How to Assemble the Fish Dish Add-on Board for the Raspberry Pi

Take a look at most Raspberry Pi add-on boards on the market and you’ll find endless full-size, feature packed examples ready for robotics, I2C, XBee and more.

Whilst these boards offer great functionality for experienced ‘makers’, a part of me thinks we’ve forgotten the reason the Raspberry Pi came about – “To advance the education of adults and children, particularly in the field of computers, computer science and related subjects“.

A solution is here – enter the ‘Fish Dish’ – an add-on board for the Raspberry Pi targeted towards younger beginners, but also suitable for the more experienced to hack away with.

In this post I’ll show you how to solder the board, and cover some code in another post later on…

What you need

Main Parts:

Fish Dish (Buy from the ThePiHut.com)
Soldering iron
Solder & soldering sponge
Wire cutters

Optional:

Helping Hands
Long-nose Pliers

Open the Pack

In your Fish Dish, you will find:

The Fish Dish PCB
GPIO Header
Buzzer
Switch
Rubber foot
3 x LEDs (Green, Yellow and Red)
3 x 330 Ohm resistors (the 3 small beige ones)
1 x 10k resistor (the one with the orange stripe)
1 x 1k resistor (the one with the red stripe)
A few stickers!

The Fish Dish parts laid out

How to Assemble

Step 1 – Solder the GPIO header

Push the GPIO header pins through the PCB so that the metal pins are on the same side as the instruction text (LED1, LED2 etc – see the picture below). Use something to hold it in place – I have rested the header on the bottom of my Helping Hands here:

Fish Dish solder GPIO step 1

Solder one corner first, then solder the opposite corner at the other end of the connector. This will then hold the header in place while you solder the remaining 24 pins:

Fish Dish solder GPIO step 2

Once you’ve soldered all of the pins, we’re ready for the next step:

Fish Dish solder GPIO step 3

Step 2 – Solder the 330 Ohm Resistors

In this step, take care to make sure you solder the resistors in the right spots. It’s pretty easy though thanks to the size, colour and stripes – so you should be fine.

First we will solder the 3 x 330 Ohm resistors first (the 3 smaller beige ones). Although it doesn’t matter which way round we fit them, let’s keep all the gold stripes to the top to make it look smarter.
Poke the legs of the first resistor through the ‘R1‘ holes as shown, and push through so the resistor is tight against the board.
Use something to hold the resistor in place – I’m using a crocodile clamps from my Helping Hands unit:

Fish Dish solder resistors step 1

Once everything is secure, solder the legs into place:

Once both legs are soldered, snip the remaining legs off with your wire cutters:

Fish Dish solder resistors step 3

Repeat this step for the next 2 resistor slots (R2 and R3), using the remaining 2x beige 330 Ohm resistors.

Step 3 – Solder the 10K Resistor

The 10k resistor is one of the larger blue resistors. Specifically, it’s the resistor with the ORANGE stripe (NOT red, that comes next).

This resistor fits into the R4 slot (labelled “10K”)
The process for fitting this resistor is the same as step 2, which should leave you with this:

Fish Dish solder resistors step 4

Step 4 – Solder the 1K Resistor

The 1k resistor is also one of the larger blue resistors. You should only have one left now, which should be the resistor with the RED stripe (NOT orange, we just used that).

This resistor fits into the R5 slot (labelled “1K”)
The process for fitting this resistor is the same as step 2, which should leave you with this:

Fish Dish solder resistors step 5

That’s the resistors all done!

Step 5 – Solder the LEDs

Let’s confirm a few things before we start on the LEDs…

LED Order

Here’s what the LEDs need to look like when it’s done:

…Which means the LEDs need to go in the following slots:

Green = slot ‘LED1’

Yellow = slot ‘LED2’

Red = slot ‘LED3’

Polarity

You must make sure the LED legs are the right way round (correct polarity). The longer leg on the LED is the positive leg. Another way to check polarity is to look for a flat section on the LED plastic, that leg will be the negative leg.

The Fish Dish PCB shows you where the positive and negative legs need to go (positive in the top hole):

Solder the LEDs

Start with the green LED in slot ‘LED1‘
Push the legs through the holes in the PCB (remember: longer leg into positive)
Hold the LED in place (I used a crocodile clamp):

Fish Dish solder LEDs step 3

Solder the legs into place, and snip off the excess like we did with the resistors:

Fish Dish solder LEDs step 4

LEDs done!

Step 6 – Solder the Buzzer

Just like the LEDs, the buzzer also needs to be fitted the right way round. Luckily the buzzer has a long positive leg like the LEDs, but is also well marked on the component itself:

The buzzer goes into the slot called ‘BUZZ’
The negative and positive holes are clearly marked (positive to the left)

Fish Dish solder buzzer step 2

Push the buzzer legs through the holes so that the main black body is the same side as the LEDs (remember to check the right legs are going through the right holes)
Solder the two legs and snip any excess as before:

Fish Dish solder buzzer step 3

Step 7 – Solder the Switch

The switch has no polarity, but you need to make sure the legs are in the right place or it won’t be connected to the circuit properly. The switch is very slightly rectangular which helps you work out how to place it.

First, take a look at the picture below for reference on the switch position:

Fish Dish solder switch step 1

Just as before, it’s simply now a case of soldering the 4 legs in place, again, remember to solder diagonal opposite legs first to set the switch in place:

Fish Dish solder switch step 2

Step 8 – Attach the Rubber Foot

The last step is the easiest. A small rubber foot is included to rest against the composite connector, so that when you press the Fish Dish button, you don’t bend or snap the board/connections.