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Fab Academy AS220 - Providence, RI Fab Academy Providence -Year II - Teaching

FabRC – Project Developments

I am working towards my Fab Academy final project – a digitally fabricated RC car.

Items Completed So Far:

Radio boards have been designed (based on the JeeLabs RFM12B Board)


I designed the battery connector boards
battery_schem
battery_board

Hello Arduino boards milled, stuffed and programmed with Arduino bootloaders and tested with the servos

Tasks That Still Need to Be Completed:

  • Radio boards need to be milled and assembled.
  • Battery connector boards need to be milled and assembled.
  • Radio boards need to be tested to see if they communicate with each other
  • Car controls need to be figured out
  • Code needs to be modified / written and tested to make the radios communicate with each other.
  • Code needs to be written for the car controls.
  • Car framework (wheels, axels, body) needs to be designed and assembled

Items That Still Need to Be Resolved / Not Working Yet:

  • No analog pins on the Hello Arduino? How to hook up the controls?
  • Use Fabkit instead? (burned the bootloader, but the Arduino IDE won’t talk to the chip).
  • “Fingers crossed” that the radio boards will actually work.

Completion Schedule:

  • Planning on completing the project by the June 1 deadline . Otherwise, before the August 15 final completion date.
Categories
Fab Academy AS220 - Providence, RI Fab Academy Providence -Year II - Teaching

FabRC – Final Project Planning

This week at Fab Academy we are planning our final projects.  I am creating a digitally fabricated RC car.  First I defined my all the system components, how they would interact with each other and what the logic / voltage levels needed to be throughout that system.

Logic Levels / Radio – Functional Block Diagram

What Will It Do?

  • Drive forward / stop
  • Turn left / right
  • Use radios to control the car wirelessly.

Who’s Done What Beforehand?

  • David Mellis made pressfit cars – this one needs to be more of an enclosure to house the electronics
  • JeeLabs: http://jeelabs.org/ has created some code and designs that I plan to modify and use with the Hope RF radios.

What Materials and Components Will Be Required?

  • 2 servos
  • 2 radio boards (utilizing the Hope RF radios)
  • 1 or 2 Arduino boards (hello Arduino boards)
  • Masionite
  • LEDs (possible decoritive addition)
  • Acrylic (possible decoritive addition)
  • Possibly plastic to cast parts (possible decoritive addition)
  • Metal rods for axels?
  • copper-clad PCB stock
  • Various components already in the inventory

How Much Will It Cost?

  • $0 – $20 Most parts already in the inventory.
  • Need to purchase Hope RF radios – $12.00 for a pair.
  • Need to purchase a few additional non-standard, non-inventory components from Digikey ($10.00 + shipping).

What Parts and Systems Will Be Made?

  • Connect the radio boards to the Arduino
  • Figure out how to issue commands to control the car
  • Turn lights on and off

What Processes Will Be Used?

  • Laser-cut press fit for the car body (possibly being replaced by molded shell / parts)
  • Milled circuit boards.
  • Molded parts for wheels / accessories

What Tasks Need to Be Completed?

  • Need to investigate how to get the boards to talk to each other.
  • Control with computer keys at first.
  • Would like to eventually add a wireless joystitck control box.

What Is The Schedule?

  • This Week –> Design the car and investigate the how to talk to the radios
  • Next Week –> Troubleshoot the project, work on the control structure.

How Will It Be Evaluated?

  • Can the radios talk to each other?
  • Do the controls work?
Categories
Fab Academy AS220 - Providence, RI Fab Academy Providence -Year II - Teaching

Working MTM Snap – Almost Complete!

MTM Snap – Z and X and Y Axis Working

Jonathan Ward came down from MIT to Fab Academy AS220 @ AS220 Labs to help us with our MTM snap machine. We were missing some critical parts, so he helped us get what we had in stock to work with his design. At this point the machine is working – but we need to replace the individual stepper boards with the shield (we need the increased capacitance and we think we may have cooked the boards a bit with some initial faulty wiring.) We are also waiting for some thrust bearings to come in from McMaster Carr. They should be in shortly and I will publish an update.

Categories
Fab Academy AS220 - Providence, RI Fab Academy Providence -Year II - Teaching

Hello Serial Bus

bus

The purpose of this hello world example is to network several boards together in the form of a serial bus. The bridge board is connected to a computer via a FTDI cable. The two node boards are connected to the bridge board.

To replicate this example:

  1. Download the Fab Academy board diagrams / pngs and code.
  2. For each node in your network, you will need to modify the modify the “hello.bus.45.c” code.
  3. You need to change the line: #define node_id ‘0’ –> each node needs to have a different number (0, 1, 2, 3 – for each additional node you add.
  4. After flashing boards with 3 different node numbers:
  5. Open a Arduino IDE
  6. Open the serial monitor
  7. Enter number of note into serial monitor – press “enter”
  8. The node name (ex: node 1) should echo in on the serial monitor and the LED on the board that was flashed with the node id of 1 should flash.

Alternately- If you don’t have / want to use the Arduino IDE,

  1. After flashing boards with 3 different node numbers:
  2. Download term.py.
  3. Run term.py

In Ubuntu this is:

python term.py /dev/ttyusb0 9600

The node name (ex: node 1) should echo in on the serial monitor and the LED on the board that was flashed with the node id of 1 should flash.

Bus In Action