Rabid Prototypes shipped a tiny Arduino Zero clone called the “Tau,” and launched an expanded Zero-like “Firecricket” for light, sound, and motion control.

Early this year, before Boston-based Rabid Prototypes launched its second-generation, 36 x 18mm Neutrino 2.0 Arduino Zero clone on Kickstarter, it mounted a KS project for a smaller, 28 x 15mm “Tau” clone of the Arduino Zero. Due to ship in May, the Tau was delayed throughout the summer, but is finally shipping to backers. It’s also available for order to newcomers for $15, which is $5 more than the KS price. The original Neutrino 1.0 is once again back in stock, as well.

Left to right (to scale): Tau, Neutrino, Firecricket
(click images to enlarge)

Now Rabid Prototypes has introduced a Firecricket board — an Arduino compatible that features light, sound, and motion controllers for animating replica props for cosplayer and Halloween costumes, or adding sound, light, or movement to toys and other objects. There are six days left to go at Kickstarter to buy into the successfully funded, $27 Firecricket, which is due to ship in November. Like the Zero, Neutrinos, and Tau, the board has an Arduino compatible, Atmel ATSAMD21, a 48MHz Cortex M0+ MCU.

Here we’ll take a look at the Firecricket, followed by a brief examination of the Tau. As for the Neutrino 2.0, it’s unclear if it will make its September deadline. A September 9 post said the macrofab had finished assembling the boards and had begun programming and testing them. The update also said backers had to fill out a survey that would be sent soon “or your shipment may be delayed!”

 
Firecricket

Measuring 42 x 25mm, the Firecricket is larger than Rabid Prototypes’s Neutrino 2.0 boards and much larger than the Tau, but this is more than just an oversized Zero clone. The Firecricket lets you animate costumes and any other object with light, sound, and motion. Designed primarily for cosplayers or Halloween enthusiasts looking to kick up a costume or doorway display, the Firecricket can also be used to add voices, sound effects, lighting, or movement to stuffed animals, drawers, doorways, and more.

Firecricket from both sides (left) and integrated in breadboard with various servos, LEDs, and speakers
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The Firecricket features an N-MOSFET with a flyback diode circuit for driving high current inductive loads, such as vibration motors or 3W LEDs, thereby letting you control light, sound, and motion effects. There’s also a 2.5W audio amplifier, plus a microSD slot for storing sound effects, bitmaps, and configuration files.

The Firecricket runs on an Atmel ATSAMD21E17A, the same MCU used on the Tau. Like the ATSAMD21G18 on the Neutrino boards and the Arduino Zero, this is a 48MHz, 32-bit Cortex M0+ device, but it has half the RAM and flash at 16KB and 128KB, respectively. It also has fewer SERCOMs and ADC channels, and fewer pins, with 32.

Firecricket detail view
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The Firecricket integrates 12x digital pins, including 10x PWM channels and 2x dedicated I2C pins with pullups. The Firecricket is further equipped with 3x 12-bit ADC channels and a single 10-bit DAC. The board has a 2.5W amplifier, and a voltage regulator with 3.5V – 5.5V input and 3.3V, 300mA output. You can power up via the onboard micro-USB port or with batteries.

If you’re concerned that the Firecricket might be delayed as long as the Tau was, you can take heart in Rabid Prototypes’s claim that “a prototype of the Firecricket has already been assembled and tested.” A lengthy video demo shows the board controlling a variety of speakers, buzzer, servos, and more.

The Kickstarter page details all pin assignments, and includes a sample Arduino IDE sketch that duplicates the video demo’s functions. Unlike with the Neutrino or Tau, however, there are no open source claims.

 
Tau

The Tau shrinks the guts of the Arduino Zero to a miniscule 28 x 15mm footprint, and has a much lower price. Like the Firecricket, the Tau uses the Atmel ATSAMD21E17A, which is clocked at the same 48MHz rate as the ATSAMD21G18 on the Neutrino boards and the Zero. However, the chip has only 16KB RAM and 128KB flash instead of 32KB and 256KB, among other differences listed above. As Rabid Prototypes notes, however, this is “far more powerful than your standard Arduino.”

Tau from both sides
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Now shipping to Kickstarter backers, the open source Tau is available for $15 instead of almost $50 for the Arduino Zero or $20 for the Neutrino 2.0. Unlike the Neutrino 2.0, the Tau cannot function as a USB host, and it lacks an SPI header, although SPI is still supported on pins 10-13.


Tau detail view
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Like the Firecricket, the Tau has 12x digital pins, including 10x PWM channels and 2x dedicated I2C pins with pullups. The Tau is also similarly equipped with 3x 12-bit ADC channels and a single 10-bit DAC, and has a similar power profile, as well as a micro-USB port to power it. A few LEDs are available as well.

 
Further information

The Firecricket is available on Kickstarter through Sep. 27 for $27, with volume discount packages also available. The board is scheduled to ship in November. More information is available on the Firecricket Kickstarter page.

The Tau is now shipping to Kickstarter backers in the U.S., with customers in other countries due to receive their boards in the coming weeks. New orders for $15 will also likely be fulfilled in the coming weeks. More information may be found at the Tau product page at the Rabid Prototypes website, as well as at the now completed Kickstarter project page.