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dig:dig11:board_assembly

Copper Board Assembly Guide and Videos

Video Player help: In case you can't play the video go get the open-source VLC player from: http://www.videolan.org/

Step 1: Getting Started with the 5V rail and the PWR LED

Before starting with this step, watch this video.

In this video you the assembly and testing of some components which are simple to solder is shown. These components are: - L1 - Ferrite Bead filtering noise out of the 5V coming from the USB host. - R4 - 220 Ohm resistor limiting the current for the PWR LED - C5 - 100nF cap buffering the 5V rail - PWR - green LED showing that the board is receiving power over USB - X2 - female mini-USB type B connector

After all these components are soldered, the green LED should go on once you connect your board to a computer…

Check 1

Measure the voltage across C5. It must be within 5V +/- 5%.

Step 2: Soldering the 3.3V rail stuff

Solder: - U2 - Linear Regulator 3.3V - C1 - 4.7uF cap buffering the 3.3V rail - C2 - 100nF cap buffering the 3.3V rail

Check 2

Measure the 3.3V rail voltage over C1 or C2. The voltage must be within 3.3V +/- 5%.

Step 3: solder the difficult parts

Before soldering the next components, watch this video: [https://neuromorphs.net/2010-smd-usb/video/sc05-avr32-crystal.avi sc05-avr32-crystal.avi]

In case you create bridges between the microcontroller pins:

  • make sure that they don't have to be there: Check with a blank PCB whether the two pins are connected by a trace directly in between.
  • Remove extra solder to clear the bridge:
  • Use another other soldering iron with a big tip
  • Set this iron to maximum temperature
  • Use the 0.6mmsolder wick
  • Cut off the used parts of the wick and use the fresh end of the wickto minimize the energy being pulled away by the wick
  • Turn off that iron after you are finished removing solder…

Now it is time to solder: - U1 - our USB microcontroller AT32UC3B1256 - Q1 - The 12MHz crystal

If you are confident that U1 and Q1 have been soldered correctly, you can solder the remaining (easy) components: - C8 - 100nF cap buffering the 3.3V rail - C3 - 100nF cap buffering the 1.8V rail - C4 - 2.2uF cap buffering the 1.8V rail - C7 & C6 - the 16pF crystal load capacitors - R3 - 47kOhm TCK pullup resistor - R1 & R2 - 39Ohm USB data lines series resistors - RST & DFU - the two micro switches

Check 3

After plugging in the board to a computer, check all rail voltages again:

'Measurement Site' 'Nominal Value'
C5 5.0V +/- 5%
C1 3.3V +/- 5%
C4 1.8V +/- 5%

If any of the voltages are out of range 'disconnect the board immediately' and start visual inspection, and have someone else look at the board.

Check 4

Let's check the oscillator: * Attach a wire to some GND pin. * Connect the scope ground clamp to the wire * Check the signal on C7, on the non GND side (not the C-side, the 7-side…) * You should see a (more or less sinusoidal) 12MHz signal with about 1Vpp amplitude…

Check 5a

Connect your board to a Linux computer, then run the command 'lsusb' in a shell.

Besides other devices you should see: bus_device}

Check 5b

To get further information on what Linux found out about the device, run 'sudo lsusb -d 03eb:2ff6 -v'

You should get this: bus_device}

' You made it till down here? Congratulations! ' Your board passed all tests that do not require a 'test-firmware' to be flashed…

Continue on the: '[wiki:2010/usb10/AtmelAVR32 Atmel ACR32 USB firmware page]'…

dig/dig11/board_assembly.txt · Last modified: 2024/02/29 07:28 by 127.0.0.1