I had bought a Goqii Fitness Tracker and it was lying for a while unused. I had lost the charger somewhere. So I opened it today and here is a teardown analysis with pictures.
I bought it for 2000 rupees and it looks like this
GOQii Vital – Colour Display Blood Pressure Monitor with 3 Months Personal Coaching, Adult (Black)
The rubber band sits the mechanical in pouch sort of thing. The mechanical casing houses the all the electronics and rechargeable battery. There are two pins exposed that are used for charging the battery.
Internal electronics is designed in four layer
- Filament like touch connected to main PCB by single wire
- Display connected to main board through a flex connector
- Main board
- Battery and vibrator
The box build does not use any sealing from inside. There is a coating from outside which gives it some IP sealing and the casing cannot be opened without using a knife.
There are two sets of wire running between battery and vibrator. These wires are directly soldered onto the PCB. There are no connectors used maybe for cost saving.
Parts used on the design
- Battery (3.7V, 70mAH)
- Vibrator (Attached to the battery using some bonding material)
- 5 sets of Wire
- One bolt to hold the PCB
- Touch Sensor
- Display
- Main PCB
Parts used on the PCB
- Bluetooth IC (CC2541) – A TI Chip providing BLE support with 8051 Core. Package of VQFN-40 and complete part number CC2541F256RHAT. 256Kb of Flash and 8Kb of RAM. This is the core of the electronics design. Mouser Price – Rs 128.93 (5K peices)
- Serial EEPROM (24C512A) – 512Kb of serial memory. Rs ₹49.55 (5K peices)
- RTC (PCF8563) – Real time clock and calendar. ₹19.78(10K peices)
- Touch Sensor IC (PCF8883) – The touch/proximity sensor IC that detects change in capacitance on the remote plate the we see on the top of the display. It was little difficult the read the IC marking and it is quite away from the Touch Sensor plate connection on the board. ₹41.85 (10K peices)
Apart from there are discrete parts (mostly 0201 with few 0402 parts), transistors, crystals, antenna and connector.
The display is connected the main pcb by a 15 pin flex pcb connection and pasted on the main PCB.
Bluetooth antenna is a PCB antenna and has metal around.The vibrator is somewhat on the top of the antenna but the Bluetooth connectivity is okay when kept close.
All the prices is have been taken from mouser and only the IC costs comes around ₹240.11 which will much lesser depending on the volume pricing.
Add another ₹400 for the packaging, battery, display, touch plate, wires. There is going to be a lot of NRE with tooling for mechanical, touch plate, PCB etc. which will be there for any hardware product.
Overall quite compact design of the PCB with components only on the one side with few test points on the other side where display has been pasted. Basic touch functionality by metal plate right under the top plate.