# Power and Hardware 2021-2022 Debrief

## Observations/Problems

### Design Phase
- Change in design specs
- **Did not have specific component list by CDR**
- P&H descision making and planning is dependent on finalizations from other subteams
- List by CDR
- Drivetrain
- Encoders (4 total): velocity control
- Excavation
- Current Feedback on exc motor: prevent motor stalling
- Actuation
- Limit Switches (6 total):
- 2 for stopping left linear actuator (full extension and halfway)
- 2 for stopping right linear actuator (full extension and halfway)
- 2 for lead screw actuation (full extension and zero extension)
- Deposition
- Limit Switches (2 total): 2 for stopping deposition movement
- Weight Sensor:
- For determining when enough gravel has been mined
- Additional changes
- Reduced 8 limit switches to 3 hall sensors
- LED signal
- Didn't need 5V step down if we used motor controllers that provided a 5V output voltage, saving space
- Sabertooth motor controllers have 5V output
- Custom motor controllers vs Sabertooths
- Cost
- Size
- Component Placement
- Need component list to define the size of the box
- Hard to incrementally do component placement
- Constant components
- Motor controllers
- Encoders
- Jetson + teensy
- power distribution

### Manufacturing
- Not clear which pin on the bulkhead is routed to which pin on the teensy
- Routing done prior to assembly would simplify this greatly
- Not clear which spreadsheet has what information
- A table of contents as minimum would be greatly helpful to find information
- Very easy to mess up the orientation of the bulkheads while soldering it (Happened twice)
- Had to ask to get the PCB layout multiple times, easiest and best piece of documentation for assembly
- Had the Teensy USB port get ripped off multiple times
- Use USB pins with ttyl cable instead of micro usb?
- doesn't work, better option is to route the cable more safely so when it bends it doesn't apply a lot of torque on the usb port
- Got the ebox too late (April-May instead of February)
- Lot of waiting

### Mitigations

- Clearer Documentation
- Datasheet (Software/P&H)
- Includes full schematic with pinouts
- Full component list with links to respective datasheets (for easy ctrl-F)
- Define clear notation of robot and actuators (i.e front-left drive motor, excavation motor, left linear actuator, right linear actuator, assume front is in direction of tool, forward is +x direction, etc)
- Full component placement diagram with wiring done in Solidworks and wire lengths ([link](https://www.cati.com/blog/how-to-create-a-solidworks-electrical-route/))
- Battery handling (could be added in wiki)
- Due with robot CAD in January?
- Space for changes in design
- If changes are made, need to go through official approval
- Proactive Communication
- P&H should make a specific list of what the minimum information is needed to proceed with planning (type of sensors, box size etc.)
- Design
- Put battery outside box
- Plastic box with sealed enclosure like a lunchbox
- Potentially outsource box design to Protocase
- Search "plastic waterproof electrical enclosures" on google
- Need specified dimensions first
- Create a P&H box and design the mechanical system around that
- Wire routing in design phase, either through Solidworks or by hand
- ** need to have component list first