Tag Archives: SPI

WifiDuino for the Internet of Things

Powered by Atmel’s versatile ATmega32U4 microcontroller (MCU), the open source WiFiDuino is a chip-sized development board that packs a 28×64 OLED display.

“We designed WifiDuino based on our belief in the future of the Internet of Things (IoT) when everything is connected. We will be living in a world when every object can communicate with each other using WiFi,” a WiFiDuino rep explained in a recent Indiegogo post.

“With WifiDuino, you no longer need to worry about getting a WiFi shield. [We] have done the hard part for you. It’s great for people who are tired of buying WiFi shields every time you want the board to be connected.”

Aside from Atmel’s ATmega32U4 MCU, key WiFIDuino specs and features include:

  • Supports Arduino IDE (Leonardo)
  • STA, AP, ADHOC network modes
  • Connects directly with smartphone
  • 20 digit I/O
  • 12 Analog I/O
  • UART, I2C, SPI
  • 5v power and I/O pin level

Interested in learning more? You can check out the project’s Indiegogo page here.

Who’s talking about the Arduino Zero ?

The Atmel-powered Arduino Zero dev board was officially announced on May 15th, 2014. The board’s debut has already been covered by a number of prominent tech publications, including Ars Technica, HackADay, EE Times, Electronics Weekly, CNX SoftwareUberGizmoGeeky Gadgets, SlashGear, PC World, SemiWiki and Makezine.

Sean Gallagher, Ars Technica

“The Zero is a 32-bit extension of Arduino’s flagship Uno board, developed jointly by the Arduino team and Atmel, targeted at helping developers prototype smart devices. Based on the Atmel SAM D21 ARM Cortex-based microcontroller, the Zero includes Amtel’s Embedded Debugger—allowing developers to debug their projects without having to wire up another interface.


“It gives developers a huge boost in storage and memory over the Uno, providing 256KB of onboard Flash storage (compared to the Uno’s 32KB) and 32KB of static RAM (compared to the Uno’s 2KB). It can also emulate an Electronically Erasable Programmable Read-Only Memory (EEPROM) of up to 168KB, while the Uno only supported 1KB of EEPROM.”

Brian Benchoff, HackADay

“The Arduino Zero uses an Atmel ARM Cortex-M0+ for 256kB of Flash and 32k of RAM. The board supports Atmel’s Embedded Debugger, finally giving the smaller Arduino boards debugging support.

“The chip powering the Zero features six communications modules, configurable as a UART, I2C, or SPI. USB device and host are also implemented on the chip [and] there are two USB connectors on the board.”

Max Maxfield, EE Times

“I’ve become a huge supporter of the Arduino, from the concept to the hardware to the software (IDE) to the ecosystem. I’m now using Arduinos and Arduino-compatible platforms for all sorts of projects, including my Infinity Mirror, my Inamorata Prognostication Engine and my BADASS Display.

“Each Arduino and Arduino-compatible platform offers different features, functions, capacities, and capabilities, which makes it possible to select the optimal platform for the project at hand using criteria such as size, cost, performance, and number of input/output pins. As of this morning, there’s a new kid on the block – the Arduino Zero, which has been jointly developed by Atmel and Arduino.”

Alasdair Allan, MakeZine

“While it shares the same form factor as the Arduino Leonardo—with 14 digital and 5 analog pins—all of the digital pins except the Rx/Tx pins can act as PWM pins, and the analog pins have a 12-bit ADC instead of the Leonardo’s 10-bit ADC, giving significantly better analog resolution,” writes Makezine’s Alasdair Allan.

“The new board comes with 256KB of Flash memory, and 32KB of SRAM. While the new board doesn’t have EEPROM, it does support 16KB by emulation, so Arduino sketches relying on this feature will still run without issue.”

Arduino Zero – official specs:

  • Microcontroller ATSAMD21G18, 48pins LQFP
  • Operating voltage 3.3V
  • Digital I/O Pins 14, with 12 PWM and UART
  • Analog input pins 6, including 5 12bits ADC channels and one 10 bits DAC
  • DC current per I/O Pin 7 mA
  • Flash memory 256 KB
  • SRAM 32 KB
  • EEPROM up to 16KB by emulation
  • Clock speed 48 MHz

Interested in learning more? You can check out the official Arduino Zero page here.

