# W800_Smart_Watch
## Why this project :
I was interested in working on a bigger project with more challenges and which could be useful.  
I am also quite unhappy with the smartwatches that are on the market (expensive, no access to the firmware, data collection and privacy issues), that's why I decided to try doing my own that I can fully customize. This is going to be a long adventure with a lot of discoveries along the way :).  
I also wanted to test this W800 SOC more deeply and see what it could do and I think it is a perfect fit for the project.  
So let's go !

## A Smart Watch project using the Chinese W800 SOC.
The W800 is a pretty interesting chip with impressive characteristics for its price (around 1$) :    
### Core :  
* 32bit XT804 CPU
* 240 Mhz frequency  
### Memory :
* 2 MB on chip flash
* 288 KB RAM  
### Wireless connectivity :
* Bluetooth EDR(Classic) and BLE 4.2
* WiFi 2.4Ghz 802.11 b/g/n


## Sensors :
The goal is to embed the following sensors in the watch :
* An accelerometer (for wrist tilt detection, single and double tap detection , foot step counting and more)
Possible choices :
    * ADXL345
    * MPU6050
    * BMI160
    * LSM6DS3
    * BMA456 <-- **SELECTED** i2c addr : 0x18 or 0x19 7 bit address, has the wrist tilt detection feature.
* A magnetometer (possible choices):
    * HMC5883L <-- After reading some comparison articles between the HMC5883L and QMC5883L and the datasheets, the later seems better in term of perfomances.
    * QMC5883L <-- **SELECTED** i2c addr : 0x0D 7 bit address, better soldering footprint
    * LSM303DLHC
    * BMM150 <-- Package with balls, hard to solder
* An air pressure/temperature sensor (to display the altitude for example)
    * BMP280 <-- **SELECTED** i2c addr : 0x76 or 0x77

## Actuators :
* A vibration motor to notify events to the user.
* ~~A piezo buzzer~~ : dropped, maybe in next version.

## Power source :
* 1 cell lipo 450 mAh battery.
* A charge/discharge controller.

## Screen + touch element :
* [Screen with touch](https://fr.aliexpress.com/item/1005004887834918.html?spm=a2g0o.order_list.order_list_main.22.340a5e5bX8WCb0&gatewayAdapt=glo2fra) : GC9A01 with touch panel. It uses the required 4 line Serial Interface.
* Touch element i2c addr : 0x15, CST816D I2C touch driver.

## Programming and charging :
* The smart watch programming and charging is done through the same USB port  
using a magnetic 4 pin plug.


## MCU Pin assignement table :
| Pin Number | Pin Name | Type | Function | Pull UP/DOWN| Connected to | Comment |
|------------|----------|------|----------|-------------|--------------|---------|
||PB_20|I/O|**UART0_RX**/PWM1/UART1_CTS/I²C_SCL|U/D|**USB/Serial TX flash pin**||
||PB_19|I/O|**UART0_TX**/PWM0/UART1_RTS/**I²C_SDA**|U/D|**USB/Serial RX flash pin** and **BMA456, Touch Panel, HMC5883L and BMP280 SDA pins**||
||WAKEUP|I|**External Wake Up Pin**|D|**BMA456 IRQ line** and **Touch Panel IRQ line** through NAND Gate|The chip is waken up when the pin is HIGH|
||RESET|I|Reset Pin|D|**Micro switch** and **USB/Serial RTS pin**||
||XTAL_OUT|O|External crystal output||||
||XTAL_IN|I|External crystal input||||
||AVDD3V3|P|Chip power supply, 3.3V||||
||ANT|I/O|RF Antenna||||
||AVDD3V3|P|Chip power supply, 3.3V||||
||AVDD3V3|P|Chip power supply, 3.3V|||
||AVDD3V3_AUX|P|Chip power supply, 3.3V||||
||TEST|I|Test function configuration pin||||
||BOOTMODE|**I/O**|BOOTMODE and I²S_MCLK/LSPI_CS/PWM2/I²S_DO|U/D|**Touch Panel Reset line**||
||PA_1|I/O|JTAG_CK/**I²C_SCL**/PWM3/I²S_LRCK/ADC0|U/D|**BMA456, Touch Panel, HMC5883L and BMP280 SCL pins**||
||PA_4|I/O|JTAG_SWO/I²C_SDA/PWM4/I²S_BCK/**ADC1**|U/D|**Battery resistor voltage divider output**||
||PA_7|I/O|**PWM4**/LSPI_MOSI/I²S_MCK/I²S_DI/Touch0|U/D|**LCD backlight N-MOSFET driver**||
||VDD3V3IO|P|IO power supply, 3.3V||||
||PB_0|I/O|**PWM0**/LSPI_MISO/UART3_TX/PSRAM_CK/Touch3|U/D|**Vibration motor control pin**||
||PB_1|**I/O**|PWM1/LSPI_CK/UART3_RX/PSRAM_CS/Touch4|U/D|**Touch Panel IRQ line**||
||PB_2|I/O|PWM2/LSPI_CK/**UART2_TX**/PSRAM_D0/Touch5|U/D|**Debug UART serial output**||
||PB_3|**I/O**|PWM3/LSPI_MISO/UART2_RX/PSRAM_D1/Touch6|U/D|**TP4056A Charging Signal**||
||PB_4|**I/O**|LSPI_CS/UART2_RTS/UART4_TX/PSRAM_D2/Touch7|U/D|**TP4056A Charged Signal**||
||PB_5|**I/O**|LSPI_MOSI/UART2_CTS/UART4_RX/PSRAM_D3/Touch8|U/D|**Battery resistor voltage divider enable**||
||VDD3V3IO|P|IO power supply, 3.3V||||
||CAP|I|External capacitor, 4.7µF||||
||PB_6|I/O|UART1_TX/**MMC_CLK**/HSPI_CK/SDIO_CK/Touch9|U/D|**LCD Serial Clock Pin**||
||PB_7|I/O|UART1_RX/**MMC_CMD**/HSPI_INT/SDIO_CMD/Touch10|U/D|**LCD Serial Data Pin**||
||PB_8|**I/O**|I²S_BCK/MMC_D0/PWM_BREAK/SDIO_D0/Touch11|U/D|**LCD Data or Command Selection Pin**||
||PB_9|**I/O**|I²S_LRCK/MMC_D1/HSPI_CS/SDIO_D1/Touch12|U/D|**LCD Reset Pin**||
||PB_10|**I/O**|I²S_DI/MMC_D2/HSPI_DI/SDIO_D2|U/D|**LCD Chip Select Pin**||
||VDD3V3IO|P|IO power supply, 3.3V||||
||PB_11|**I/O**|I²S_DO/MMC_D3/HSPI_DO/SDIO_D3|U/D|**BMA456 IRQ 2 line**||
||GND|P|Ground (Central Pad)||||

