Assembly Guide and Videos for copper board

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

Before starting with this step, watch this video: sc01-getting-started.avi

In this video you the assembly and testing of some components which are simple to solder is shown. These components are:

  1. L1 - Ferrite Bead filtering noise out of the 5V coming from the USB host.
  2. R4 - 220 Ohm resistor limiting the current for the PWR LED
  3. C5 - 100nF cap buffering the 5V rail
  4. PWR - green LED showing that the board is receiving power over USB
  5. X2 - female mini-USB type B connector

After all these componentes 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


  1. U2 - Linear Regulator 3.3V
  2. C1 - 4.7uF cap buffering the 3.3V rail
  3. 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: 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 the other soldering iron with the big tip
    • Set this iron to maximum temperature
    • Use the 0.6mm solder wick
    • Cut off the used parts of the wick and use the fresh end of the wick to 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:

  1. U1 - our USB microcontroller AT32UC3B1256
  2. Q1 - The 12MHz crystal

If you are confident that U1 and Q1 have been soldered correctly, you can solder the remaining (easy) components:

  1. C8 - 100nF cap buffering the 3.3V rail
  2. C3 - 100nF cap buffering the 1.8V rail
  3. C4 - 2.2uF cap buffering the 1.8V rail
  4. C7 & C6 - the 16pF crystal load capacitors
  5. R3 - 47kOhm TCK pullup resistor
  6. R1 & R2 - 39Ohm USB data lines series resistors
  7. 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 ???: ID 03eb:2ff6 Atmel Corp.

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 ???: ID 03eb:2ff6 Atmel Corp.                                                                                                         
Device Descriptor:                                                                                                                                   
  bLength                18                                                                                                                          
  bDescriptorType         1                                                                                                                          
  bcdUSB               2.00                                                                                                                          
  bDeviceClass            0 (Defined at Interface level)                                                                                             
  bDeviceSubClass         0                                                                                                                          
  bDeviceProtocol         0                                                                                                                          
  bMaxPacketSize0        64                                                                                                                          
  idVendor           0x03eb Atmel Corp.                                                                                                              
  idProduct          0x2ff6                                                                                                                          
  bcdDevice           10.00                                                                                                                          
  iManufacturer           1 ATMEL                                                                                                                    
  iProduct                2 AT32UC3B DFU                                                                                                             
  iSerial                 3 1.0.2                                                                                                                    
  bNumConfigurations      1                                                                                                                          
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength           27
    bNumInterfaces          1
    bConfigurationValue     1
    iConfiguration          0 
    bmAttributes         0xc0
      Self Powered
    MaxPower              100mA
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           0
      bInterfaceClass       254 Application Specific Interface
      bInterfaceSubClass      1 Device Firmware Update
      bInterfaceProtocol      2 
      iInterface              0 
      Device Firmware Upgrade Interface Descriptor:
        bLength                             9
        bDescriptorType                    33
        bmAttributes                       15
          Will Detach
          Manifestation Tolerant
          Upload Supported
          Download Supported
        wDetachTimeout                      0 milliseconds
        wTransferSize                   65535 bytes
        bcdDFUVersion                   1.01
Device Status:     0x0001
  Self Powered

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: Atmel ACR32 USB firmware page...