GPIO.txt - GPIO Notes for Rivendell

GPIO Notes for Rivendell

Rivendell supports the following General Purpose Input/Output (GPIO) devices:

Gameport Joystick Buttons

USB Joystick Buttons

Measurement Computing PCI-PDIS08 Board (Only in systems with old Kernels)

Measurement Computing PCI-PDIS16 Board (Only in systems with old Kernels)

Measurement Computing PCI-DIO24 Board (Only in systems with old Kernels)

Several supported switcher devices feature GPIO capabiities as well, see the file SWITCHERS.txt for more info.

JOYSTICK DEVICES

Joystick support utilizes the Linux Input Device subsystem. Inputs are active-low, and should be wired as follows:

02: Input 1
04: Ground

07: Input 2
05: Ground

10: Input 3
12: Ground

14: Input 4
12: Ground

In addition, you will need to connect 47 kohm resistors between the following pins: 1-3, 6-8, 9-11 and 13-15. While not strictly needed for the GPI portion of the interface to work, the kernel's analog joystick driver will refuse to initialize the port if these resistors (or a real joystick) are not present.

The device name of the joystick will be one of the /dev/input/event<n> devices.

NOTE: There have been reports that some port models do not internally connect pin 12 to ground. The symptom of this situation will be that Inputs 1 and 2 work, but not Inputs 3 and 4. If this is the case, connecting the ground for Inputs 3 and 4 to pins 04 or 05 should remedy the problem.

MEASUREMENT COMPUTER GPIO BOARDS

To configure one of the supported Measurement Computing GPIO boards, proceed as follows:

1) Install the card(s) in the computer. In the case of the PCI-DIO24,two cards may be necessary, as each seperate card is entirely utilized as either inputs or outputs.

2) Test it out. Two programs exist for this purpose: gpitest tests GPI inputs, and gpotest tests GPO outputs. These programs come with the 'libradio' package. NB There is now one program rdgpimon.

3) Define a GPIO device in RDAdmin->Stations->Switcher/GPIO. Use a device type of Local GPIO.

---

==GPIO BOARD-SPECIFIC NOTES== (NB These only work with old Kernels)

The Measurement Computing PCI-PDIS08 and PCI-PDIS16 boards feature floating, opto-isolated inputs. The inputs are not polarity sensitive and may be driven by either AC or DC. The outputs are electro-mechanical relays with dry contacts. Connector pinouts are as follows:

PCI-PDIS16 -- DB37 Male Connector (using C50F-37F Cable)

Pin  Signal
----------------
  1  Input 8/16
 20  Input 8/16

  2  Input 7/15
 21  Input 7/15

  3  Input 6/14
 22  Input 6/14

  4  Input 5/13
 23  Input 5/13

  5  Input 4/12
 24  Input 4/12

  6  Input 3/11
 25  Input 3/11

  7  Input 2/10
 26  Input 2/10

  8  Input 1/9
 27  Input 1/9

  9  Output 8/16 C
 28  Output 8/16 N/O

 10  Output 7/15 C
 29  Output 7/15 N/O

 11  Output 6/14 C
 30  Output 6/14 N/O

 12  Output 5/13 N/C
 13  Output 5/13 N/O
 31  Output 5/13 C

 14  Output 4/12 C
 32  Output 4/12 N/C
 33  Output 4/12 N/O

 15  Output 3/11 N/C
 16  Output 3/11 N/O
 34  Output 3/11 C

 17  Output 2/10 C
 35  Output 2/10 N/C
 36  Output 2/10 N/O

 18  Output 1/9 N/C
 19  Output 1/9 N/O

 37  Output 1/9 C
----------------------
C = Common
N/O = Normally Open
N/C = Normally Closed

---

The Measurement Computing PCI-DIO24 board features TTL logic-level connections, which can be configured to operate either as inputs or outputs. Connector pinouts are as follows:

PCI-DIO24 -- DB37 Male Connector

Pin  Signal
---------------------
 37  Input/Output 1
 36  Input/Output 2
 35  Input/Output 3
 34  Input/Output 4
 33  Input/Output 5
 32  Input/Output 6
 31  Input/Output 7
 30  Input/Output 8
 10  Input/Output 9
  9  Input/Output 10
  8  Input/Output 11
  7  Input/Output 12
  6  Input/Output 13
  5  Input/Output 14
  4  Input/Output 15
  3  Input/Output 16
 29  Input/Output 17
 28  Input/Output 18
 27  Input/Output 19
 26  Input/Output 20
 25  Input/Output 21
 24  Input/Output 22
 23  Input/Output 23
 22  Input/Output 24

 11  Ground
 13  Ground
 15  Ground
 17  Ground
 19  Ground
 21  Ground

 18  +5 VDC
 20  +5 VDC

 16  +12 VDC

 14  -12 VDC

WARNING: The +5 VDC, +12 VDC and -12 VDC pins are connected directly to the power supply buss of the host PC. Improper use of these pins can cause serious damage to your computer!

Other GPIO wiki pages

RDGpiMon - GUI Utility Program for monitoring GPI and GPO status

Troubleshooting GPIs and GPOs from the command line