Difference between revisions of "GPS Frequency Standard"
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** 3.3V, 40 MHz | ** 3.3V, 40 MHz | ||
* [[PulseGen]] modified to receive input from GPS output and drive 50 Ohm output on BNC | * [[PulseGen]] modified to receive input from GPS output and drive 50 Ohm output on BNC | ||
+ | * LED operating | ||
+ | ** Blinks on 1 for 1 sec at power up | ||
+ | ** Goes off until communication is established | ||
+ | ** Blinks intermittently as packets are received | ||
+ | ** Stay on after generator output is done | ||
* Fits into Aluminum Project Box Enclosure DIY 100*76*35mm - [https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2334524.m570.l1313&_nkw=100*76*35mm+aluminum&_sacat=0&LH_TitleDesc=0&_odkw=100*76*35mm+Aluminum+PCB+Instrument+Box+Enclosure+Electronic+Project+Case+Set&_id=174408274566 ebay search] | * Fits into Aluminum Project Box Enclosure DIY 100*76*35mm - [https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2334524.m570.l1313&_nkw=100*76*35mm+aluminum&_sacat=0&LH_TitleDesc=0&_odkw=100*76*35mm+Aluminum+PCB+Instrument+Box+Enclosure+Electronic+Project+Case+Set&_id=174408274566 ebay search] | ||
Revision as of 16:04, 26 June 2022
Contents
Build V2
Stand-alone design does not require PC
- Hard coded 10 MHz output after lock
- NEO-7M GPS
- QTPy49 card
- QT Py (SAMD based)
- Running CircuitPython
- 3.3V, 40 MHz
- PulseGen modified to receive input from GPS output and drive 50 Ohm output on BNC
- LED operating
- Blinks on 1 for 1 sec at power up
- Goes off until communication is established
- Blinks intermittently as packets are received
- Stay on after generator output is done
- Fits into Aluminum Project Box Enclosure DIY 100*76*35mm - ebay search
Wiring
# Wiring # Signal Color From To # GND Black QTPy49 J4-1 GPS pin 4 # VCC Red QTPy49 J4-2 GPS pin 5 # QTPy>GPS Blue QTPy49 J4-3 GPS pin 2 # GPS>QTPy White QTPy49 J4-4 GPS pin 3 # GND Black QTPy49 J5-1 PulseGen GND # VCC Red QTPy49 J5-2 PulseGen VCC # PPS Purple GPU pin 1 PulseGen In # LED-VCC Red QTPy49 J9-3 D0 # LED-GND Black QTPy49 J9-1 GND
Code
- GPS_004.py - Final working code
- Saved as code.py to auto-run
- GPS_003.py - Capture data from GPS module a line at a time - helpful for debugging
- GPS_002.py - Read 32 bytes at a time
- GPS_001.py - Formatted stings output
Build V1
- NEO-7M GPS
- FTDI-49MM card set to 3.3V levels
- Frequency set using ublox software on PC
- PulseGen modified to receive output from GPS and drive 50 Ohm output out of the box
- Fits into Aluminum Project Box Enclosure DIY 100*76*35mm - ebay search
GPS
- GPS Satellite Positioning Module NEO7M UBLOX
- Specifications:
- Working Voltage: 3.3v-5.0v
- Color: As Picture Shown
- Description:
- With micro USB interface, you can debug GPS module with ordinary phone data cable, no longer need to use USB-TTL and other tools.
- TTL interface is reserved to facilitate the use of USB-TTL or external microcontroller to control and receive GPS information.
- Ceramic antenna on module board, no GPS external antenna can be used to search for stars.
- Reserved SMA antenna interface, can use external antenna, star search ability is stronger.
OLED Display
Description
- OLED display, no need backlight, self-illumination.
- The display performance is better than the traditional LCD display, also lower consumption.
Specifications
- Driver IC: SSD1306
- Size: 0.91 inch OLED
- Resolution: 128 x 32
- Size: 38 * 12 mm
- Number of pins: 4 Pin
- Interface Type: IIC interface
- Display Color: White
- Operating temperature:-40 ~ 85 ℃
I2C Pin Out
- GND: Power Ground
- VCC: Power + (DC 3.3 ~5v)
- SCL: Clock Line
- SDA: Data Line
Reference Materials
- Design & Build a GPS locked Frequency Standard- Scullcom
- SIMPLE 10 MHZ GPS FREQUENCY STANDARD AND RF GENERATOR
- uses Arduino Nano as FTDI replacement
- An Arduino-based GPS Disciplined Oscillator
- An Arduino Version of Brooks Shera's GPSDO
- Simulating the Brooks Shera (W5OJM) GPSDO Algorithm
Videos