Surveyor SRV-1 /SVS
                        S-32 Expansion Bus Signals


Pin      BFin Signal        Description of Expansion Board Signal 
                                     (as supported in SRV-1 / SVS Firmware)
===      ===========       =====================================================

1        3.3V               3.3V voltage regulator 
2        GND                ground 
3        TX0                Matchport RX1 (pin 9) 
4        RX0                Matchport TX1 (pin 5) 
5        TX1/TMR6           2nd UART TX or timer 6 pwm/ppm
6        RX1/TMR7           2nd UART RX or timer 7 pwm/ppm
7        TMR2               h-bridge CE1 (pin 2)  - L motor/servo pwm/ppm
8        TMR3               h-bridge CE2 (pin 13) - R motor/servo pwm/ppm
9        SPI_MOSI        
10       SPI_MISO        
11       SPI_SCK                
12       SPI_SEL            spi_ssel3 / spi_slave (set by jumper on CPU card)    
13       SPI_SEL2        
14       I2C SCL            i2c scl    
15       I2C SDA            i2c sda
16       GND                ground
17       GPIO-H0            serial flow ctrl in - Matchport RTS1 (pin 7) ***
18       GPIO-H1            ultrasonic module trigger (out)
19       GPIO-H2            battery low-voltage detect (bat < 6V == hi)
20       GPIO-H3            master/slave processor detect (master == low)
21       GPIO-H4            h-bridge IN1 (pin 6) - L motor direction
22       GPIO-H5            h-bridge IN2 (pin 9) - R motor direction
23       GPIO-H6            serial flow ctrl out - Matchport CTS1 (pin 11) ***
24       GPIO-H7            laser 1 (transistor switch)
25       GPIO-H8            microSD SPI select on RCM board; stereo sync for SVS
26       GPIO-H9            laser 2 (transistor switch)
27       GPIO-H10           ultrasonic module #1 input
28       GPIO-H11           ultrasonic module #2 input    
29       GPIO-H12           ultrasonic module #3 input
30       GPIO-H13           ultrasonic module #4 input
31       GPIO-H14           optical encoder input (left) / soft UART TX             
32       GPIO-H15           optical encoder input (right) / soft UART RX

*** Note that SRV-1 firmware checks the hardware flow control state on pin 17 (GPIO-H0) when transmitting from UART0.  To override flow control, connect pin 17 to Ground (e.g. pin 16)