Modes

Modes can be cycled through with use of the Mode button. The Adj button typically does a secondary action such as edit, but this is dependant on the mode.

Static

Clock

The clock mode attempts to mimic the stock Casio clock. The clock shows the current time and the day of week. When the ( รท ) key is pressed, the full date is shown and the day of week.

Static

Setting Time and Date

  1. To set the time and date, press the ADJ button in the clock mode.

  2. Press the ( 0 ) key when editing the seconds to reset to zero.

  3. Press the MODE button to move the flashing selected digit as shown in the sequence below.
    Static

  4. A number can be entered by pressing the desired numeral key.

  5. Press the ADJ button to complete time setting.

Note
 AM or PM can be selected by pressing the ( PM ) key.
Note
 12 or 24 hours format can be selected by the ( + ) key.

Alarmclock

The alarm clock attempts to mimic the stock Casio alarm.

Daily Alarm

The daily alarm can be enabled by pressing the ( 4 ) key in the alarmclock mode. This will make the alarm sound once a day at the configured time.

Hourly Chime

The hourly chime can be enabled by pressing the ( X ) key in the alarmclock mode. This will make the chime sound every hour on the hour.

Static

Setting the Daily Alarm

  1. To set the daily alarm time, press the ADJ button in the alarmclock mode.

  2. Press the MODE button to move the flashing selected digit as show in the sequence below.
    Static

  3. A number can be entered by pressing the desired numeral key.

  4. Press the ADJ button to complete the alarm setting.

Note
 AM or PM can be selected by pressing the ( PM ) key. If the watch is in 24-hour mode this won’t do anything.

Timer

The timer mode provides a stopwatch and countdown timer.

Thermometer

The thermometer modes gives an approximate temperature of the watch PCB.

Power

The power mode gives an approximate voltage of the coin cell battery (VCC).

Settings

The settings mode gives a very basic interface to edit settings for modes. The settings are stored in EEPROM.

Update

The update mode provides an easy way to reboot the watch. By default the watch is reset into the bootloader, allowing firmware updates.

Uptime

The uptime mode provides a way to track battery life by giving a number of days since the counter was reset (Battery replaced).

Settings

Setting[0]

Configure 12/24 hour clock.

  • 0 - 24-hour clock

  • 1 - 12 hour clock

  • Invalid - Reset to 0

Setting[1]

RTC calibration value.

Setting[2-3]

Temperature calibration reading at 25C. 12-bit value stored as two bytes H:L.

Setting[3-4]

Uptime value stored as full days. 16-bit value stored as two bytes H:L.

Setting[5]

LCD voltage control. 3-bit value, the high 5 bits are ignored.

Updates

Updating the firmware can be done without disassembling the watch, provided you have the appropriate cable and software.

PowerPIC Watch Clip

[image of watch clip] [image of watch in clip]

The watch clip can be used to connect the PowerPIC to your computer. It uses the back of the watch for one-wire UART and the mode button for GND.

Uploading Firmware

New firmware can be uploaded with picchick — a python utility for uploading code to PICs.

picchick -d 16lf19197 -c flipflop -P <port> -f <firmware>.hex

Note that if you are building the firmware from source, there is a rule in the makefile to upload the built hex file:
make upload

Glossary

CasiOS

The "operating system" that runs on the PowerPIC.

mode

An application that runs on the PowerPIC.

github | documentation | website
© 2025 Rex McKinnon <0xFF@rexploits.com>