PJRC is Kickstartering two new models of its “Teensy” Arduino compatible, featuring a faster 180MHz Cortex-M4, more memory, more pins, and a second USB.

In the world of Arduino compatibles, you can choose from bare-bones clones or value-added innovators that develop new software as well as hardware, and occasionally risk some compatibility in order to advance the capabilities of the entire Arduino platform. In the latter category is Teensy, a DIY breadboard-oriented Arduino project from Portland, Oregon based PJRC, led by Teensy inventor Paul Stoffregen, known for its superior USB-based keyboard/mouse, LED array, and audio support. The eight-year old company has now upgraded the Teensy board with a much faster MCU, more RAM and flash, many more I/O pins, and additional USB and CAN ports, making it one of the fastest Arduino clones around.

Teensy 3.5/3.6
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The Teensy 3.5 and 3.6 Kickstarter campaign blasted past its modest, $5K goal to surpass $68K, with 19 days left. You can fund the boards for $23 and $28, respectively, with shipments due in October.

Both Teensy 3.5 and Teensy 3.6 feature faster NXP Kinetis Cortex-M4 chips. Teensy 3.5 moves up to a 120MHz MK64FX512VMD12, while Teensy 3.6 advances to a 180MHz MK66FX1M0VMD18 (PDF). This is compared to the 72MHz MK20DX256 on the Teensy 3.1 and 3.2, which is similarly a 32-bit Cortex-M4 MCU with a Floating Point Unit (FPU). Teensy 3.5 is further equipped with 192KB RAM and 512KB flash, while Teensy 3.6 increases it to 256KB and 1MB, four times the memory allotment on the 3.2 model. Both models also include a 4KB EEPROM.

Teensy 3.5/3.6 (upper) compared to earlier Teensy 3.2 (lower)
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Both new models add 28 new I/O pins for a total of 62 (42x breadboard friendly), compared to 34 on the earlier Teensy models. As a result, the new boards are almost twie as long as the pinout-compatible Teensy 3.1, growing from 37 x 18 x 4mm to 61 x 18 x 4mm.

The two boards differ further in that the Teensy 3.6 adds a high-speed, 480Mbps USB host port in addition to the existing full speed, 12Mbps USB port. The 3.6 model also has a second CAN Bus port, twice the general-purpose DMA channels at 32, and 11 touch-sensing inputs. The Teensy 3.5, however, has a trick of its own: 5V tolerance.

Teensy 3.5/3.6 pin assignments (left) and with breadboard and USB cable
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Common features include 25x analog inputs via a pair of 13-bit ADCs, 2x 12-bit analog outputs, and 20x PWM outputs. There’s a 100Mbps Ethernet MAC, with an optional Ethernet shield, plus a “native SD card port.”

Other features include 6x serial, 3x SPI, 4x I2C, and an I2S audio port with 4-channel digital I/O. You also get 14x timers, an RTC, a crypto unit, a CRC unit, and a random number generator.

Teensy 3.5/3.6 back side, showing surface mount pads
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A few of these I/O pins are located on surface mount pads on the back of the board, where they’re more difficult to access, but that’s still a lot of I/O firepower for such a small device. The October shipments will be accompanied by a “non-beta software release that provides compatibility with all the standard Arduino functions, libraries that come built-in to Arduino,” writes Stoffregen.


NXP Kinetis K66 MCU block diagram
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In a post at Hackaday, Brian Benchoff suggests that the Teensy 3.6’s 120MHz NXP Kinetis K66 chip is likely the most powerful MCU found on an Arduino board. However, Arduino Srl’s recently introduced STAR Otto board features a 180MHz Cortex-M4 based STM32F469BIT6 MCU with on-chip memories of 384KB SRAM and 2MB flash, supplemented externally by 16MB SDRAM and 128KB EEPROM, which may well outperform the Teensy 3.6 depending on the particular benchmark or application.

Speaking of applications, LED walls and audio have been two strengths of Teensy boards, thanks to earlier software libraries developed by PJRC’s Stoffregen, which have been upstreamed to the larger Arduino community. Both capabilities build on the board’s USB port. As Stoffregen describes in his brief history of Teensy on the Kickstarter page, Teensy 1.0 was one of the first Arduino compatibles with a USB port, and Teensy 2.0 stood out with its added support for USB keyboard, mouse, and MIDI capabilities.

 
Further information

The Teensy 3.5 and Teensy 3.6 boards are available on Kickstarter through Sep. 8 for $23 and $28, respectively, with shipments in October. Volume discounts are available. More information may be found at the Teensy 3.5/3.6 Kickstarter page, and more should eventually appear on the PJRC website.