Vending Machine System with Raspberry PI

Job ID: 40427712

Budget: $750 – $1,500 USD

Seeking a Software Developer & Electronics Engineer building innovative IoT and embedded systems.
Must have experience and sample project regarding Vending machine connected with Raspberry pi through MDB-to-RS232.
Please include sample project screenshots or url. Answer one question about attached screenshot.
"What do numbers in request mean? What is MDB Interface command to vend approval from Raspberry Pi?
If you don't include above reference and answers, your bid will be ignored.
Best