## What is done/working so far :
* LVGL 8.3.3 running on the SOC using DMA.  
    * Supported LCD drivers : 
        * ILI9341 in 4-line serial mode (8 bits) with D/C pin
        * ST7789 in 4-line serial mode (8 bits) with D/C pin
        * GC9A01 in 4-line serial mode (8 bits) with D/C pin
    * Supported LCD touch screen :
        * CST816D capacitive touch ic.
    * Three screens designed and working with LVGL : 
        * 1 watch face based on a casio watch.
        * 1 menu list screen with icons.
        * 1 setting screen with basic settings (date and time + display brightness) (work in progress).
* Debug UART on PB_2 (output only)
* Wake up interrupts handling :
    * Wrist tilt MCU wake up working
    * LCD touch wake up
* Sensors/Actuators :
    * QMC5883L driver working
    * BMA456 driver working
    * BMP280 driver working (temperature + pressure)
    * Battery voltage sense using ADC is working
    * Vibration motor controlled by PWM working

## To do :
* Write I2C drivers for the :
    * [X] BMA456
        * [X] Wrist tilt detection
    * [X] BMP280
        * [X] Temperature
        * [X] Pressure
    * [X] QMC5883L
* [X] Write the init sequence for the GC9A01 LCD driver.
* [X] Make LCD display + touch work.
* [X] Design and test battery voltage sensing circuit -> voltage divider bridge because ADC input can sense 2.5V Max.
* [ ] Finish to design the settings page.
* [ ] Implement a good algorithm to handle adaptiv MCU clock to save power
* [X] Test the charge circuit.
* [X] Handle watch auto sleep feature with wake up on screen touch + wrist tilt (POC could be improved).
* Design and test the : 
    * [X] vibration motor circuit
* [X] Draw the schematic, the first revision of the schematic is available [here](design/Kicad/W800_Smart_Watch/W800_Smart_Watch.pdf).
* [X] Design the PCB (routing, placement etc..) on a 2 layer PCB - done.
* [ ] Update the W800 SDK from version 1.00.08 to version 1.00.10 released in January of 2023.

## Achieved power consumption recap:  
(Need to work on sleep current :-( )
|         Mode             | Current draw | Estimated battery life (450 mAh lipo) |
|--------------------------|--------------|---------------------------------------|
|Active (40Mhz clk)<br>(No BLE / No WiFi) |~52 mA        | ~8 hour                |
|Active (240Mhz clk)<br>(No BLE / No WiFi) |~72 mA        | ~6 hour               |
|Sleep                     |~4.5 mA       |~4 days and 4 hours                   |
|Standby                   |~1.8 mA       |~10 days and 15 hours                  |

## Some screenshots of the achieved visuals currently running on the watch using lvgl :
![](http://82.64.196.164/images/git/watch_graphics.png)

## Here is a preview of what the PCB should look like :  
### The front :
![](http://82.64.196.164/images/git/rendering_front.png)

### The back :
![](http://82.64.196.164/images/git/rendering_back.png)