SMART-CLOCK

Kernel device manual

Contents:

1. Hardware connection

1.1 Hardware connection to Raspberry 40 pin extension.

1.2. Enable SPI, I2C and DTBO in Raspberry config.

1.3. Disable time synchronization on Raspberry.

1.4. Module installation.

1.5. Removing the module from memory

2. User manual

2.1 Main functions

2.1.1. Time

2.1.2. Timer

2.1.3. Alarm

2.1.4. Temperature and Pressure

2.1.5. Pedometer

2.1.6. Game

2.1.7. Options

2.1.8. Making of screenshots

2.1.9. Display BMP files

2.1.10. Notifications bar

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1. Hardware connection

Hardware connection to Raspberry 40 pin extension:

Connect TFT Module (SPI):

VDD3.3-> 3,3v (pin 1)

CS -> SPI0_CE0 (pin 24)

SCL -> SPI0_SCLK (pin 23)

SDA -> SPI0_MOSI (pin 19)

RS -> GPIO_23 (pin 16)

RST -> GPIO_24 (pin 18)

GND -> GROUND (pin 25)

Connect bmp280 sensor (I2C):

VIN -> 3,3v (pin 1)

GND -> GROUND (pin 25)

SCL -> SCL1 i2c (pin 5)

SDA -> SDA1 i2c (pin 3)

 

 

Connect mpu6050 sensor (I2C):

VCC-> 3,3v (pin 1)

GND -> GROUND (pin 25)

SCL -> SCL1 i2c (pin 5)

SDA -> SDA1 i2c (pin 3)

AD0 -> 3,3v (pin 1)

 

Connect rtc3231 (w/o eeprom) (I2C):

+ -> 3,3v (pin 1)

- -> GROUND (pin 25)

C -> SCL1 i2c (pin 5)

D -> SDA1 i2c (pin 3)

 

 

Connect hardware button (2 pin):

Pin1 -> 3,3v (pin 1)

Pin2 -> GPIO_17 (pin 11)

 

 

 

1.2. Enable SPI, I2C and DTBO in Raspberry config:

you can enable SPI, I2C from the /boot/config.txt file. Open a terminal window and enter:

sudo nano /boot/config.txt

Look for a line that reads #dtparam=spi=on and remove the # symbol. Do the same for #dtparam=i2c=on and

dtparam=i2c_vc=on. Now add a line with dtoverlay=smart_clock.dtbo so dtbo overlay will be connected at boot time

Reboot your Pi.

1.3. Disable time synchronization on Raspberry.

By default, Raspberry is using time-synchronization service while connected to network.

We need to disable it, because time we use from rtc clock.

sudo systemctl stop systemd-timesyncd

sudo systemctl disable systemd-timesyncd

1.4. Module installation

Building the Module and device-tree overlay:

1. make [KDIR=[Path to your linux kernel]]

2. The module will be compiled to smart_clock.ko

3. The device tree overlay will be compiled to smart_clock.dtbo

4. Copy smart_clock.dtbo to boot/overlays directory to the device

5. Inserting into your kernel:

Type command in terminal:

sudo insmod smart_clock.ko

After check kernel log if device is properly booted:

smart_clock: smart_clock: Major = 238 Minor = 0

smart_clock: gpio_button: found gpio #17 value in DT

smart_clock: st7735fb: init

smart_clock: st7735fb: probe started

st7735fb spi0.0: SPI ok

smart_clock: st7735fb: Total vm initialized 40960

smart_clock: bmp280: probing

smart_clock: bmp280: probed

smart_clock: ds3231: probing

smart_clock: ds3231: probed

smart_clock: ds3231: set time of the day from RTC result 0

smart_clock: mpu6050: probing

smart_clock: mpu6050: probed

if some of devices will fail to start, you will get the message with hardware name: probe failed. Check hardware connection or config.txt

If "set time of the day from RTC" result is other than 0 than your rtc is not activated or battery is too low, once you setup clock or alarm this will be fixed automatically.

