Implementation of the eSSP controller program for managing the NV200 banknote acceptor + SMART Payout is required.

Banknote acceptor with cash box

NV200 + SMART Payout

from the company Innovative Technology

Development of a controller for working with the banknote acceptor using the eSSP protocol

Project goal

To develop C++ code for a controller that will test various operating modes, check and manage the device using the eSSP protocol via RS232.

Current situation

• The device is controlled by simple unencrypted commands (usually 6 bytes) and encrypted commands using the Diffie-Hellman algorithm.
• I have a USB → RS232 adapter, with which I have already tested basic unencrypted commands on Linux , such as:
  • Sync, Poll, SetProtocol, SetInhibits, Enable, EnablePayout.
• I do not have a complete understanding of the algorithm for working with encrypted commands.
• I have official documentation and source codes for Windows/Linux, but they are partially closed as they use compiled binary files in the SDK library.
• The manufacturer Innovative Technology does not provide support beyond its SDK and refused to provide firmware with encryption disabled.

Development requirements

• Full implementation of the encrypted eSSP protocol, including the Diffie-Hellman algorithm.
• Development of code from scratch, without dependence on the manufacturer's SDK, so that it can work on a controller without an operating system.
• Support for all necessary commands and interaction algorithms with the device.
• Ideally — porting the code to ESP8266 / ESP32, to create a separate processor that:
  • Receives simple commands from other devices or controllers.
  • Executes all complex interaction algorithms with the acceptor.
  • Returns statuses and results of operations.

How the system should work

The finished controller should perform all the complex logic of working with eSSP and accept simple commands such as:

• "Accept banknotes"
• "Dispense amount"
• "Move banknotes to cash box"
• "Get error status"
• "Optimize banknote dispensing"

The controller itself should handle all commands, statuses, and algorithms, while the external controller (for example, a microcomputer, terminal) only needs to send a high-level command without knowledge of the specifics of working with eSSP.

Who am I looking for?

I need a specialist who:

• Has already worked with the eSSP protocol and understands it at a low level.
• Is knowledgeable in encrypted data exchange and the Diffie-Hellman algorithm.
• Has experience in development for microcontrollers (ESP8266 / ESP32 is a plus).

If you do not have experience working with eSSP and encrypted commands, it is unlikely you will be able to help with this project. However, if you already have developments or knowledge in this area, I am ready to provide all the information I have received from the manufacturer.

Additional details

The project will be iterative – most likely, new modes and functions will need to be added during the work as requested by the client. At this stage, the main goal is to implement encrypted eSSP and basic operations.

If you have the necessary knowledge and are ready to work – let's discuss the details.