pi-clock

Simple clock powered by RaspberryPi & I2C driven 4x20 LCD panel

Building

$ sbt assembly

This generates the fat jar in target/scala-2.13/pi-clock-assembly-2.0.0.jar

Running

$ java -jar pi-clock-assembly-2.0.0.jar

Configuration

You can use environment variables to configure the application:

PI_CLOCK_CHECK_INTEGRITY : Exit with 0 status code (simple check for corruption; default: false)
PI_CLOCK_I2C_BUS_FOR_DISPLAY : The I2C bus of the display (decimal / hex; default: 0)
PI_CLOCK_I2C_DEVICE_FOR_DISPLAY : The I2C device address of the display (decimal / hex; default 0)
PI_CLOCK_LOG_DISPLAY_UPDATES : Should the device log detailed display updates to stdout (toggle text; default: off)
PI_CLOCK_LOG_TIMING_INFO : Should the device log details on how long delays and updates take (toggle text; default: off)
PI_CLOCK_DISPLAY_ENABLED : This can be switched off to test on a non-pi system (toggle text; default: off)
PI_CLOCK_DISPLAY_DIMENSIONS : The dimensions of the display (20x4 or 16x2)
PI_CLOCK_HUMAN_FRIENDLY : Should the display be human friendly; standard is ISO-8601 timestamps (default: false)
PI_CLOCK_BUTTON_ENABLED : Should the control button be enabled (default: false)
PI_CLOCK_BUTTON_PIN : The pin associated with the control button (cycles display mode)
PI_CLOCK_BUTTON_NC : Is the button normally-closed (default: false)
PI_CLOCK_CUSTOM_DISPLAY_FILE_PATH : Load custom display lines from this file.
PI_CLOCK_INTERNET_HEALTH_CHECK : Should the device perform regular Internet health checks (default: false)
PI_CLOCK_INTERNET_POWER_PIN : The GPIO pin to which the power relay is connected
PI_CLOCK_INTERNET_POWER_HIGH : Power is on when the power pin is pulled high (default: false)
PI_CLOCK_INTERNET_CHECK_INTERVAL : Frequency at which to perform Internet health checks (default: 1m)
PI_CLOCK_INTERNET_CHECK_TIMEOUT : Health check HTTP request timeout (default: 5s)
PI_CLOCK_INTERNET_OUTAGE_DURATION : Outage duration required for an Internet connection reset (default: 5m)
PI_CLOCK_INTERNET_RESET_DELAY : Minimum delay between Internet connection resets (default: 15m)
PI_CLOCK_HEALTH_SLACK_WEBHOOK : Slack webhook for health checks.
PI_CLOCK_SENSE_HAT_INSTALLED : Sense-hat system is installed (default: false)
PI_CLOCK_NOTIFICATION_SLACK_WEBHOOK : Slack webhook for notifications.

Notes

The control logic is ported from the C++ Arduino library LiquidCrystal_I2C

Wishlist

Add custom Internet/network URLs for health checks
Add option to disable network checks

Pin Connections

| Display | |=======================| | GND-------------- | | VCC------------ | | | SDA----- | | | | SCL--- | | | | . | | | | . | | | |
| | | |
. | | | | . | 3.3V | | o o | | 5V | | SDA | -- o o-- | 5V | | SCL ---- o o---- GND | |=======================| | Raspberry Pi |

Identifying I2C Device Address

Install the tools

sudo apt install i2c-tools

Make sure that the I2C interface is enabled (raspberry pi settings, may require a reboot).
List I2C devices

i2cdetect -y 1

joeledwards / pi-clock