103696
Contents
103696 - Serial GPS Adapter Board with Synchro Input
Description
103696 is an adapter board used with the 10369 interface board to connect NMEA 0183 serial GPS devices to the Elphel Model 353 camera.
Adapter provides 3.3V/5.0V (jumper selectable) power to the GPS device, communicates with it over RS-232 (+/-5V) TxD/RxD lines and uses optional synchronization pulse (usually 1pps) from the device. It includes USB-to-Seraial converter chip that allows full communication with the GPS device using the camera software, additionally the RxD signal is fed to the camera FPGA, decoded and logged in the camera sytem memory buffer - together with the optional IMU data, each message with the microsecond resolution timestamp. The source of the timestamp even is selectable among synchronization pulse from the GPS (either polarity), the start bit of the first NMEA sentence afther the pause or the start of each individual NMEA sentence. Current FPGA code allows programming of up to 4 different NMEA sentences that are recognized, decoded and logged.
Connectors
The board uses two alternative connectors to the GPS device:
- standard (with extra connections for GPS power and synchro pulse) for RS-232 9-pin DSUB (male) or
- 8-pin low profile Hirose connector
First option is used when the board is mounted on the camera body and the connector extends outside for the external GPS, the second - when the GPS is mounted inside the camera body. In that case the DSUB mounting holes are used to mount the 103696 adapter board.
J1 - to the 10369 board
| Pin | Signal | Notes |
|---|---|---|
| 1 | VP33IN | +3.3V power input |
| 2 | IPULSE1SEC | GPS synchro pulse to FPGA, output |
| 3 | IRXD | GPS data line converted to TTL levels for FPGA, output |
| 4 | SDA | i2c SDA |
| 5 | SCL | i2c SCL |
| 6 | GND | ground |
| 7 | VP5IN | USB +5V power |
| 8 | DM | USB data - |
| 9 | DP | USB data + |
| 10 | GND | ground |
J2 - DSUB-9 (male) for external GPS connection
| Pin | Signal | Notes |
|---|---|---|
| 1 | PULSE1SEC | GPS synchro pulse (non-standard for RS-232), input |
| 2 | RXD | Serial data signal from the GPS, input |
| 3 | TXD | Serial data signal to the GPS, output |
| 4 | GPSPWR | GPS 3.3V power (non-standard for RS-232), output (may be changed to 5.0V on the 103696 board) |
| 5 | GND | ground |
| 6 | DSR | unused, connected to wirepad W1 |
| 7 | RTS | RS-232 RTS signal, output |
| 8 | CTS | RS-232 CTS signal, input |
| 9 | RI | unused, connected to wirepad W2 |
J3 - Internal connector for the GPS
| Pin | Signal | Notes |
|---|---|---|
| 1 | PULSE1SEC | GPS synchro pulse (non-standard for RS-232), input |
| 2 | RXD | Serial data signal from the GPS, input |
| 3 | TXD | Serial data signal to the GPS, output |
| 4 | GPSPWR | GPS 3.3V power (non-standard for RS-232), output (may be changed to 5.0V on the PCB) |
| 5 | GND | ground |
| 6 | GP1 | unused, connected to wirepad W3 |
| 7 | RTS | RS-232 RTS signal, output |
| 8 | CTS | RS-232 CTS signal, input |
J4 - Auxiliary GPS Power
| Pin | Signal | Notes |
|---|---|---|
| 1 | GPSPWR | optional external power for the GPS device |
| 2 | GND | ground |
Set 3.3V or 5V power to the GPS receiver
The power voltage level is set with JP4 and JP5 jumpers.
| Power | JP4 | JP5 | |||
|---|---|---|---|---|---|
| 3.3V | disconnected | connected | 5V | connected | disconnected |
