capabilities in its vehicle-oriented chip designs.

“Plus, complete system-in-package (SIP) solutions integrate components such as an AVR microcontroller, LIN and CAN interfaces, voltage regulator, watchdog, floating point unit (FPU), FlashVault code protection, high-speed Ethernet and USB with OTG connectivity in a single cost-effective package,” the engineering rep told Bits & Pieces. “In fact, Atmel’s highly integrated designs can reduce system costs by up to 60 percent, while saving time in development, integration and prototyping.”

Key specs include:

• High performance – Executing powerful instructions in a single clock cycle, Atmel’s 8-bit automotive AVR MCUs achieve throughputs approaching 1 MIPS per MHz, balancing power consumption with processing speed.
• Code protection – Atmel FlashVault allows devs to partially program and lock flash memory for secure on-chip storage. Code stored in FlashVault will execute as normal, but cannot be read, copied or debugged. It is also capable of carrying software such as math libraries or encryption algorithms to potentially untrustworthy environments where the rest of the source code can be developed and debugged.
• Built-in voltage protection – The on-chip voltage regulator with short-circuit monitoring interface featured in several 8-bit microcontrollers ensures reliable operation and extends the useful life of the device and the product it controls.
• Optimized power efficiency – Thanks to more than a decade of research, Atmel picoPower technology reduces microcontroller power usage in both sleep and active mode to achieve the industry’s lowest power consumption numbers.

Interested in learning more? Additional information about Atmel’s expansive automotive portfolio is available here and here.

Atmel expands maXTouch auto lineup

Atmel has rolled out a new maXTouch family to facilitate single-layer shieldless designs in automotive center stacks, navigation systems, radio interfaces and rear seat entertainment platforms.

“The mXT336S is optimized for 7-inch touchscreens, while the mXT224S targets smaller touchscreens and tablets,” said Stephan Thaler, Atmel Marketing Director for Automotive Touch Products. “Both are AEC-Q100-compliant and fully automotive qualified.”

Dedicated firmware and a high signal-to-noise ratio makes these devices ideally suited for very noisy environments. Since only a high signal-to-noise ratio enables detection of touches with a “gloved” finger, the devices provide full support for gloved hand operation on automotive touchscreens.

As Thaler notes, conventional touch controllers are unable to handle LCD noise, so an additional shield layer is typically required to prevent noise coupling.

“However, thanks to the [optimized] noise handling and filtering capabilities of our new automotive- qualified maXTouch devices, shields are no longer required, and designers can use single-layer sensors instead of dual or triple layers, which are typical in many current applications,” he explained.

“By eliminating an additional layer, designers have a thinner stack which reduces the overall system complexity, lowering the overall cost and power consumption, which results in higher yields during production.”

Indeed, the mXT336S/mXT224S devices support touch detection, up to 10 simultaneous touches, touch size reporting, single- and dual-touch gesture calculation, communication of X/Y positions, gesture support and the ability to eliminate unintended touches. Users can also perform multi-touch gestures (pinch, stretch, etc.), while unintended touches are rejected, such as a resting hand on the screen. Simply put, the above-mentioned key features help bring the smartphone experience into contemporary cars.

Samples of the automotive-qualified mXT336S and mXT224S touch controllers are currently available in TQFP64 packages, while demo kits for both devices can also be ordered to support design-in and shorten time-to-market.

Simplify Switch Application Design with LIN Bus Connections

By Daniel Yordanov and Berthold Gruber

Low-cost local interconnect networking (LIN) systems are typically used in comfort, powertrain, sensor and actuator automotive applications. As the number of applications and control switches to manage them has increased and the market for LIN systems has grown, so has the need for greater system efficiency, tighter integration and lower costs. In addition, applications for which the switches are located far from the control electronics and wires integrated into the wiring harness require high-voltage (HV) switches. Atmel supports these applications with a modular LIN family, including simple transceiver ICs, complex system basis chips (SBCs) and system-in-a-package (SiP) solutions. The Atmel® ATA6642 SiP device, in particular, was designed for complete LIN bus node applications.

The ATA6642 provides benefits for LIN applications such as the following:

• Switch control: Eight HV I/O ports allow flexible control of up to eight single switches, including flexible switch monitoring. Each input can be configured to trigger an interrupt upon state change, and if a state change is detected, an interrupt request is generated. If no wake-up occurs on a switch, the current source can be disabled in the serial peripheral interface (SPI) configuration register.
• Voltage measurement: The device’s HV I/O ports are each equipped with a voltage divider. The VDIV pin guarantees a voltage- and temperature-stable output ratio for the selected input.
• Pulse-width-modulated (PWM) load control: The device’s switch interface current sources can directly control PWM loads, such as switch scanning and LED driving. A universal serial interface (USI) helps enable significantly higher transfer rates and uses less code space than solely software-based solutions. Interrupts are included to reduce the processor load.
• RGB LED control: With its constant current sources, the device is well suited for LED control systems: for example, to control an RGB LED.
• H-bridge relay control: The device can be used as a relay driver: for example, in a window lifter system. If the output current of each I/O port is not sufficient to drive the load, the output pins can be interconnected to achieve a higher load current.

For diagrams and more details about the Atmel ATA6642 and its use in LIN applications, see the article “Simplifying the Design of Switch Applications with LIN Bus Connections.”

Easing Design Process with AUTOSAR Standard Support

By Eric Tinlot

Today’s vehicles have up to 70 electronic control units (ECUs) supporting many of their in-vehicle functionalities—a result of tougher constraints in areas including security, environment, comfort and safety. All of these functionalities call for simultaneous interactions by sensors, actuators and control units. But with the complexity of signal interactions among ECUs, this can be a challenging prospect. What’s more, these complex interactions and the increasing number of ECU nodes are increasing the amount and complexity of software required.

The Automotive Software Platform and Architecture (AUTOSAR) is an open and standardized automotive software platform and architecture jointly developed by automotive manufacturers, suppliers and tools developers. Because it provides an abstraction layer between hardware and application, the standard allows hardware-independent development and testing of the application software.

Atmel has worked with Vector Informatik to fully support the Atmel 32-bit AVR automotive family devices in AUTOSAR through the MICROSAR bundle from Vector. We have developed a microcontroller abstraction layer (MCAL) for our automotive-qualified AVR devices. These MCAL modules and Vector’s LIN/CAN communication layers are integrated into Vector’s complete MICROSAR environment. This AUTOSAR bundle for the 32-bit AVR family is available from Vector.

The AUTOSAR bundle consists of a microcontroller abstraction layer for AVR automotive-qualified MCUs and Vector Informatik’s LIN/CAN communication layers.

To learn more, including which MCALs we’ve developed, read the full article, Atmel Eases Automotive Design Process Through Support of AUTOSAR Standard.

New Devices for Automotive Switch Scan Apps

Atmel has a new ultra-small, low-power LIN family for automotive switch scan applications and in-vehicle ambient light control. At only 5x5mm and 7x7mm, the ATA664151 and ATA664251 include a wide range of on-chip functionalities, so you can save the costs of otherwise using multiple chips. Some device highlights:

• Eight-channel high-voltage switch interface with current sources and analog voltage multiplexer
• Integrated state change detector for switch scan apps with extremely low current consumption
• Three independent PWM signals
• LIN 2.2 and SAEJ2602-2-compliant transceiver

Get more device details here.