Arduino Vending Integration Support
Budget: $10 – $30 USD
I’ve put together a prototype smart vending machine around an Arduino UNO that authenticates users with an RC522 RFID reader, lets them pick Snickers or Skittles on a 4 × 4 keypad, and drives stepper motors to release the selected treat. Each part works on its own, yet when I run the full sketch the system freezes, tags go unread, or the wrong motor spins.
I don’t have a complete wiring diagram yet, so one of the first tasks will be helping me draft a clear schematic before we dive into the code. From there, I need comprehensive guidance:
• Debugging the existing sketch so RFID login, keypad input, and AccelStepper control cooperate without blocking the loop
• Advising on clean wiring, power distribution, and noise suppression to keep the motors from browning-out the UNO
• Recommending performance optimisations—state machines, debouncing, timer interrupts—so the dispenser stays responsive
Deliverables
1. A revised, well-commented Arduino sketch ready to upload
2. A simple, shareable wiring diagram (Fritzing, Eagle, or clear SVG)
3. A brief change log explaining what you altered and why, so I can learn for future iterations
Acceptance criteria
• Valid RFID tags always grant access; unknown tags are rejected
• Keypad registers every keypress without ghosting
• Correct stepper turns the right number of steps and then stops
• Main loop remains responsive during any motor activity
My starting budget is $5, but I’m happy to negotiate upward for experienced, teach-as-you-go assistance that gets the machine dispensing reliably. If you’ve tamed RC522 readers, membrane keypads, and steppers before, I’d love to work with you.
I don’t have a complete wiring diagram yet, so one of the first tasks will be helping me draft a clear schematic before we dive into the code. From there, I need comprehensive guidance:
• Debugging the existing sketch so RFID login, keypad input, and AccelStepper control cooperate without blocking the loop
• Advising on clean wiring, power distribution, and noise suppression to keep the motors from browning-out the UNO
• Recommending performance optimisations—state machines, debouncing, timer interrupts—so the dispenser stays responsive
Deliverables
1. A revised, well-commented Arduino sketch ready to upload
2. A simple, shareable wiring diagram (Fritzing, Eagle, or clear SVG)
3. A brief change log explaining what you altered and why, so I can learn for future iterations
Acceptance criteria
• Valid RFID tags always grant access; unknown tags are rejected
• Keypad registers every keypress without ghosting
• Correct stepper turns the right number of steps and then stops
• Main loop remains responsive during any motor activity
My starting budget is $5, but I’m happy to negotiate upward for experienced, teach-as-you-go assistance that gets the machine dispensing reliably. If you’ve tamed RC522 readers, membrane keypads, and steppers before, I’d love to work with you.