Amazon Halo Teardown

2022-01-19 | By bekathwia

License: None

I wore the Amazon Halo Band for a few weeks to try it out before I took it apart to see what’s inside. This thing’s got sensors for movement, heart rate, and pulse oximetry, as well as the microphones necessary to clearly record your speech. The packaging is mostly recyclable, except for a few plastic bits. It comes with a USB charging clip.

Tools used in this teardown:

Tweezers
Flush snips

Parts we could identify (some with the help of txyinfo on Hackaday.io):

2x Analog MEMS Microphone - DB Unlimited MM034202-8
2x i2c temperature sensor - asm Osram as6200
RGB LED
i2c LED Driver - Texas Instruments LP5562
2x Photodiode - Vishay Semiconductors VEMD8080 or VEMD8081
Multi-LED - asm Osram SFH 7016
High luminous intensity Green LED - asm Osram CT DBLP31.12
6-Axis IMU - TDK InvenSenseICM-20600
Battery charger - Texas Instruments BQ25125
Serial NOR Flash Memory 256MBIT - Micron MT25QU256ABA
Optical Pulse Oximeter and Heart-Rate Sensor - Analog Devices Inc./Maxim Integrated MAX86141

It’s clear that this thing was glued shut, so I used acetone to try to loosen the adhesive while prying at the seams. I eventually managed to cut my way into the enclosure with a pair of small snips… destructively– this thing’s not going back together after what I did to it.

Inside the main body of the device, which is one solid piece of metal, the circuitry is secured with four tiny screws. After removing them, the whole circuit pops right out and we can see that it’s made of different types of PCB material wrapped around a battery. I ripped one of them accidentally while unwrapping it.

I can easily spot the major interactive components on this side of the board, including the LEDs for the heart rate and pulse ox sensors, the microphones, the button, the interface LED, and the charging pins. I invited over my electrical engineer friend David Cranor to take an in-depth tour of the circuit board. Don't miss the video above.

Most of the fancy parts in this device are hidden behind a metal can, potted in epoxy. We watched another expert's attempt to hot-air the can off, and everything else just came with it, leaving little hope for reading the part numbers on the ICs themselves. They used their advanced skills to make predictions about and reverse engineer the parts based on the traces on the circuit board itself, underneath the chips potted in epoxy. Definitely go check out this other teardown to read more on that.

I found out my science communicator friend Vanessa was also intrigued to do her own experiments with the device, so we joined forces. For more info on the behavioral science implications of the tone analysis feature, check out the video over on Vanessa’s channel.

Most of the exciting parts are behind this metal can