2.3 KiB
MDB2Pi HAT
The MDB2Pi HAT can serve as a MDB master or as a peripheral MDB Device for Vending Machines (VMC). It takes care of the MDB specific 9-bit format, electrical and timing constraints. It forwards the MDB payload to the Raspberry Pi UART using a simple serial protocol. The MDB2Pi HAT is powered from the MDB bus (10...42V regulated or unregulated supply) and backpowers the Raspberry Pi with up to 2.5A at 5V. Thus no separate power supply is required for the pi. Furthermore, the MDB2Pi HAT contains a Real Time Clock (RTC), buffered by a super capacitor.
A housing for the MDB2Pi HAT is available under http://www.thingiverse.com/thing:2209661
Configuration
Enable UART and RTC by adding the following lines to /boot/config.txt:
enable_uart=1
dtoverlay=i2c-rtc,pcf8563
disable serial console output:
sudo nano /boot/cmdline.txt
--> remove the "console=..." parameter
MDB Master and Cashless Device Demo:
Install mono runtime:
sudo apt-get install mono-runtime
Get the Demo code:
wget https://secure.abrantix.com/downloads/MDBConverter/MDBConverter.zip
unzip MDBConverter.zip
How to run the Master Demo:
cd MDBConverter
mono MDBMasterSimulatorConsole.exe /dev/serial0 115200
-> For master operation, please make sure to set the DIP Switch to ON-OFF-OFF-ON-ON
How to run the Cashless Device Demo:
cd MDBConverter
mono MDBCashlessDeviceSimulatorConsole.exe /dev/serial0 115200
-> For slave operation, please make sure to set the DIP Switch to OFF-ON-ON-OFF-OFF
Hint: On newer raspbian releases, the serial port is available as /dev/serial0 - older releases may use dev/ttyAMA0.