Assembling
In this document, we will be going through the main practical steps to put together a Linaro Automation Appliance (LAA). As an example, we will consider as Device Under Test (DUT) a Raspberry Pi 4 Model B.
It’s recommended to use an anti-static mat and wear the anti static wrist strap. Make sure to connect the mat and the strap to the ground.
Here is a list of what we need:
Standard Interface Board (SIB)
Mechanical Interface Board (MIB)
Jumper for the 3v3 pin
Raspberry:
Raspberry PI Model 4 B
32 GB SD Card
(optionally) x4 M3 plastic screws
(optionally) x4 17 mm M3 brass spacers
(optionally) x4 M3 hex nuts
Temperature Sensor
Supports:
x10 30 mm M3 brass spacers
x10 M3 plastic screws
x8 17 mm M3 brass spacers
x8 M3 hex nuts
x4 30 mm M2 brass spacers
x10 M3 plastic screws
(optionally) 1x Linaro LAA Support Base
Mini Screen:
OLED
OLED protector
x2 M3 screws
x2 M3 hex nuts
Supports for the SIB
The first thing we want to do is to assemble the supports on the SIB so that it can stand safely.
This is what a SIB looks like, specifically an hardware revision 3 board:
We want to add the longer 30 mm spacers at the bottom. But first we want to add “feet” to the spacers, which will be the plastic M3 screws.
Linaro LAA Support Base
If you have Linaro LAA Support Base make use of it to place your 30 mm spacers. It will be very easy to place the SIB on top and fix it.
The 30 mm spacers will need to be screwed on the other side of the board with the 17 mm spacers or with an hex hut, as you can see here:
In the next photo you can see where you want to put 8 of the supports (the other two will be just afterwards):
For the last two 30 mm spacers we will be using hex nuts, these will be placed at the front of the SIB.
Make use of a hex wrench (see photo) to make sure everything is properly fixed.
At this point we want to add the M2 30 mm spacers underneath the USB plugs. These are important to avoid for the SIB board to bend and break when someone wants to plug USB connectors to them.
As you will see the holes are between the USB plugs, making it harder to mount the supports. Your fingers will be too big to place the hex nut between the plugs. The best way would be to make use of a hex wrench that’s also magnetic, making the nut stick on the tool. Otherwise a trick is to take some tape and put it around the wrench, then we want to attach the hex nut to it. You can see it here:
You can put the hex nut in front of the hole between the USB plugs and then screw the spacer from the other side.
That’s what you should be seeing after mounting these 4 supports.
Use the hex wrench to make sure all the M3 plastic “feet” are properly screwed.
SIB feet
The M2 30 mm spacers will have smaller M2 plastic screw “feet”. In order to touch the ground they need to NOT be fully screwed. This will ensure to not bend the SIB board when you try to connect something on the USB plugs.
OLED Screen
It’s now time to mount the OLED screen. There is an optimal sequence of steps to mount it easily.
First, we want to insert the OLED screen component on the 4 pin connector.
Then we want to put the protector in front of the OLED.
Protector
The bottom part of the protector will go on the other side of the SIB board.
Finally, we want to put the screws with the nuts.
Temperature Sensor
Mounting the temperature sensor is straightforward since there is once one place it can go and can’t be inserted in the wrong way.
Sensor
The sensor itself is at the end of the wire, you can decide where you want to place it and read values from.
Adding the MIB
At this point the SIB is ready to have the MIB placed on top.
Before that, you can optionally add supports for the DUT board on the MIB. In order to do so you need to find appropriate spacers and the hex nuts and screws to fix them. Double-check where the holes are.
Spacers
The spacers are probably going on the top of the MIB.
We will now proceed in placing the MIB on the SIB supports, making sure that the big connector in the center connects to the plug on the SIB board.
Once we put the hex nuts we should get here.
We can now put the Jumper and set the main voltage to 3.3V.
DUT: Raspberry Pi 4 Model B
We can now mount the Raspberry Pi 4 Model B on the LAA.
Just pay attention to how you connect it. The Raspberry Pi needs to be placed as indicated on the MIB itself, facing down.
And at this point, we want to connect the LAA to the DUT via various cables and connectors. Which cables are required depends on which DUT you have. In our case, we’re considering a Raspberry Pi 4 Model B and you can find all the info on how to connect it here: Raspberry Pi 3 Model B+ and 4 Model B