1.5 Remove the module from memory

Command:

sudo rmmod smart_clock.ko

module will be removed when the last timer is stopped. Check kernel log if device is properly removed:

smart_clock: controls unloaded

smart_clock: sensors unloaded

smart_clock: gpio_button: device exit

smart_clock: st7735fb: exiting

smart_clock: st7735fb: unloaded

smart_clock: module unloaded

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2. User manual

2.1 Main functions:

Smart clock is designed to work as simple smart-watch with

entertainment part. Functions:

-Time

-Alarm

-Timer

-Temperature and Pressure

-Pedometer (Steps meter)

-Game

-Making of screenshot (BMP format) (2.1.7)

-Display BMP files (2.1.7)

Customization is also possible through options:

-24h or AM/PM

-Temperature view in C/F

-Enable or disable the Alarm

Functions are controlled by one button:

-click (Short press)

-middle-long (Press and hold about 1 sec)

-long click (Press and hold longer than 1 sec)

2.1.1. Time

Hold the button longer than 1 sec to enter first view mode.

Current time will be loaded from "rtc"

Clock view can be customized by showing time in format 24h or AM/PM

In Options view.

Adjusting the time:

Use middle-long button action to enter adjustments mode.

Adjustment's part will be blinking. Press short the button to adjust.

To switch the adjustments to the next part hold button long click

1st adjustments will be minutes, 2nd - hours, 3rd day of the month, 4th the month, 5th year (year is capped to 2050)

Once you finish the adjustments - clock value will be automatically stored in rtc.

Use long click to switch mode to next mode: Timer

2.1.2. Timer

Timer can be started and stopped by short pressing of the button.

To reset the timer -stop timer and use middle-long button action.

Timer can be run in background while view is switched. Use long-press button action while timer is running to switch the view while timer is running in background. The notification of running timer will be shown in notification bar.

Switch to the next view Alarm press long press button.

2.1.3. Alarm

The alarm can be turned on and off in Options view.

When Alarm is triggered the message "ALARM !!!" will appear blinking on screen, short press the button to disable it.

Adjusting the alarm

Use middle-long click to enter adjustments mode.

Adjustment's part will be blinking. Press short the button to adjust.

To switch the adjustments to the next part hold button long action

1st adjustments will be minutes, 2nd -- hours

Once you finish the adjustments -- alarm values will be automatically stored in rtc.

2.1.4. Temperature and air pressure.

Temperature can be shown in C or F. Check Options for the option.

Switch the next view Pedometer press long-press button.

2.1.5. Pedometer.

Pedometer or Step meter shows steps (or vertical shakes) from the device start.

To reset the pedometer short press the button.

Switch the next view Game press long-press button.

2.1.6. Game

Besides of pedometer the mpu6050 is also used for the control of the game "SNAKE".

Tilt the device left, right, up, down to control the snake and eat the fruit.

Once snake eats herself or touches the white merges -- the game will be over.

To Restart game short press the button.

Switch the next view Options press long-press button.

2.1.7. Options

Adjusting the options:

Use middle-long click to enter adjustments mode.

Adjustment's part will be blinking. Press short the button to adjust.

To switch the adjustments to the next part hold button long click

Note: Once you finish the adjustments -- alarm values will be automatically stored in rtc.

2.1.8. Making of screenshot (BMP format)

Use terminal in your Raspberry to type the command:

cat dev/smart-clock

to get file stream of bmp image of your current screen.

Example:

cat dev/smart_clock > screen.bmp

It will create new file screen.bmp with the screenshot from your device.

2.1.9. Display BMP files.

Use terminal in your Raspberry to print to device the command:

cat screen.bmp > dev/smart_clock

The file will be displayed on screen.

Note: Only files with resolution less than 160x128 are supported. Otherwise, you will receive the error message.

2.1.10. Notifications bar.

When alarm is enabled in options -- the icon "Alarm" will be shown is notification bar on screen.

When timer is running in background -- the icon "Clock" will be blinking in notification bar on screen.

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