Atmel’s ATtiny85 MCU powers ButtonDuino dev board

ButtonDuino – which recently made its Indiegogo debut – is an uber-mini (0.73in x 0.718in), USB programmable development platform powered by Atmel’s popular ATtiny85 microcontroller (MCU).

The open source ButtonDuino is breadboard compatible, so it plugs, with no pin conflict, directly into any standard pitch (2.54mm) breadboard as well as vero-boards. In addition, the platform can also be easily stacked with any ButtonDuino compatible ButtonShields and is expandable via I2C or SPI.

Upcoming ButtonShields include:

  • Real time clock (RTC)  – I2C
  • EEPROM – I2C
  • Temperature sensor  – I2C
  • Pressure resistive sensor
  • Coin battery pack
  • 3-axis digital compass

“[Users can] create amazing Graphical User Interfaces (GUI) with LabVIEW by National Instruments. All you need is the same micro-USB cable that you already have to program and power ButtonDuino,” the ButtonDuino crew explained.

“The best feature? ButtonDuino’s schematics, code and bootloaders are all free and open source. All the details will be released once the product is finalized.”

Aside from Atmel’s popular ATtiny85 microcontroller (MCU), key ButtonDuino components include:

  • USB Regulated power up to 800mA via external power supply or 500mA from PC/laptop
  • Programmable via USB or AVR mkII
  • Arduino IDE 1.0+ (Windows/OSX/Linux)
  • 6 x available I/O Pins and I2C and SPI expandable
  • 8k flash memory without bootloader (6k after USB bootloader)
  • 3 x 8 bit hardware PWM pins
  • 4 x 10 bit ADC pins
  • Power LED
  • Test LED (Pin 1)
  • Soon to be available in deep red (PCB silkscreen)

Interested in learning more?

You can check out ButtonDuino’s official Indiegogo page here.

Atmel debuts new Smart RF Receiver IC lineup

Atmel has launched a new family of low-power, high-performance RF receivers designed specifically for the automotive and smart RF markets.


“With the industry’s lowest power consumption, high sensitivity and excellent out-of-band blocking performance, the three new devices (ATA5781, ATA5782 and ATA5783) are ideal for automotive applications including remote keyless entry (RKE), passive entry go (PEG) / passive entry, passive start (PEPS), remote start (RS) and tire pressure monitoring (TPMS) systems,” an Atmel engineering rep told Bits & Pieces.

“This new RF family is also a perfect fit for a broad range of smart RF applications including remote control systems such as garage door openers or telemetering applications. Indeed, the ATA5781ATA5782 and ATA5783 family consumes only 9.8mA in receive mode, whereas the power consumption of competing devices is typically 12mA.”

Simply put, the reduced drain leaves more charge in the battery, leading to longer standby times when the car is stopped with the receiver enabled. The parts feature an excellent sensitivity of -122.5dBm (typical) when programming the IFBW (intermediate frequency bandwidth) to its lowest value of 25kHz. This RF blocking performance rates the receiver’s immunity to disturbers which are frequently present in the field.

“The outstanding blocking performance of the ATA578x family significantly reduces power-robbing false wake-ups. It also prevents RF range reduction and communication failure caused by RF disturbers,” the engineering rep continued. “Plus, the new devices provide dual paths for simultaneous FSK and ASK reception, as well as superior flexibility by combining RF functionality, an advanced state machine and an Atmel AVR microcontroller core.”

In addition, customers can configure up to five services including RKE, RS, PEPS and TPMS on the fly in idle mode via SPI (serial peripheral interface). This makes end-of-line programming at the customer production site unnecessary, helping to save production time and cost. Meanwhile, dual path reception and flexibility allow customers to adapt receiver behavior for individual applications.

Customers can also optimize power consumption with an adaptable polling scheme. If customer-specific adaptations are required, designers can simply add the existing firmware via Flash (ATA5782) or user ROM (ATA5783).

As noted above, the new RF receiver family includes:

  • ATA5781: Ready-to-use RF receiver IC with integrated firmware.
  • ATA5782: Firmware is included in read-only memory (ROM). Additional Flash option for application-specific software requirements.
  • ATA5783: Cost-optimized version of ATA5782, where customer software is ROM masked.

