Credit Card and QR Payment Terminal

I am looking for a competent professional to develop a simple process of send a fixed payment amount to an unattended payment terminal to trigger an equipment with MDB signal.

Key Responsibilities:
- Able to display a fixed amount to send to the Android unattended payment terminal
- After payment is completed, payment terminal to send signal via MDB port to trigger the machine operation (the machine is ready to receive signal via MDB)

Ideal Candidate Capabilities:
- Background and knowledge in payment terminal integration
- Familiarity with minimalist design principles
- Proven experience in unattended payment terminal software integration with API / SDK and MDB protocol