Arduino shield PCB Design

Scope of work
- Design two stackable Arduino UNO R4 shields
- Board 1: isolated IO and power control using relays
- Board 2: serial communications with RS232 output
- Maintain full USB serial access for debugging
- Provide schematics and PCB layout files

References
- Wiring diagram and stack details will be provided
- System includes Arduino UNO R4, custom shields, and Zaber XAS01 shield (https://www.zaber.com/products/accessories/X-AS01)
- External device: IVEK dispenser via serial commands

Additional information
- Standard Arduino shield footprint
- Relay isolation required (5V and 24V relays)
- RS232 output via screw terminal connector
- USB serial must remain free at all times
- Stackable boards with pass-through mounting holes
- Clean silkscreen with labels and branding
- Full file handover required, IP assigned to us