Topic

time

A collection of 19 issues

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 a coin cell battery. Both of these modules are special in they claim higher accuracy than your

stm32f030 devboard with TCXO

I'm interested in making a high accuracy real time clock (RTC). To experiment with the hardware I need for that, I created a development board based on the STM32F030F4P6 (which is a 20-TSSOP package) and a TCXO. I chose that STM32 for two reasons: one, because it'

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.

Decoding WWVB, part 2

I worked on detecting the timing information from the WWVB signal. Being able to locate the start of the second is important because it is the clock the data is encoded against. I have a few recordings of WWVB I'm testing against, and I started with the lowest

Decoding WWVB

I've been playing with decoding WWVB. I have a random wire [https://en.wikipedia.org/wiki/Random_wire_antenna] antenna connected to my sound card's line in jack. The sound card is a Realtek ALC1150 built into the motherboard and can do 192ksamples/second. I'

Navspark NTP stratum 0 clock

Project Goal I want to create a stratum 0 NTP clock that does not require soldering or any special hardware. It should only require a USB port and software. It should have at least 125 microsecond accuracy. How? I created a Navspark firmware to print a timestamp on the serial

Navspark UART/USB bridge

I created a program on the Navspark to send characters at 150 microsecond intervals and then received them on a PC. Below is a histogram of how long it took between characters: The red boxes are how long it took for the UART/USB bridge to send one character in

Navspark timer drift, #2

Second run, this time comparing the Navspark's internal CPU clock against the GPS time. Samples of both clocks are taken once per second, and the amount of time that has passed is calculated for both. The ideal CPU clock would be a perfectly horizontal line at 0.000

Navspark timer drift

The Navspark is a microcontroller with a GPS peripheral. It runs the GPS navigation/timing code as a binary-only library, and uses the Arduino IDE/environment. I have custom code printing timestamp markers on the Navspark, and I'm measuring the timestamp of the first byte of each line