4.7 KiB
Dependencies
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Form factor from mechanical engineering
- --> where to place antenna connectors?
- --> where to place pdb?
- --> where to place batteries? What form factor for batteries?
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Protocol decision to know what pinout we need.
Schematics
Estimate: 16 days
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- Add main components
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- SOM connector
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- LTE-Chip
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- All connectors (generic with #pins correct)
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- Additional pins that could be useful, all in one connector. 1
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- All power Ics, which ones? What are requirements? 2
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- Add supportive passive components for Ics according to their datasheets 4
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- Think about redundancy and fuses. Protect from different faults. 2
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- Have a working camera solution. What cameras are compatible with MIPI and Qualcomm?What connector do we want for them? 4 --> inigo needs to find a solution
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- Schematics review. Double check with all datasheets that things are in order. 3
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- Go through every net and define purpose. Is it only connected to that net?
PCB Design
Estimate: 15 days
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- Define form factor with Romain. Think about manufacturability from beginning. 4
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- download 3d model of SOM and connector.
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- Define plate with +- 7mm or so for pcb and components.
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- Use as structural element?
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- Where will PDB be?
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- How are the 2 boards connected?
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- Should we have a third board? --> sensor board, additional imus and gps
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- Where the batteries?
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- Define min track width, stackup, etc.
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- Define main areas (power switching far away from analog signals) and place main components. 1
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- What can be underneath the SOM?
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- Place components and use as small components as possible. 3
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- Use both sides of the board to make it small.
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- Redo schematics review. 1
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- Route high speed signals and antenna tracks 3
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- Route other data tracks 2
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- Add planes. 1
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- Add stitching vias everywhere.
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- Review design.
Requirements
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UART to PX4 (with jst connector)
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Connector for GPS-module / pixhawk standard?Or Integrated GPS module? Or both
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Connector for UAVCAN
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For RB5s
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To Esc (with a solder bridge). If dshot escs can is routed onboard, else via escs
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Which one is terminating node?
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LTE-link (one 4g, one LTE-M)
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2 Cameras per computer (or 4 through mipi splitter?)
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Power delivery network
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Connection between Qualcomms (ethernet vs usb-c)
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Wifi and bluetooth.
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Can the antenna connector on the SOM be used?
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Document every decision and step
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GPIO to reset other qualcomm
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GPIO to reset FC
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Main switch to
Preparation
Estimate: 7 days
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- Understand Qualcomm platform 2 days
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- How is power routed exactly?
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- How are camera signals routed?
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- Decide which ports are going to be used for what peripherals 0.5
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- Choose LTE-chip 0.5
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- --> 4G chip (redundant)
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- How can we control drone through 4G?
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- Choose GPS solution / chip or external 1
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- Are there any high precision modules available on the market?
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- Can we easily implement them into our design and manufacturing?
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- Decide on solution for inter-RB5 communication 1
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- PCIe ethernet & usb-c receptacle? We can test both simultaneously.
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- Test with corals: usb-c to usb-a: always feasible?
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- Implement both? --> not for redundancy reasons.
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- --> usb-c!
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- Define all pins that could be needed and provide them through a connector 1
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- All uart ports, all i2c, all SPI. Nets to observe for debugging.Power rails to observe, additional gpios
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- Decide what power rails are needed, how many voltages, redundancy? 1
Questions to answer
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Have we tested everything we could in the prototype stage? With breadboards and jumper cables, etc?
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What sensors do we want?
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A few temperature sensors on I2C bus
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Additional IMU's? away from ESCs
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Redundancy: split into 2 boards? Electrical isolation?
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Does the SOM have wifi antenna and bluetooth antenna?if not, what antenna do we use? Pcb antenna integrated into our design? Or pluggable antenna?
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Do we want flash storage? To collect datasets. Or is onboard storage enough
Review, Order & Shipping
Estimate: 2 + 15
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- Redo reviews (schematics and pcb) with other person.
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- Order
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- Shipping
Testing & Debugging
Estimate: 7 days (can be a lot longer if board doesn't work)
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- Define tests
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- Execute Tests & document results