Janz Tec emVIEW-7/RPI3, Hardware Manual, Page: 28 / 34

6 - 26 emVIEW-7/RPI3 ( Hardware and Software Manual )
•
Programming Information
©
Janz Tec AG Rev. 1.0
6.4 CAN
The CAN controller is clocked by a 16 MHz crystal.
6.5 Serial Port (RS232/RS485)
The UART is clocked by a 1.8432 MHz oscillator.
When in RS485 mode, the transmitter is controlled by the UART’s RTS signal. A low enables the
transmitter.
The receiver is disabled whenever the transmitter is enabled, hence transmitted characters are not
received. It is possible to modify the hardware such that the receiver is always enabled, to allow
verification of transmitted characters. Ask for details if you need to make such a modification.
6.6 Digital IO
The digital inputs and outputs are controlled by Raspberry PI GPIO signals.
IO GPIO
DI1 GPIO6 (Pin 31)
DI2 GPIO13 (Pin 33)
DI3 GPIO16 (Pin 36)
DI4 GPIO19 (Pin 35)
DO1 GPIO23 (Pin16)
DO2 GPIO22 (Pin 15)
DO3 GPIO27 (Pin 13)
DO4 GPIO18 (Pin 12)
To turn digital output on (drive VIO to the output), set the GPIO to high state. All other states (low,
high-Z or weak pullup) will turn the digital output off.
Digital input GPIOs must be configured as input. A high level will be detected if sufficient voltage is
detected on the digital input pin.
Programming the digital inputs and outputs is the same as on a standard Raspberry PI 2 B, so you
can get more information on
http://elinux.org/RPi_Low-level_peripherals#Shell
6.7 Console RS232
On Raspbian based installations, by default this port is configured as a serial Linux console and you
can log into the Raspberry using a standard serial (null modem) cable and a terminal program like
“Putty”. Use the following settings to log in: Speed (baud rate): 115200, Bits: 8, Parity: None, Stop
Bits: 1, Flow Control: None
To permanently disable the serial console and use this port for RS232 (2 wire) connections with the
device name /
dev / ttyAMA0
, the tool “raspi-config" allows the configuration in menu, 8 Advanced
Options, A7 Serial and “No”. (if you need 4-wire RS232, use the RS232/RS485 port, see 3.2.5)
6.8 Overclocking
The thermal design of the emVIEW-7/RPI3 does not support CPU overclocking. Changing the CPU
parameters (CPU MHz, Voltage) is not recommended as it will permanently set a fuse in your SoC and
void your warranty.