amescon RasPiComm User manual

User Manual
Extension board for the Raspberry Pi single-board computer
Main Features
•RS-485 port – for control over stepper motors, etc.
•RS-232 port – connect to serial port devices like a modem or your PC
•I2C connector – directly connect a display or sensors
•real-time clock with battery backup
•5-way joystick
•piggyback mounting – no cables or additional space required
•driver support and sample applications code
•fully assembled including the backup-battery

User Manual
amescon 2
Table of Contents
1. Technical Specifications................................................................................................................... 2
2. Technical Drawing ........................................................................................................................... 3
3. First Time Installation ...................................................................................................................... 4
3.1. Choice of distribution .............................................................................................................. 4
3.2. Find out your Raspberry Pi's revision ...................................................................................... 4
3.3. Raspicomm Setup.................................................................................................................... 5
3.4. Setup-Script Parameters ......................................................................................................... 5
4. Using your Raspicomm.................................................................................................................... 5
4.1. RS-485 Port.............................................................................................................................. 5
4.2. Serial Port / RS-232.................................................................................................................. 6
4.3. Joystick .................................................................................................................................... 6
4.4. Outputs (LEDs)......................................................................................................................... 6
4.5. HWClock .................................................................................................................................. 7
5. Additional Links ............................................................................................................................... 7
1. Technical Specifications
Size: 35,2 x 56mm
•RS-485
oup to 230.400 baud
opluggable screw terminal
connector (A, B, GND)
•RS-232
oNo hardware handshake
oup to 115.200 baud
opluggable screw terminal
connector (RX, TX, GND)
•Real Time Clock
oCR2032 RTC backup battery
included
opowers the clock for approximately
10 years
•5 Inputs
oconnected to onboard joystick (4
way + push)
o5V tolerant
o2mm pitch external connector, not
populated
•2 Outputs
o5V, 100mA max. each
o5V relays can be connected without
additional circuitry due to onboard
protection diodes
o2mm pitch connector, not populated
•SPI Connector
o2mm pitch connector, not populated
•2 I2C Connectors
•Power Connector
opluggable screw terminal connector
(+, -)
oeither powers the Raspberry Pi and
RasPiComm (5V, 1.5A max)
oor is a power output when powered
over USB
•RasPiComm Power Consumption
omax . 10mA (outputs off)
omax. 210mA (outputs on and
maximum rating drawn)

User Manual
amescon 3
2. Technical Drawing

User Manual
amescon 4
3. First Time Installation
3.1. Choice of distribution
Install a distribution that supports i2c and the spi bus.
1. Download Distribution:
oeither Raspbian 3.6.11+ (2013-07-26)
oor Raspbian 3.6.11+ (2013-05-25)
oor Raspbian 3.6.11+ (2013-02-09)
oor Raspbian 3.2.27+ (2012-12-15)
2. Save it to the SD card
You can find further instructions for setting up your SD-Card here.
3. Boot Raspberry Pi from the SD card
4. Configure your distribution on first boot
To reconfigure your distribution later you can always use the following command:
raspi-config
3.2. Find out your Raspberry Pi's revision
Revision 1 looks like this:
Raspberry Pi rev1 (Source: wikimedia.org)
Revision 2 can be identified by the mounting hole on the top right corner.
Raspberry Pi rev2 (Source: raspberrypi.org)

User Manual
amescon 5
3.3. Raspicomm Setup
Execute the setup-script from your home directory (cd ~)
wget http://downloads.amescon.com/rpc_setup.sh && chmod +x ./rpc_setup.sh && sudo ./rpc_setup.sh
The setup-script requires the following actions:
•Choose revision according to your Raspberry Pi (switch revisions with the 'c'-button)
•Activate installation script (with the 'i'-button)
This script will install i2c-tools and permanently set up the following devices:
oJoystick
oRS-485
oRS-232
oOutput (LEDs)
oHWClock
•Confirm driver installation with 'y'.
•For the RS-232 to work, you'll need to restart your Raspberry Pi. All other devices are ready
to go without a restart.
3.4. Setup-Script Parameters
The script can be run with parameters that are however not needed for a routine setup. For a full list
of parameters please use one of the following commands:
./rpc_setup.sh /?
./rpc_setup.sh --h
./rpc_setup.sh --help
While the help-parameters do not need root access, most others will. For example, the superuser-
elevated command
sudo ./rpc.setup.sh --remove-autostart
will remove the autostart-sequence for your Raspicomm.
4. Using your Raspicomm
4.1. RS-485 Port
After the device driver is installed, the RS-485 port is added under this name:
/dev/ttyRPC0
You can use linux standard libraries to access the port.
Example code for C or C++:
int fd = open("/dev/ttyRPC0", O_RDWR | O_NOCTTY | O_NDELAY); ...
More code examples can be found here: Sample Applications.

User Manual
amescon 6
4.2. Serial Port / RS-232
By default the RS-232 port is used by the Raspberry Pi's startup routine and needs to be reconfigured
for use. The setup script does so automatically. Please note that a restart is required, after which you
can use standard libraries to access the serial port. The device name is:
/dev/ttyAMA0
Example code for C or C++:
int fd = open("/dev/ttyAMA0", O_RDWR | O_NOCTTY | O_NDELAY); ...
Our Sample Applications can be adapted for use with the RS-232 port by replacing the RS-485 name
/dev/ttyRPC0 by its RS-232 counterpart /dev/ttyAMA0.
4.3. Joystick
The joystick is mapped to the following GPIOs:
1. 4 = right side (towards HDMI)
2. 22 = push
3. 23 = bottom side (towards power connection)
4. 24 = left side (towards audio out)
5. 25 = top side(towards usb)
You can use linux standard libraries to access the joystick in the same way as the serial port.
Example code for C or C++:
int fd = open("/sys/class/gpio/gpio22/value", O_RDONLY); ...
4.4. Outputs (LEDs)
The Output is mapped to the following GPIOs:
•Output 1 (D1): GPIO 18
•Output 2 (D2): GPIO 21 (Raspberry Pi rev.1) or GPIO 27 (Raspberry Pi rev.2)

User Manual
amescon 7
4.5. HWClock
The setup-script will synchronize your system time with the HWClock every time your Raspberry Pi is
restarted.
This command will synchronize your HWClock with the system time:
sudo hwclock --systohc
This command will manually synchronize your system time with the HWclock:
sudo hwclock --hctosys
To manually set your HWClock, use the following command:
sudo hwclock --set --date='mm/dd/yy hh:mm:ss' –localtime
5. Additional Links
Should you require further information or are looking for project code, check out the following links:
•Raspicomm F.A.Q: Answers to the most common questions.
•Amescon Github: Our open-source sample applications for your Raspicomm.
•Raspicomm Support Forum: If the manual and F.A.Q could not answer your questions, this is
the place to go.
•Online-Version of this manual