Tag Archives: ATxmega256A3BU

Up close and personal with Atmel’s XMEGA-A3BU Xplained

Atmel’s ATxmega256A3BU is a low power, high performance 8/16-bit AVR microcontroller featuring 256KB self-programming flash program memory, 8KB boot code section, 16KB SRAM, 4096-byte EEPROM, four-channel DMA controller and an 8-channel event system.


It is also equipped with dual 12-bit ADC, two 12-bit DAC channels, four analog comparators, AES and DES crypto engines, 7 16-bit timer/counters, 6 USART, two SPI, two TWIs and an RTC battery backup system.

“The ATxmega256A3BU can be used to power a wide range of applications,” an Atmel engineering rep told Bits & Pieces. “Specific examples include building, industrial, motor, board, and climate control, hand-held battery applications, factory automation, power tools, HVAC, networking, metering, large home appliances and optical/medical devices.”

To accelerate development with the ATxmega256A3BU microcontroller (MCU), Atmel offers the XMEGA-A3BU Xplained, a hardware-based platform that helps engineers evaluate the device and seamlessly integrate AVR XMEGA architecture into a wide range of designs.

In addition to the ATxmega256A3BU microcontroller (MCU), key XMEGA-A3BU Xplained features and capabilities include:

  • Keep RTC running in the backup system while main power is absent
  • Display data on the 128×32 pixels of the FSTN LCD display
  • Read temperature sensor with the ADC
  • Read light sensor with the ADC
  • Use the Atmel QTouch library to detect touches on the touch button
  • Read/write data to the 64Mbit Atmel DataFlash
  • 3 push buttons to interact with the microcontroller
  • 4 LEDs to show status information
  • Program the kit via USB bootloader or an Atmel programmer
  • Expand the board with Xplained top modules

The XMEGA-A3BU Xplained can be purchased from Atmel’s official store here.

Designing an advanced glucose meter with AVR MCUs

A glucose meter can best be described as a portable battery powered medical device used to measure blood glucose concentration on test strips.


Glucose meters are typically equipped with a display and mass storage solution, with certain models featuring an IrDA or a USB interface to export data to a computer. Unsurprisingly, there is currently an emerging trend for glucose meters to be equipped with Bluetooth or BTLE capabilities, thereby facilitating easy connection to mobile devices such as smartphones and tablets.

Key design considerations for a glucose meter include ultra low power consumption, high system integration (high-end analog peripherals), low BOM cost and versatile connectivity options for bio-sensors, display, buzzer, memory and PCs.

As illustrated in the diagram above, Atmel’s versatile AVR portfolio can be used to help engineers design an advanced glucose meter using the ATxmega256A3BU 8/16bit low power AVR-based MCU, AT86RF231/232/233 RF Transceiver, AT42QT Touch IC and ATSHA204 Authentication IC with EEPROM.

“Simply put, Atmel’s ATxmega256A3BU¬†offers ultra low power consumption, high integration, compact package and connectivity features to address the key needs of a glucose meter,” an Atmel engineering rep told Bits & Pieces.

“In terms of ultra low power requirements, our ATxmega256A3BU¬†supports 1.62-3.6V and boasts 5 flexible sleep modes. In Power Save mode (RTC running), the current consumption is below 1uA, while in Active Mode, the current consumption is 350uA/MHz at 1.8V. Meanwhile, a DMA Controller handles data transfer between the peripherals and memory.”

On the connectivity side, Atmel offers a full speed compliant USB device port with embedded PHY to save BOM cost (~$0.5-$1.0). As expected, the port can be used for battery charging and data transfer to a PC. Atmel also offers integrated UART, USART, SPI and I2C – allowing easy connection to external sensors, memories and display.

“It should also be noted that Atmel-powered glucose meters require a minimum in terms of external (additional) hardware, thanks to integrated RTC, high performance ADC and DAC, PLL and voltage reference,” said the engineering rep.

“And last, but certainly not least, Atmel’s AVR MCUs benefit from our extensive software ecosystem, such as Atmel Studio and free software libraries of production ready source code including ZigBee PRO Software (BitCloud), Proprietary Low Footprint, 802.15.4 Mesh Software Stack, USB Stack and QTouch Library.”