BASS board
RS-232 interface using DB9 connector of BASS
- You can connect it to a PC COM port using a straight-through cable.
- Make sure the cable you're using is not a null-modem cable (wires crossed Tx/Rx and RTS/CTS)
- If all you have is a null-modem cable, add another null modem to uncross the wires
- The DB9 on BASS is wired as a DCE. Your board should be wired as a DTE.
- DSR is an output from the DCE and an input to the DTE.
- We always assert DSR - this means we're always ready.
- It doesn't matter whether or not you assert DTR, because we ignore it.
RS-232 interface using J7 connector
- Host TX should drive pin 9 (Barracuda RX).
- Host nRTS should drive pin 5 (Barracuda nCTS).
- Pin 7 (Barracuda TX) should drive the host RX.
- Pin 8 (Barracuda nRTS) should drive the host nCTS.
- You need to supply 3.3V power on pin 23.
- your board's I/O voltage on pin 24.
- Pin 18 must be grounded to select the UART interface.
- SYNC, ANT_SW, and NRESET may be left unconnected.
- EXT_POWERON may be left unconnected until you need to do put the board in standby mode; The board goes to fully operational mode by default - shorting this pin to GND will put it into low-power standby mode; It has a pullup to MAIN POWER, so it's best to use an open-collector driver.
- The USB cable should not be plugged in when you're using J7.
Ribbon cable attached to J7
The brown wire is pin 1 - it goes on the end close to J3. The cable we use is Samtec IDSD-12-D-06.00, but any 24-pin. .1" wire-to-board connector will do.
Ribbon cable attached to J7