Authors

watch this video!

David Amma (d-amma@ti.com)
Andreas Lechner (lechner@ti.com)

Features

Eco friendly: works on solar energy with fallback to battery power if not enough light
Backlit display with autoenable in bright sunlight (also manually in menu)
Radio clock: sync with the atomic clock of the PTB
reminds you when the Daylight Saving Time is in effect (next to the time a 'S' is displayed)
Sync your Chronos: works with all 868MHz Chronos without needing a firmware update (change define for 915MHz)
calibrates the internal temperature sensor of the Chronos and allows you to set your current altitude
allows to set the Chronos Alarm Clock
easy to use: intuitive menu with key options being displayed in the bottom line of the display
Diagnostic Menu: See the current voltage levels of both Solar and Battery power rails

Pictures & Videos

Be sure to check out our great Video. Remember to turn on sound ;-)

To navigate the menus just look at the bottom line to see the assigned function. Usually one needs the two big buttons to navigate and the onboard button to OK or return to main screen.

main screen

menu screen

eagle layout

schematic

Inspiration / Market

While using the Chronos we noticed a considerable drift of the clock in relation to our Radio Clock in a matter of mere days. We noticed it was possible to sync the Chronos via the TI control center but thought it to be quite a hassle to always have to activate the PC and needing to sync the PC clock via the internet first.

Also every Chronos seems to have quite a huge offset when it comes to displaying the correct temperature. With our product this is now easily solved since we have a high precision TI temperature sensor on board which allows us to calibrate the offset automatically. And since the altitude is calculated with the barometric pressure -which changes over time depending on the weather- it becomes necessary to reset your absolute altitude to compensate the barometric drift.

This can now all be done with the press of a single button, so it mainly targets an audience who loves exact data on his/her Chronos combined with an easy to use interface and a nice standalone clock for your desk.