PIIO Construction

To construct a PIIO board you first need the PIIO PCB board.
All the components you need is in this component list.
And of course a soldering iron and solder. Some steps are quite fiddly so you can not have too big tip on the solder iron.

Follow this page and component list from the top to bottom, do not jump ahead, some things need to be done in the right order.
In order to know which component is which see the column Picture.
See the column Name on PCBQtyLocation and Symbol on PCB to find the location on the PCB.
Also read the Description and Soldering column if there is something that you must consider...

Below are images with brief descriptions how to go about the construction.


Most of the components is on the TOP but some is also on the bottom.
So you need to search fort the components location on both the top and the bottom.

  The PCB top                                                                The PCB bottom


First solder all resistors, on some places the holes is close together, try not to let the solder float to the other holes or it will be more difficult to solder the rest later.
  PCB Top                                                                       PCB Bottom


Do not attach it is the wrong way (C, B, E)
  PCB Top


Check + and - on the Tantal and Electrolyt. 
Must connect the long leg to +
  PCB Top                                                                       PCB Bottom

Trimpot, Diode and Fuses

Cut of the right leg on the trimpot. You only need the middle and left one.
(In the picture it is the left leg, 
because it is upside down)
It is quite difficult to access soldering the trimmer...
For the diodes you must connect the side with the ring to - 
Here i use two 2A PTC fuse for the SN754410NE motor driver. It is only rated for 1A but i will solder two SN754410NE on top each other with a heatsink later.
And also o 5A PTC fuse for the whole board, you can leave that and bypass with solder...
  PCB Top                                                                       PCB Bottom

LED and Summer

The long leg on the LED to + and the flat side is -.
On the summer 
connect long leg to + (also marked with a +)

Button and switch


Note the indented side (must solder the right way).
And on the PO12_I2C you must have the third leg from the bottom on the left side removed.
Then it's just to solder like a madman... 

Buck Converters, Main power in and some male PINs

  1. First solder the male pins (V_MAIN, V_ADJ_ON, 5V_REG) on the top.
  2. Then the 8 pins for the buck converter on the bottom of the PCB.
  3. Then solder the 2 large screw terminal to the top.
  4. No you must set one of the Buck converters to 5V before solder it
  5. Then solder the 5V buck converter ti the right and the other to the left.
    Do not push them to the bottom, leave a bit between the twp PCB board.
    See the picture below.

Level shifter

  1. First solder the pins for the level converter on the bottom of the PIIO board.
    Observe that if you use a TXB0108 or a LS1 one of the pin rows is on different place.
  2. Then the GPIO_5V and GPIO_5V_ON pins on the top of the PIIO board.
  3. Then solder the lever converter (i use the TXB0108)

Pin headers

  1. Solder GPIO pin 1 to 12 above the CONNECT_PI
  2. The 2x20 Pin  Extra hight header need some fixing.
    Take some male pins and remove the pins. Then cut them in pairs, you need 4 pairs.
    Then add to the 2x20 Pin like in the picture.
  3. Then solder it to the bottom of the PCB.
    You need to solder one row first then cut of the pins to reach the next row.
  4. Now solder all the remaining male pins...they are all on the top of the board.
    When i solder i put a tape to hold down the pins.
    In this picture I have missed soldering the pins between the screw terminals in the top right.
  5. Solder the 4 pin female on the top for the LCD.
  6. Then the 3 pin female pin on the bottom for the external 3.3V
  7. And finally the two female headers for the gyro.
    And also solder male pin to the gyro board.

Screw terminals

Solder the screw terminals like this.


  1. Cut of the bottom right pin on the relay.
    In this picture it is on top right because it is upside down.
    Put some plastic tape on the cut of pin so that it can not short out against the PCB.
  2. The solder the relay to the PCB.

Optional: DAC

If you want the DAC solder it like in the picture.

Optional: OLED Display


Optional: Extra motor driver with heatsink (About 2A)

If you solder a extra SN754410NE on top of the other and add heatsink it can handle more current.
I think at list 2A should work.
  1. Add some heat sink to the top of the already soldered IC.
  2. Then clamp them together and solder on top of the other.
  3. Add some heat sink to the top of the new IC and press the heat sink.


  • Internal 5V regulator
    If you want to use the internal 5V regulator add a jumper to 5V_REG pins
    If you have 5V as input you can disable the internal regulator by adding the jumper to BYPASS_5V_REG instead.
  • 3.3V regulator
    If you want to use the 3.3V regulator in the Raspberry Pi put jumpers on the two PI_3V3_REG.
    If you use a external 3.3V connected to EXTERNAL_3V3_REG, do nut put any jumper to 
  • Adjustable voltage
    If you want to use the V_ADJ (adjustable voltage) add a jumper to V_ADJ_ON
  • 5V GPIO
    Enable the GPIO_5V by adding jumper to GPIO_5V_ON.
  • Motor driver
    To use the DC motor controller MOTOR_1 and 
    MOTOR_2 add jumper to V_M (between the blue screw terminals).
  • Servo controller
    If you have 5V servos put a jumper to V_SERVO.
    Otherwise, you run a cable with the correct voltage to SRV.

Link with Raspberry PI

  1. Screw the pillard to the PIIO board
    And add a tape to the USB and LAN contact in the Raspberry Pi (So there can be no short).
    It's also a good idea to cut away as much as possible of the small protruding pins on the bottom.
  2. Now plug and screw the Raspberry Pi to the  PIIO board.

Now everything is finished

Just connect a SD card with Steelsquid Kiss OS och start building stuff :-)