126 lines
6.9 KiB
Markdown
126 lines
6.9 KiB
Markdown
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## for sure upgrades:
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1. UPGRADE TO PI5 8GB
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1. HARDWARE IMPROVEMENTS
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1. the Pi5 8GB
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2. Case
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1. Metal
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2. Quality
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3. Actively Cooled (fan)
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4. Exposes ALL GPIO and usb
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3. Nice quality 256GB microsd (Sandisk Extreme 256GB)
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4. New long high grade ethernet cable
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2. SOFTWARE IMPROVEMENTS
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1. OPERATING SYSTEM IMPROVEMENTS
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1. Rpi os lite 64bit latest stable
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2. disable and uninstall any unused services
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1. get list of registered services with
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```bash
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sudo service --status-all | tee -a "~/$(date +"%Y-%m-%d-%H%M-%S-%Z")_service-status-all.txt"
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```
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1. uninstall any unused packages
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1. get list of packages installed with
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```bash
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sudo apt list --installed | tee -a "~/$(date +"%Y-%m-%d-%H%M-%S-%Z")_installed_packages.txt"
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```
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1. pin chrony/etc to one specific core?
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2. dial up NEO-10 gps timekeeping uart speed to highest practical baud rate
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1. to Pi5 GPIO
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2. to Ublox2 highest stable setting
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1. This will require serial interface with the chip
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1. normal pins for uart?
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2. usb d+ and d- lines?
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3. external uart to somewhere else
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3. OUTPUT IMPROVEMENTS
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1. remote hosted web apps (prolly node) that get goverened by grandfather clock over idk webrtc/websockets/mqtt/calling a page, whatever
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1. goven universal beat time web app
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2. govern a normal multi-tz grandmasterclock output web app
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2. highest possible accuracy/speed ntp/time server available
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3. Update Telegraf/Grafana/etc to log
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1. pps variance over four periods of time
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1. measure each pps, log exact value in telegraf->grafana
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2. Occasinoally calculate an average inaccuracy
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1. Hourly (display in grafana view)
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2. Daily (display in grafana view)
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3. Weekly (display in grafana view)****
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4. Monthly (display in grafana view)
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3. use average inaccuracy to develop multiplier/divisor in real time for chrony
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2. cpu speed variance
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1. Occasinoally calculate an average inaccuracy
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1. Hourly (display in grafana view)
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2. Daily (display in grafana view)
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3. Weekly (display in grafana view)
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4. Monthly (display in grafana view)
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2. use average inaccuracy to develop multiplier/divisor in real time
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3. checks against RTC
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1. Occasinoally calculate an average inaccuracy
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1. Hourly (display in grafana view)
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2. Daily (display in grafana view)
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3. Weekly (display in grafana view)
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4. Monthly (display in grafana view)
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2. use average inaccuracy to develop multiplier/divisor in real time
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4. checks against NTP burst
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1. Occasinoally calculate an average inaccuracy
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1. Hourly (display in grafana view)
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2. Daily (display in grafana view)
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3. Weekly (display in grafana view)
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4. Monthly (display in grafana view)
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2. use average inaccuracy to develop multiplier/divisor in real time
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1. GPS MODULE TIMEKEEPING
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1. new NEO-10 gps timekeeping one, one with a 3.3v battery input for hot/warm starts maybe the [139Euro NEO-F10T L1/L5/E5a Receiver](https://gnss.store/products/elt0184)* MAKE SURE YOUR ANTENNA PLUG MATCHES THIS FORMAT! NO SCREW ON MORE LIKE SMA attached
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2. maybe get the canonical antenna/cable/adaptors off same site:
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1. (? not sure this is any better than my existing barrel antenna) [gps antenna](https://gnss.store/products/elt0140)
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2. (need) [gps antenna adaptor](https://gnss.store/products/elt0179)
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3. solder 3.3v lithium coincell battery/breakout to timekeeping gps (see datasheet)
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1. for hot and warm starts when power is lost
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2. to prevent pwoer loss of precision or accuracy
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4. see datasheet
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2. PCB HAT
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1. featuring
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1. pps gpio pin input (from NEO-10 gps timekeeping)
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2. 10mhz reference clock gpio pin input
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3. UART gpio pins in/out (from NEO-10 gps timekeeping)
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4. i2c pins for high precision RTC module
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1. and 3.3v lithium coin batt
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2. with NEO-10 gps module attached
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1. room for 3.3v lithium coin batt on NEO-10 gps timekeeping
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2. room for external antenna
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3. (?) clock generator chips (Texas Instruments LMK04832 or Analog Devices ADF4351) plus programming figured out
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1. these can take 10mhz/etc as input then multiply or divide the signal into a clean jitter free signal modified frequency output
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3. HIGH PRECISION REFERENCE OSCILLATOR SHIT ([gps disciplined 10mhz rubidium reference oscillator](https://www.aliexpress.us/item/3256811412964525.html))
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1. options for adding external oscillator:
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1. desolder pi4's normal crystal and input 10mhz reference pulses after high precision multiplying/dividing to the expected value, then soldered in. high precision pi native clock
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1. crystal available internetally
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2. would make pi4s ops far more consistant speed
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3. no effect on pps accuracy
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2. desolder gps timekeeping crystal and wire in 10mhz reference through high precision frequency multiplier/divider and soldered in
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1. this will make the gps pps very very accurate
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2. will let pi4 just operate off of the high quality pps signal
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3. apply 10mhz reference clock to rpi x xtal 0,1 to get 10mhz signal inside pi (see pi4 datasheet/notes)
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1. recalibrate chrony/gpsd/etc to base time off of this input
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1. may require custom forks or other shenanigans
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4. use high precision frequency multiplier/divider to get `10mhz reference into useable frequency for timekeeping, then input via x xtal 0,1 (see pi4 datasheet/notes)
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1. then base chrony/gpsd/etc off of that clock
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2. clock pulse generator? https://www.adafruit.com/product/2045
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1. uses i2c and an internal precision ox to generate up to three clock signals
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2. no clock input?
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3. convert 10mhz ref clock into 54mhz clock for rpi4 and rpi5
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1. Texas Instruments LMK04832 or Analog Devices ADF4351 programmed with a 5.4 frequency multiplier to convert 10mhz to 54mhz for rpi4+5 clock
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4. PULSAR SHIT
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1. will need to use google starmap thing to identify the roughs of where the milisecond pulsars are
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2. 2+ RTL-SDR V4 s
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3. 2+ LNA (Low Noise Amplifiers)
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1. coax in and out
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2. low noise < 0.5db
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3. high gain > 20db
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4. BPF (Bandpass Filter) to block strong out of band sdignasls
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5. parabolic antennas (ali express)
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1. high gain
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2. 2.5-3 meter diamater
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3. tuned to 420–440 MHz (70cm band) and/or 1420 MHz (21cm band).
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6. wire to connect to RTL-SDR 4
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7. tripod/mount/adjustment mount (look into)
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8. maybe extra usb space |