Topic

ntp

A collection of 50 issues

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 all on the i2c bus. The TMP36 sensor is hidden behind a wire

GPS PPS drift when it has no signal

Question: What happens to a GPS receiver's pulse per second (PPS) when it loses signal for a long time? To answer this, I first moved the antenna away from the window and put it in an anti-static bag. I did this on the 16th at 01:02 GMT.

Binary Clock, Update 3

I've made some progress on my binary clock project Here's a video of it in its new case: https://www.youtube.com/watch?v=VnHRYwOf2ZQ I've been tweaking the clock controller code and experimenting with different setups to see how the code reacts. First

Binary Clock, update 2

This is an update on my binary clock project. Click here for the previous post [https://blog.dan.drown.org/binary-clock/] I've been working on a PID controller [https://en.wikipedia.org/wiki/PID_controller] to adjust the local clock's rate. Right now, it's

binary clock

I've been working on a clock that gets its time from the internet and has a binary display. It should use NTP to keep its clock within tens of milliseconds of true time. It should automatically adjust for daylight savings time. It should keep an estimate of the

Beaglebone Cape for NS-T, revision 2

I'm testing the second revision of this cape now. Schematic is on github [https://github.com/ddrown/NS-T-BBB-Cape] (left: rev1, right: rev2) It's working much better than rev1, but time will tell if it has the same frequency dropouts. I've also published the NTP

Update on Beaglebone Cape for Navspark NS-T

The cape [https://blog.dan.drown.org/beaglebone-cape-for-navspark-ns-t/] has been running for 5 days now. I've been tweaking the system to see if I can get it stable. So far, the local clock looks like this: The red line shows the clock offset. When things are working properly,

Beaglebone Cape for Navspark NS-T

Goal My next goal in the quest for a better NTP server is to improve the TCLKIN source. Previously, I was experimenting with TCXO's. I bought a Navspark NS-T (a timing-grade GPS receiver) and designed an adapter cape for it. This is my first time designing a circuit

TCXO + Beaglebone Black, part 2

Starting from the previous TCXO modification [https://blog.dan.drown.org/tcxo-beaglebone-black/], I wanted to get a 24MHz TCXO working. Trial #1 I bought a set of three undocumented 24MHz TCXO's off ebay for $6. I was hoping that since they were not SMD parts, they would be

TCXO + Beaglebone Black

I've added support for an external clock (TCLKIN) to the Beaglebone Black timer driver [https://blog.dan.drown.org/beaglebone-black-timer-capture-driver/]. Setup I used what I had on hand to test it. I setup a Navspark microcontroller to send a ~1MHz PWM (code here [http://dan.drown.org/bbb/