The Raspberry Pi GPIB Shield
Overview
Connecting {GPIB, IEEE-488, HP-IP, IEC-625}-capable lab equipment to your PC nowadays is mostly
a choice between several USB-to-GPIB adapters. If your platform of choice is linux, especially the Raspberry Pi,
then you may run into trouble getting some of the proprietary adapters up and running.
The Raspberry Pi GPIB Shield is an inexpensive, easily built adapter to connect and control
your GPIB-capable device using the open source
linux-gpib software.
Circuit description
As the gpib-protocol uses a simple parallel bus with open collector outputs for control signals,
the gpio-port of any Raspberry Pi is able to generate a gpib transmission. The simplest form of the adapter deploys
just series resistors, but is limited to a single device. Using driver ics (SN75160/161) a classical
measurement device bus can be formed.
Software: GPIO driver for linux-gpib
As of version 4.3.4 of linux-gpib, the driver developed here has been integrated as "gpib_bitbang". While in version 4.3.4 a beta
version for the passive adapter is included, the next release will support the SN7516x drivers through the kernel module parameter (more infos here).
The development version of gpib_bitbang.c can be found here
My thanks go to Marcello Carla and Dave Penkler who helped develop and integrate the driver and
special thanks go to Frank Mori Hess, creator of linux-gpib without whom all of this would not be possible.
Documentation
After calling 'gpib_config' the config file '/etc/gpib.conf' is parsed, the appropriate drivers (as identified by
'board_type') loaded and devices created (e.g. '/dev/gpib0'). The user then has full access over pyvisa, the python gpib bindings or
simple terminal communication via 'ibterm'.
For a more thorough introduction you can take a look into my bachelors thesis in german
or on the drivers github page.
Step-by-step instructions can be found here
NOTE: this board is incapable of device mode due to timing restrictions that can not be satisfied by a raspberry pi
RasPi GPIB Board
The RasPi GPIB Board has two variants:
- a simple (passive) adapter with series resistors for connections of single instruments
- a board fitted with driver ics (SN75160/161) to form a proper GPIB bus
For PCBs, kits or preassembled adapters, please contact us at elektronomikon@gmail.com
Currently the following options are on offer:
- PCB only: 10€
- Full kit with drivers: 35€
- Preassembled incl. testing: 75€
Note: A Raspberry Pi 2..4 is needed as the layout of the gpio port on the Raspberry Pi 1 differs.
RasPiZero GPIB Board
The RasPiZero GPIB Board is a stripped down version without driver ics and a mounting bracket to form a mechanically stable unit.
Please see the RasPiZero GPIB Board github page for the 3D-printable mounting bracket
The PCBs and mounting brackets are available soon, please contact us if you are interested