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Avionics crash course

Pcb design in altium c++ firmware devekioment digital citrcuits analog circuits owernerships flexible projects make friends exact skills that will get you a internship/job

remember, you will get what you put into it

You can coast in any subteam and put it in your resume, but you wont get anything out of it

Workflow

PCB designed in ALtium ordered from jlcpcb parts from digikey with assembly for complex boards boards are hand solders, sometimes with stencil simple test and connectivity test ep32 is flashed with cpp firmware bringup continues until board is working often reworked, respun in bad cases mechanical enclosure in onshape/software tolles created (ie GUI)

Intro project

you can choose any project -> anyone who choses the same projects works on it together i na group. Every project has a mentor assigned to be your primary poc work colosely with your ementor and your group!

Accelerated timeline (should be comepleted in one month) 7-10 hours per week depedns on your skill level and project async learning: be willing to fill gaps in your knoweldge on your onw

Ge thelp, I will have drop in office hours and communicate with your mentor.

Diablo Avionics

What is diablo

3rd liquid engine, second liquid vehicle regneratively cooled Pressure Fed Tank Regulation Scheme to regulate the pressure of the tank LE3

What are the avionics projects

Data Aquisionts (DAQ) Collect Hotfire data from many sensors Actuates valves to regulate pressure, abort fires, etc. Uses a server to process and display data on webs serve Much more detal later on tday Flight avionics: In R&D, will pick up speed after DAQ finished, Flight computer: captures data during flight, including acceleration, air pressure, and rotation and uses it to determin vehicle states

What is a DAQ

For testing the engine during a Hot-fire Aborts automatically, manual aborts Solenoid Valves

Sensors

Load Cells for measure thrust Pressure transucers, measure pressure to regulate pressures Thermocouples to measure combustion chamber temps RTD temperature sensors for lower temperatures (Tanks, lines, etc.)

Design Goals

Modular: Easy to add new seneors

Abstraction: each board is a complete system, does not have to rely on other boards much. Includes power regulation(AKA Power Block) Includes microcontroller

Communicated through Ethernet, One switch controls everything everything important happens on the server, the boards just follow commands.

Each of the boards

Power Distribution

Provides power to all the daq boards, low volatage (takes 12v, regulates to 5.5v) For low voltage, takes in 12 v from psu lv needed for all boards for high voltage takes 12-24 from psu - board connectors

Actuator Board

Actuates and senses current going into each valve Used to determine. if fuses or wires have tripped/broken

RTD Board

Responsible for accurately sensing 4, 3 wire rtd Resistivity changes with temperature, 100ohm at 0C

TC Board

Thermocouple 10 TC maximum Seebeck effect (2 wires of different metals, and they meet at a hot junction and theres a small voltage across the metals when hot) Junction Compensation, if we read temp at cold junction, then no need for error, if we read at the dac, then we need to accont for error.

LC Board

Load Cells: Force sensors, when they comrpess they reduce resistance and vice versa Ratiometric, so output V is ratio to input V

PT Board

Responsible for Pressure Transducers, etc. Generally outputs a signal etc. So there are 2 signal wires. xt60 connector for different PTs, etc.

Prop Board

Reads Motor encoder RS45 Encoder Board (Comm protocol) Motor has a weird connector with weird scheme, so we just stick it on the prop board. Capacitive Fill, and motor encoders RS45 is 2 lines, one high and one low, so it communicates over long distances, designed for very noisy environments. Motor Driver, just weird, gave it to the prop board.

Intro Projects

Power Distribution PCB

First iteration of the power distribution pcb has been designed but it cant measure the curerents or volages on each channel. Goal, make a new power distributuion board that sens the input output volages and current process them thwith microcontroller

PT Excitation Power Supply PCB

Provide 24 volts very clean (no noise) Power FIlters Power Protection Circuits No Coding

Capactitive Fill Sensor PCB

Constant for Air VS Liquids changes, so the PCB needs to measure capacitance.

DAQ Server Briefcase

NVIDA RPI, ROUTER, ETC Making it accessible, etc. Needs Mechanical Enclosure

RF System + Testing

The boards will not be used on the rocket, will not be easy at all. VNA equipment testing over 30k ft. def the most complex.

Live Video GUI

Telemetry, Video, etc, Cool Visualization Goal will be to create the gui to make it pretty. Converting Digital Signals into pretty interface

DAQ Integration and Testing

Just wanna start working on the DAQ

Briefcase

  • Harbor Freight Briefcase
  • Aim for under 200
  • Talk to a company for a free monitor
  • plastic sorta case
  • Urban ore, in berkeley, could have some nice cases
  • could be ca good plce to look
  • measre, peripherals
  • monitor is on the top half of case
  • could do somethig like a trackpad keyboard, etc. up to me.
  • some keyboards made for servers.
  • some sorta jetson nvida rpi thing, kush is getting one for free
  • Server needs to connect to some ethernet switch, dont need to do anything to it. 5port switch is prob fine.
  • things that plug in
    • server
    • dac box
    • laptop, need a couple extra ports
  • needs a router, that is small and can fit ion the case.
  • Needs to look cool
  • soemthing cool was a tablet that was connect to the server, and could keep track of the valves etc.
  • No need but would be nice dust proof waterproof
  • other thing that could be troublesome, need to connect the ports to