Teardown Tuesday: Wearable Audio Recorder

May 17, 2016 by Alex Udanis

Never miss that cute moment again! Kapture is a unique audio recorder that constantly records. What's inside of it?


Never miss that cute moment again! Kapture is a wearable audio recorder that constantly records. A double tap to the device saves the previous minute of audio. The Kapture is then able to sync its ‘klips’ back to your smartphone via its companion app! 


Kapture audio recorder 



The Kapture audio recorder syncs its data through the Kapture app. The app allows you to save, name, tag, and edit clips. Additionally, the app also offers the option to record audio and save the last minute just like the wearable device.


The Kapture iOS app 


Physical Hardware


The wrist strap on the Kapture audio recorder 


One of the major selling points of the Kapture audio recorder is how customizable it is. Unlike some other wearables, this device has a fully replaceable wrist strap. The wrist strap is a two-piece design that latches onto the body of the device. Wearing this device isn't limited to a wrist— there's also a Pocket Clip available as an option.


The body of the audio recorder  


In addition to having a changeable wrist strap, the Kapture also has a changeable faceplate. The faceplate simply slides off once the wrist strap is removed. The faceplates are available in more than eight different colors.




The 135mAh lithium battery 


Powering the Kapture audio recorder is a single-cell lithium battery. The internal battery is relatively small, with a capacity of 135mAh and measurements of 3mm * 23mm * 23mm. This small battery gives the Kapture a life of around 15 hours depending on the usage.




The charger to the Kapture recorder 


The Kapture charges over a USB cable with a two-terminal, magnetic charging cable. On the backside of the wearable are the gold-plated charging contacts and two small indentations to ensure the charger is properly aligned.


The back of the Kapture 


Once the wearable is opened, you can see two gold-plated, spring-loaded pins that make contact with the circuit board. There are also two relatively large rare earth magnets that are viewable.


Internal spring-loaded pins and magnets 




The Bluetooth module inside of the Kapture 


In order to transmit the audio data back to the associated smartphone app, the Kapture audio recorder relies on a Bluetooth connection. Inside is an STMicroelectronics SPBT2632C2A Bluetooth module (PDF). This is a complete Bluetooth module that is FCC-certified and has an integrated antenna, visible in white in the image above.




The vibration motor that relays information 


The Kapture uses two methods to communicate status the end user. The first method is a vibration motor. The wearable vibrates when the user saves audio and also when the audio is done saving. This vibration is caused by a small motor with a rubber casing and an asymmetrical counterweight on the shaft.


The status LED that relays even more information 


The second method the Kapture uses to indicate its current status to the end user is a bi-color led. This LED is used for many uses such as charge status indication, power-on indication, and Bluetooth pairing indication.




The microchip technology 64Mbit flash memory 


To store the audio clips, the Kapture relies on a 64Mbit flash memory IC from Microchip Technologies. The 64Mbits on the SST26VF064B (PDF) IC permits the Kapture to store “about 25” clips, according to the manufacturer. The Kapture records each audio clip at an 8kHz sample rate with 4-bits per sample.




The 32-bit PIC microcontroller  


At the heart of the Kapture is a 32-Bit PIC microcontroller, a PIC32MX170F256D-I/TL. This microcontroller has 256kbit of program storage, 31 IO pins, 13x 10 bit ADC channels, 40MHz clock speed, and support for many communication protocols. All of this is packed into a 44-VFTLA Exposed Pad package.




The 3-axis NXP accelerometer 


To initiate a recording on the Kapture, two relatively slow and intentional taps are required. To measure these taps, a 3-axis accelerometer is used to detect the impacts. A MMA8453Q accelerometer from NXP Semiconductor is used. This sensor communicates over an I2C bus to relay its data with up to a 10-bit resolution. 




The microphone board in the Kapture 


The primary feature of the Kapture is the ability to record audio. The Kapture uses an omnidirectional MEMS microphone paired with an op-amp on a secondary circuit board. The microphone the audio recorder uses is an INMP404ACEZ-R7 (PDF) manufactured by InvenSense. Paired to the microphone is an op-amp made by Analog Devices that is used to amplify the signal.



The Kapture follows the growing trend of connected and always-on smart devices. With its always-on recording, the deliberate double tap it takes to save a recording, and its powerful companion app, this device works as advertised. While this device may not be for everyone, if you are looking for a way to save conversations after they happen, this is certainly a viable option for you. There is a lot of technology and innovation packed into this little device. 

A big thank you to Kapture Audio for sending us this recorder and making this teardown possible! 

Thanks for looking at this week's Teardown Tuesday!   


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