It should be noted that Atmel’s RF portfolio includes receiver and transceiver devices (ATA5831/32/33) which are pin-function- and RF-matching-compatible to ensure maximum development re-use for one- and two-way systems – thereby helping to accelerate development. Last, but certainly not least, end-application engineers can use the same printed circuit board design for uni-directional and bi-directional car access systems.

Capacity and performance characterize Atmel’s megaAVR

Our ongoing coverage of Atmel’s comprehensive AVR portfolio has taken readers on a detailed MCU (microcontroller) tour this month. First, Bits & Pieces dove into the guts of Atmel’s AVR UC3 which is built around high-performance 32-bit AVR architecture and optimized for highly integrated applications.

We then spent some time with Atmel’s AVR XMEGA, an MCU designed for real-time performance, high integration and ultra-low power. And today we want to properly acquaint our readers with Atmel’s megaAVR microcontroller, which is well known for both capacity and performance.

“When your designs need some extra muscle, you need the megaAVR. Ideal for applications requiring large amounts of code, the megaAVR offers substantial program and data memories with performance up to 20 MIPS, with picoPower technology minimizing power consumption,” an Atmel engineering rep told Bits & Pieces. “All megaAVRs offer self-programmability for fast, secure, cost-effective in-circuit upgrades. You can even upgrade the flash while running your application.”

Indeed, the megaAVR family offers Atmel’s widest selection of devices in terms of memories, pin counts and peripherals. Meaning, engineers can choose from general-purpose devices to models with specialized peripherals like USB, or LCD controllers, or CAN, LIN and Power Stage Controllers.

More specifically, Atmel’s megaAVR family is equipped with on-chip flash, SRAM, internal EEPROM, SPI, TWI, USART, USB, CAN, LIN, watchdog timer, a choice of internal or external precision oscillator and general purpose I/O pins.

In terms of analog functions, the megaAVR boasts advanced analog capabilities, such as ADC, DAC, built-in temperature sensor and internal voltage reference, brown out detector, a fast analog comparator and a programmable analog gain amplifier. Simply put, the high level of integration allows designs with fewer external analog components.

And last, but certainly not least, megaAVR microcontrollers help accelerate the development process with advanced in-system programming and on-chip debug, while in-system programming works to simplify production line programming and field upgrades.

Interested in learning more? A full breakdown of our AVR portfolio is available here.

ATmega32 in your home-built DNA sequencer

The May 2013 issue of Circuit Cellar magazine has a great article by Fergus Dixon, who uses an Atmel ATmega32 microcontroller to operate a DNA sequencer.

One of the dozen ways to sequence DNA is to apply a reagent to the DNA sample. If the reagent reacts with the base pair on the end of the DNA strand it splits the pair and emits a tiny burst of light. If it is a double pair the burst of light is twice as strong. Then you just work your way up the DNA strand “zipper,” breaking the pairs and recording which of the 4 pairs you just broke. Now you understand why it took years to sequence even a short DNA strand.


Here is a control board from a DNA sequencer designed by Fergus Dixon

Fergus had the usual engineering fun you might expect when doing something this cool. The flat-black box he housed the light sensor in had a tiny hole. Light variance in the room showed up as noise. He had to figure out a method to drive stepper motors so they were smooth and got to 3000 RPM. He designed reagent solenoid injector drivers that worked off of 100V pulses, while also fiddling with the SPI ports. My consultant buddy John Haggis swears that any serial interface will take up 6-person months of labor.

I used to laugh at that – but I now think he is right. You have to get the hardware working, develop protocols, test for exception conditions – yeah, I can see six months just getting two devices to talk to each other.

You can see that Circuit Cellar has some great articles. The same May 2013 issue has an article on a wi-fi connected energy monitor, a serial port to SPI programmer, a G-code CNC router, a MIDI communication device, and a reprint of a radiation monitor – like a Geiger counter.

Now I can’t show you these articles on-line, since Circuit Cellar is a print magazine. And you have to give them 50 bucks a year to get it. You can get it as a digital pdf if you want to save trees. Its $85 a year for the both print and digital versions. There are large discounts for two- or three-year subscriptions. Best of all, you can give them something like $225 and get every single issue in history on a thumb drive. Then with your combo subscription you can add your monthly pdf to the archive thumb drive, and still have the print edition to impress your friends and boss.