TCXO TCXO RTC Raspberry Pi Hat, part 2 The motivation for this project is NTP servers in datacenters - it can be expensive to get a GPS antenna on top of other people's buildings with a wire running down into your
ntp TCXO RTC Raspberry Pi Hat History I'm bringing my RTC Hats [https://blog.dan.drown.org/tag/stratum2/] back online (source code [https://github.com/ddrown/stm32-input-capture-f031] and hardware design [https://github.com/ddrown/stm32-input-capture-f031/tree/master/hardware]
stratum2 Drift One of my goals with the RTC Pi Hats [https://blog.dan.drown.org/tag/stratum2/] was to have a more stable local frequency. This is useful when you can't reach your upstream
TCXO TCXO aging part 2 The previous data I have on aging [https://blog.dan.drown.org/tcxo-rtc-hats-aging-rtc-frequency/] covered 10 days, and now I want to come back to this now that more time has passed. This data
ntp TCXO RTC Hats: aging & RTC frequency I'm focusing on oscillator aging and RTC frequency in this post. See also: initial data [https://blog.dan.drown.org/tcxo-rtc-hats-initial-data/], picture [https://blog.dan.drown.org/tcxo-rtc-hats/], other stratum 2 posts [https:
ntp TCXO RTC Hats: Initial data The TCXO RTC hats [https://blog.dan.drown.org/tcxo-rtc-hats/] are collecting data. I'm focusing on the RTC part in this post. See also: other stratum 2 posts [https://blog.dan.drown.org/
ntp TCXO RTC Hats My new stratum 2 NTP server hats arrived from Macrofab today! I have a few hand soldering things to do (32khz crystal and headers), and then I can start calibrating them.
time Temperature compensation Temperature effects are usually the largest source of frequency changes in clocks. So I have three temperature sensors on my test system [https://blog.dan.drown.org/frequency-synchronization-without-phase-in-ntp/]. The sensors are: one built
time Frequency synchronization without phase in NTP I've been working on my high accuracy RTC project [https://blog.dan.drown.org/stm32f030-devboard-with-tcxo/]. Here's a picture of one of the two systems: Connections The TCXO devboard, BME280, and PCF RTC are
rtc RTC comparison Real Time Clocks I bought two high accuracy RTC (real time clock) modules and wanted to compare them. RTCs are useful for very low power clocks. They can run for years off of