MDB vending development KIT

This kit was developed for internal use for faster vending development. Using this kit, our company can quickly develop any vending machine prototype. It contains few boards that can be interconnected by MDB bus and can also manage MDB payment systems through an MDB slave to master interface converter. Beside the devices described below, this kit can include RASPIVEND (click here for details) or RASPISLAVE (click here for details) to interface a touch-screen and create a touch-screen based vending machine. There is, also, possible interfacing with MDB to Executive bridge RASPI (click here for details)

Using this KIT we can develop any vending machine you might think about, with alphanumeric and mechanical keyboards or touch-screen interfaces.

1. Alphanumeric LCD display with MDB slave interface, uC, matrix keyboard interface and RTC.

This device can be the core of the new developed vending machine or can be simlpy used as a slave for keyboard/buttons input and text output:


  • Real time Clock and 8bit Microchip microcontroler (PIC18F26K22);
  • MDB slave interface;
  • matrix keyboard or mechanical buttons interface with 4 columns and 6 rows multiplexer;
  • power supply for logical circuits and LCD, directly from MDB bus.


2. I/O board

This board is used to control high power peripherals and has, also, other interfaces for temperature sensors, door contact or level sensor, etc. the board is an addresable model, with 3bit address. On a single bus there can be connected up to 8 boards with different addresses, extending I/O cappacity.


  • MDB slave inteface, powered from MDB bus;
  • 2 isolated inputs
  • 1 x positive or negative (open collector) flow-meter input;
  • 4 x 1wire sensors;
  • 8 x 8A/250VAC relays;
  • Real time Clock and 8bit Microchip microcontroler (PIC18F26K22);

3. Spiral motors driver board (8 drawers with 16 motors each - up to 128 motors)

This board is used to control 24VDC spiral (snak) motors with 2 wires and includes a current sensing curcuit for turn counting.


  • Current sensor for turn counting;
  • Real time Clock and 8bit Microchip microcontroler (PIC18F26K22);
  • MDB slave intrerface.




4. MDB slave GPRS module with RS232 interface

This board is used to communicate to a remote server over the GSM network (GPRS). It can be also used as a remote MDB cashless device.


  • Real time Clock and 8bit Microchip microcontroler (PIC18F26K22);
  • MDB slave inteface;
  • RS232 inteface;
  • Microcontroller on board
  • GPRS module with SIM card holder.




5. MDB slave to MDB master interface converter

This module can convert any of the above into a master module that can manage payment systems and, also, any other slave modules to develop basic and extended functions of the vending machine prototype.