blinky

Blinking lights to tell time. And it beeps.

Build and flash

Build with:

mkdir build ; cd build ; cmake .. ; make

Note when programming the GPS board, the GPS must be unplugged while programming.

Program flash using stlink with:

st-flash --reset --format ihex write build/blinky.hex

Can program using Stm32CubeProgrammer with RTS=1, DTR=0, baud at 115200, Parity Even, data bits 8, stop bits 1, flow control off.

Program flash using USB serial with:

stm32flash -w build/blinky.hex -v -b 115200 -m 8e1 -i "-dtr," /dev/cu.usbserial-31110

If this fails, try the following reset then try to flash again. This will not work on a brand new uninitialized board, the board needs to be programmed for the first time with st-flash.

Can reset the board with:

stty -f /dev/cu.usbserial-31110 hup

Monitor output connect with Serial program. Use 115200 baud with 8 bits, no parity, 1 stop bit. Set the RTS and DTR both low. Screen fails to do this. It sets RTS and DTR both high it will not work.

To use python miniterm (replace usbserial-31110 with number on your machine):

pyserial-miniterm -e --parity N --rts 0 --dtr 0 /dev/cu.usbserial-31110 115200

Can exit the miniterm with CTRL+]. This will cause board reset when it starts.

Tools and Dependencies

Set up a mac to be able to build by installing:

TODO
pip3 install pyserial

Features

Blink Timing Board

On the Rev A hardware 1.0 software have:

Timing board with TXCO, LTC Sync in, LTC Sync out, LED grid, battery power, USB debug, audio in/out
Display 120 fps tick on 10x4 grid
3.3V LTC Sync Out
PPS out is hold sync button while booting
Jitter of less than 1 ms
Jam sync to 3.3V Sync input
Time drift of < 5 ms in 1 hour
USB port for serial data
read calibration from EEPROM
audio out of beep
headset monitor of audio out
usb upgrade of firmware
Status LEDs: error(red), external synced (green), not sync ( blue ), have sync (teal)
audio input to detect beep
battery with 2h life and USB charger

Clock and GPS Board

On the Rev A hardware 0.2 software have:

GPS board with GPS, OCXO
LTC sync out, LTC sync in
Does not have audio or led display grid
10 MHz sine wave output 1V p2p into 50 ohm, 3 channels
Sync to GPS PPS
Show current PPS offset from GPS PPS
Compare PPS accuracy to GPS over 24 hours
read calibration from EEPROM
USB serial display of: Time, GPS Error, SyncIn Error
Aux input of 10 MHz signal to compare
PPS jitter of about +/- 20 ns and error less than 10 ns
USB upgrade of firmware
USB 3A power for gps board
USB output serial data for computer time sync

Light GPS Board