Compatibility
I've tested this shield to create an NTP server with both Raspberry Pi 1 Model B and 2 Model B, both of them work like a charm, and should work with any board that uses the original Pi's 26-pin mapping. The other connected pins are not yet tested.

Should work with all normal-size NavSpark variants, NavSpark (GPS), NavSpark-GL (GPS/GLONASS), NavSpark-BD (GPS/Beidou).
Pinout

| Raspberry Pi pin | NavSpark pin |
| GPIO 22 | 1PPS |
| GPIO 4 | TRIG |
| GPIO 17 | GPIO 12 |
| GPIO 18 | GPIO 13 |
| GPIO 27 | GPIO 14 |
| GPIO 23 | GPIO 16 |
| GPIO 24 | GPIO 20 |
| RX0 | TX1 |
| I2C | I2C |
| SPI (CE0) | SPI |


Gergely Imreh