Description
As recently stated on hack a day:
“A timepiece is rather a rite of passage in the world of hardware hacking “Presenting: A personal time base.
Depending on current location, elevation, and velocity we all experience very real time dilation effects. Time does not pass at the same rate for everyone. The “Project GREAT” experiment in 2005 measured a 20 to 30 ns shift during a weekend family trip to Mt Rainier.
The idea is to continuously monitor and record cumulative time deviation.
“A timepiece is rather a rite of passage in the world of hardware hacking “Presenting: A personal time base.
Depending on current location, elevation, and velocity we all experience very real time dilation effects. Time does not pass at the same rate for everyone. The “Project GREAT” experiment in 2005 measured a 20 to 30 ns shift during a weekend family trip to Mt Rainier.
The idea is to continuously monitor and record cumulative time deviation.
This project uses a Rubidium atomic frequency standard to continuously track local time dilation effects relative to:
Electrical Frequency Controlled (EFC) Ovenized Crystal Oscillator (OCXO)
GPS with battery backup for internal RTC
WWVB US atomic clock radio frequency signal
(3) x Temperature Compensated RTC modules with independent battery backup
Electrical Frequency Controlled (EFC) Ovenized Crystal Oscillator (OCXO)
GPS with battery backup for internal RTC
WWVB US atomic clock radio frequency signal
(3) x Temperature Compensated RTC modules with independent battery backup
Details
Thanks to comments from Doc Pedersen and nsayer, I ordered an Electrical Frequency Controlled (EFC) Ovenized Crystal Oscillator (OCXO) with TTL output to improve the short term stability.
It is a muRata OC2545-DT 10.00 MHz OCXO Crystal Oscillator.
OC2545-DT Datasheet
Thanks to the commenters I now have some new parts on hand:
muRata OC2545-DT 10.00 MHz OCXO Crystal Oscillator
12 bit i2c DAC board (To generate the control voltage – Delta Sigma w/Filter)
Ad a fruit Si5351 Clock Generator Breakout (To generate microcontroller clock)
RS232 to TTL converter board
ESP8266 ESP-12E Node MCU
An I2C multiplexer board allows for more than one RTC module (Since these have a hard coded I2C address you can normally only use one). I went for three – One tracking GPS time, another tracking the rubidium standard, and the last one as a control or reference clock – without compensation.
Read More: Rubidium Disciplined Atomic Clock
It is a muRata OC2545-DT 10.00 MHz OCXO Crystal Oscillator.
OC2545-DT Datasheet
Thanks to the commenters I now have some new parts on hand:
muRata OC2545-DT 10.00 MHz OCXO Crystal Oscillator
12 bit i2c DAC board (To generate the control voltage – Delta Sigma w/Filter)
Ad a fruit Si5351 Clock Generator Breakout (To generate microcontroller clock)
RS232 to TTL converter board
ESP8266 ESP-12E Node MCU
An I2C multiplexer board allows for more than one RTC module (Since these have a hard coded I2C address you can normally only use one). I went for three – One tracking GPS time, another tracking the rubidium standard, and the last one as a control or reference clock – without compensation.
Read More: Rubidium Disciplined Atomic Clock