The intended application of the Amazon Dash Button
Amazon launched the Dash button in July 2015 to provide an easier way for customers to make purchases. Inside the device is a plethora of technology that makers have been hacking and modifying to suit their own needs. Today, I'll be giving a breakdown of some of the electronics inside the device. On the surface, the Dash button appears to have a push button switch, a WiFi modem, LEDs, and a power source. Opening up the device, there's a fair amount more packed inside.
The top of the Amazon Dash circuit board.
The battery located on the back of the Dash button. Take a look at the spot welds!
The Dash Button is powered by an Energizer L92-FR03; this is a primary lithium battery designed for low self-discharge (20-year shelf life printed on the battery, although the datasheet only says 15 years) and high capacity (1250mAh). This single 1.5V cell has tabs spot welded on to both terminals. With the low current draw that many of the components have, a multi-year battery life should be easily achievable.
The switching boost regulator on the Dash.
The voltage from the battery gets converted to 3.3v through the use of a TI TPS61201 boost regulator. This is labeled as 'U1' on the ‘back’ of the circuit board. It also appears that the rest of the associated parts, such as the inductor (L1); and the input and output capacitors, are placed in close proximity.
The MEMS microphone on the bottom of the circuit board. 6 spot welds on the positive terminal of the battery.
In order to transfer the WiFi information to the Dash, it has a microphone that receives encoded data from a smart device with a speaker. The Dash uses an InvenSense INMP441 MEMS microphone to receive that data. This component is also on the rear of the circuit board labeled as 'MF1'.
The WiFi module is the silver component with the 2D barcode.
The other side of the circuit board reveals plenty more components. The WiFi module stands out the most; it is a Broadcom BCM43362. This is labeled as 'U9'. This is a similar WiFi module to the one that's used in the Particle.io Photon.
The ST microcontroller in a chip level package.
The microcontroller on the Amazon Dash is the ST STM32F205. It lies in a package called a Wafer Level Chip Scale Package (WLCSP). The STM32F205 is a 32 bit ARM Cortex M3 microprocessor. The microcontroller is labeled 'U5' on the circuit board.
The flash memory can be seen at the top of the circuit board labeled U6.
A flash memory module is also on the Amazon Dash, this is labeled 'U6'. This is a 16Mbit flash module made by Micron that communicates over SPI.
There have been many makers hacking this button in various ways to suit their needs. For $5, it's a low-cost option for makers to turn into an IOT device. Take a look at some of the projects people have done so far:
Are you working on a project with the Amazon Dash? Let us know in the comments below!
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