Back at Maker Faire Bay Area in May, the iFixit team took a deeper dive into the technology that is powering some of today’s sports watches, like the TomTom Runner. During its teardown, the iFixit team revealed that the wearable device was powered by an Atmel ATSAM4S8C.
The popular GPS sports watch is equipped with a built-in heart rate monitor, a large monochrome LCD display and one-button control. In addition, the TomTom Runner is embedded with an accelerometer and sensors allowing it to work both outdoors, indoors and even on a treadmill, thus providing providing a user with the kind of data they’d expect to find on most sports watches — such as distance, pace, stride length, calories burned and lap times all in real-time. Bluetooth Smart support also enables a user to sync the Runner with other devices, including a heart rate strap.
Based on ARM’s powerful Cortex-M4 core, the Atmel | SMART SAM4S lineup offers increased performance and power efficiency, higher memory densities (up to 2MB of Flash and 160KB of SRAM), along with an extensive peripheral set for connectivity, system control and analog interfacing. The SAM4S operates at 120MHz and integrates Atmel’s Flash read accelerator, along with optional cache memory to increase system performance. The SAM4S also features a multi-layer bus matrix, multi-channel direct memory access (DMA) and distributed memory to support high data rate communication.
So, how low is low in terms of power consumption? Well, the Atmel | SMART SAM4S family manages to achieve 200µA/MHz in dynamic mode at a low operating frequency; 30mA at 120MHz; and 1µA at 1.8V in back-up mode with the real-time clock (RTC) running. In short, it offers some of the best power consumption/performance rates on the market for standby mode, achieving 120MHz+ operating frequency with a RAM retention mode below 25µA.
On the security side, the SAM4S prevents unauthorized access to on-chip memory, supports secure device reconditioning (chip erase) for reprogramming – while a 128-bit ID and scrambled external bus interface ensures software confidentiality as the hardware cyclic redundancy check (CRC) checks memory integrity. And last, but certainly not least, fitting a device with a SAM4S means easy access to Atmel Studio 6, which offers hundreds of ARM project examples with source code to streamline the design process.
Joining a number of other watchmakers, TomTom Runner is the latest device to feature an Atmel | SMART SAM4S microcontroller. If you recall, Secret Labs announced last year that their AGENT smartwatch was powered by both the SAM4S and tinyAVR microcontrollers.
For those interested in learning more, Atmel engineers have recently published 28 application notes for the company’s comprehensive Atmel | SMART SAM4S devices.