Re: [time-nuts] Lowest Power NTP Server

"Didier, I'm not sure I saw Bob write that 5uS was his goal." I realize that now, I saw 5uS in another email thread and wrongly associated the two :) Happens when doing two things at once... Anyhow, I mentioned it because I did do some experiments early on the ESP8266 and the seemingly random

Re: [time-nuts] Lowest Power NTP Server

Hi My target is “a couple of mili seconds” so a microsecond or five is sort of a non-issue. The whole thing will run over (slow) WiFi. That puts a whole other layer of delay on top of things. Holding nanoseconds or microseconds with that sort of overhead seemed to be a bit much. What I’m

Re: [time-nuts] 100 MHz decade Divider II

Send me your snail mail address and I'll send you a pcb with a 12080 attached with regulator chip etc.  Just attache power input and output leads and you have a nice  divide by 10 prescaler on a 1/2 inch by 1.5 inch pcb.  Glad to help Bob, KE6F -Original Message- From: Perry Sandeen

Re: [time-nuts] Lowest Power NTP Server

Didier, I'm not sure I saw Bob write that 5uS was his goal. I don't think anyone would claim that ordinary cheap WiFi can achieve consistent sub-millisecond variations in latency. Tim N3QE On Sun, Dec 1, 2019 at 5:06 PM Didier Juges wrote: > You should look at latency. The ESP8266 has serial

Re: [time-nuts] Lowest Power NTP Server

This article indicates: " Average precision was measured (by comparison to known-good time sources) with 1 ms, or 0.001 seconds " On Sun, Dec 1, 2019 at 2:01 PM David wrote: > I'd think one of the ESP32's would be a fine choice. They have some good > power management options to wake up

Re: [time-nuts] Lowest Power NTP Server

You should look at latency. The ESP8266 has serial (SPI) flash and a relatively small internal cache. When the chip needs to load code from flash, that can take a while, compared to the 5uS target. Great for cheap IoT stuff, not so great for time sensitive, in my opinion. On Sun, Dec 1, 2019 at

Re: [time-nuts] Lowest Power NTP Server

On 12/1/19 7:47 AM, Bob kb8tq wrote: Hi If you are going to run the beast on batteries, and talk to it via WiFi, what’s the lowest power NTP server you can build? Timing source to keep it under a few ms would have to be included. GPS seems to be a reasonable choice. Have you looked at

Re: [time-nuts] Lowest Power NTP Server

On 12/1/19 9:29 AM, Poul-Henning Kamp wrote: You can do better than RPi, since a NTP server basically only needs to understand two packets: IP/UDP at port 123 and ARP packets. There are WiFi enabled microcontrollers that could be taught how to do that, but you'd have to write up your

Re: [time-nuts] Lowest Power NTP Server

I'd think one of the ESP32's would be a fine choice. They have some good power management options to wake up periodically to do the work, making for even lower power consumption. Looks like someone has already written some code that could be adapted?

Re: [time-nuts] Lowest Power NTP Server

Hi Digging into this: https://kb.meinbergglobal.com/kb/time_sync/ntp/configuration/ntp_broadcast_mode and the “deep sleep” power savings modes on the ESP32, it appears that one *could* do a once a minute / hour

Re: [time-nuts] Lowest Power NTP Server

Hi I guess one *could* claim that this: https://github.com/DennisSc/PPS-ntp-server Sort of eliminates my “to lazy to code it up from scratch” issue ….. So, the ESP’s seem to be in the 50 to 70 ma range depending on which one you look at. The GPS

Re: [time-nuts] Lowest Power NTP Server

Hi So something like one of the many ESP32 based boards? Of course when it comes to the “code from scratch” part there is the problem that I’m pretty (most would say very …) lazy :) :) :) Bob > On Dec 1, 2019, at 12:29 PM, Poul-Henning Kamp wrote: > > > > You can do better than

Re: [time-nuts] Lowest Power NTP Server

ESP8266 as a simple UDP server is 50mA * 3.3V = 0.17W. Tim N3QE On Sun, Dec 1, 2019 at 12:22 PM Bob kb8tq wrote: > Hi > > If you are going to run the beast on batteries, and talk to it via WiFi, > what’s the lowest power > NTP server you can build? Timing source to keep it under a few ms would

Re: [time-nuts] Lowest Power NTP Server

You can do better than RPi, since a NTP server basically only needs to understand two packets: IP/UDP at port 123 and ARP packets. There are WiFi enabled microcontrollers that could be taught how to do that, but you'd have to write up your NTP daemon from scratch which is not hard when

[time-nuts] Lowest Power NTP Server

Hi If you are going to run the beast on batteries, and talk to it via WiFi, what’s the lowest power NTP server you can build? Timing source to keep it under a few ms would have to be included. GPS seems to be a reasonable choice. So far this seems to be the leading contender:

Re: [time-nuts] 100 MHz decade Divider II

Hi Indeed the filtering / noise shaping aspect of these devices is what ultimately drove them off of most test benches. That was still taking place on a few benches back in the early 70’s (when I first started doing this stuff …). There were still enough of them running around that it was

Re: [time-nuts] 100 MHz decade Divider II

In my opinion, those PLLs should be made unusually fast to have a fast response from input to output. There is also the EFC low pass response of the OCXOs. On Sun, Dec 1, 2019 at 7:01 AM Perry Sandeen via time-nuts wrote: > > Yo Bubba Dudes!, > Thanks to all who replied. > Gerhard, besides