TW64 Smart Bracelet

7 May 2015


There are many different types of smart bracelets in the market.  The most common ones are branded under Fitbit,  Garmin,  Xiaomi but the most popular one appears to be a brandless bracelet called TW64.

What is a Smart Bracelet? 

Smart bracelet is nothing but an electronic counter that can be connected to the handphone and/or computer through a Bluetooth network for data logging. Various brands have come up with different functions  for such  bracelets.  Most use it to count the number of walking steps.  Others use the counter to work out calories consumed,   sleeping movements,  time alarms etc.  Many bracelets have a built-in time clock enabling the bracelet to be used also as a watch.   The more sophisticated ones like FitBit has in-built a height sensor,  enabling proper logging of step countings,  up and down a staircase.

What's Good About Smart Bracelet? 

1.  It takes record of your foot step, It will always help you to "challenge" your own self that you can always make longer and longer walk.   The recommended daily walking step is 10,000 steps for a healthy person according to American medical research institutions.  Once one has taken exercising to be a daily routine and walk or run  10,000 steps,  one would feel very uneasy to stop walking

2.  If the bracelet counting is website based, it will enable your bracelet to be "monitored" by the vendor like FitBit.  One might be able to use the records to get premium discount from some Health Insurance Companies.

What is TW64 and why it is popular? 

TW64 has been marketed under several brand names.  It has a twin 64K RAM and a 64K ROM all inside a Quintic 2021 system-on-microprocessor chip (SOC) which consumes ultra low power.  The abbrev "TW" could stand for the word TWIN.  TW64 is popular because it is one of the most affordable bracelet that has almost every function of the more expensive cousins.      

What are the main functions?

1. A 24 hours clock with running dates and a battery counter
2. A pedometer that registers walking step counting which is used to calculate the distance traveled and the calories burnt.
3. Other functions such as vibration reminder,  alarms,  sleep monitoring etc

Construction 

The chip,  Quintic 9021,  is enclosed inside a plastic casing measuring about 17mmx40mmx10mm.  The back case can be easily removed by 4 small screws to expose the inside electronic as shown.  Unlike other bracelets  it  allows the battery to be replaced.

Synchronising 

Like any other smart bracelet,  one can synchronise TW64 to the Android or Apple handphones through bluetooth using a free software called "MOVNOW plus", downloadable from Google Playstore or Apple Store.    Unlike Fitbit or other more sophisticated smart bracelet,   MOVNOW is not web-based and therefore,  could only be synchronised using handphones.

Performance 

The TW64 was tested with a full charge and compared it against a Fitbit Flex by wearing them together on the same wrist as shown.

The sets are then taken for a 6 km walk and the results are compared as shown

It can be seen that TW64 and Fitbit Flex have quite similar step counting.  It is well within the 10% error range.

The Battery and capacity 

The battery is a lithium-ion polymer type of either 40mAH or 60 mAH capacity. The test set came with a 60mAH battery and the vendor claimed it is able to handle  at least 7 days usage and 100 days standby.  After 5 days’ testing,  the test set still have 3/5 of the charge as indicated by the battery indicator.

Pros and Cons

Pros

1. It is very affordable,  priced around SGD$20/= including shipping from Q0010
2. It is not bad looking.  The bracelet material feels like silicone and has a look like FitBit Charge or other more sophisticated and expensive model
3. Long lasting battery that can be used for 7 days or more on a 60 mAH battery
4. Can be used as a watch
5. The battery is replaceable
6. Can be used without the handphone

Cons

1. The software is not web-based and therefore,  the data loggings or recordings might not be accepted by Health Insurance company for any discount in health premiums
2. The vibrator is soft and the vibration might not wake up some heavy sleeper ;  moreover,  the wake up alarm will sound only once.
3. It is only splash proof;  meaning,  cannot be worn for swimming.
4. Must synchronise to the phone regularly or the data would be lost. However,  the bracelet can store some data over nights for next synchronisation.

Things to watch out when buying TW64 

1. There are many brands offering various model of TW64.  Some are older model that can only used for older Android phones or iphones that have Bluetooth of 3.0 or lower
2. Go for TW64 which has 60 mAH battery as the battery will last longer. 

Things to watch out when using TW64 

1. The weakest part is the 3 charging contacts.  Clean them every time with a paper tissue after each long walk to get rid of the sweat.

1. Do not wear it for swimming though there is no problem wearing it during showers.  
2.  

QN902X Application Notes

The application notes on QN902X can be found here.