This page has a list of UK-based online sellers of electronic components, almost all stock Arduino and Arduino-compatible components. I've purchased something from almost all of these at some point or other and have enjoyed a good level of service. Adafruit is not UK-based but is included because, like Sparkfun, a lot of their components are sold in the UK. Adafruit list the distributors on a product-by-product basis. They also tend to have videos and tutorials for their products accessible from their store page. Prices vary, shops have sales, some prices include VAT, some don't and so on.
Your favourite online marketplaces like Amazon, Ebay and the like also tend to feature some stuff, sometimes at low low prices, sometimes seriously overpriced.
Check specifications carefully before ordering costly items. Check the operating voltage and make sure it is compatible with your Arduino. If you are buying a sensor, check its precision, accuracy or margins of error. It's worth reading an online tutorial or watching a video about the component to be confident that you'll be able to use it as you expect.
In alphabetical order,
- Cool Components
- Digital Means
- Hobby Components
- Proto-PIC Electronics
- Robot kits
- SK Pang Electronics
- Technology Will Save Us
- Unmanned Tech Shop
A lot of the breakout boards and shields are sold without headers. You will need to solder on some headers if you want to use them with your solderless breadboard and Arduino. The spacing between the holes (the pitch) is usually 0.1in and headers are not too expensive. If you completely avoid soldering, you limit the kind of stuff you can use.
If you are taking the plunge with soldering, you'll want to read up a little, watch a few videos and take the safety advice seriously. I'm no expert with soldering but get by happily on a cheap 40W kit (under £10) with tips that can be replaced. I use a brass sponge for cleaning the tip but a wet sponge will do the job fine. It's worth getting some cheap protoboard or veroboard and having a practice first with some LEDs, resistors and headers in a few simple circuits to check you are happy rather than trash an expensive shield.
There are lots of these for sale and they range in price from around £20 for a very basic kit with a cheap clone Arduino to approaching £100 for kits with dozens of components and booklets of projects that use these components. These are not a bad way to start. The kits often include some fairly high value items, like flex sensors and soft potentiometers. These are cool items but you might not use them much beyond a few variations on the project in the booklet that came with the kit.
The Arduino board is the main piece of equipment. The Arduino Uno and the Arduino Leonardo, or boards based on their designs are a pretty good bet and are under £20 for the genuine Arduino. Some clone boards are cheaper, perfectly legal and most work absolutely fine for simple projects. Some are at least as good as the original boards, though some use cheaper components or are produced in higher volumes.
It's worth comparing the contents of a pre-made starter kit with the price of working out your own basic version. Whether you choose to get your parts separately or as a kit, the following should help you decide which is best for you. You could learn a lot by being limited to something like the following 'Essentials' kit and still wanting to find new ways to program the interactions with the parts. A box is not mentioned below but needed to contain your stuff - you probably have something suitable already.
|Arduino Board||Likely to be the most expensive item in the kit. See the section above for more on how to choose. Not all boards are sold with a USB cable. This will add to your total cost if you need to get a separate one. Check that you don't already have a spare cable with the right connectors.|
|Mounting Plate||You probably want something to mount your Arduino onto. Usually these are a piece of acrylic with some holes laid out for you to screw the Arduino into. Screws and standoffs are usually provided. These vary a lot in price and all of the types I've used are fine, including the ones at a few pounds. Alternatively, buy some M3 threaded nylon standoffs along with your parts, and glue them to a piece of acrylic or plastic you already have.|
|USB Cable||If not provided with the board. Check the connector to the Arduino carefully. There are several types here and you need the right one for your board.|
|Solderless breadboard||Shop around for these. You want one that has the 5v and GND rails on at least one side. They usually have a self-adhesive base and you can stick them onto your mounting plate.|
|Jumper Wires||One of the more costly items to purchase. If someone at home already has the right type of wire, you could make your own. If not, a selection of long and short jumper wires is vital.|
|LEDs||The first thing people tend to make is a circuit with an LED. You use LEDs as indicators in a lot of projects. Two colours gives you a good start. These are often sold in packs of 10 with a set of the appropriate resistors (usually 330ohm) and at reasonable prices.|
|Resistors||10Kohm and 330ohm resistors are essential. You'll want around 10 of the 10kohm resistors and one 330ohm resistor for each LED. If the LEDs you get come with a different value resistor, it would be worth having 10 of the 330ohm for other purposes.|
|Pushbuttons||Buttons are your user interface. The clippy parts on the bottom make it hard to fit them into breadboards. They are great when you solder them to a printed circuit board though. Around 4 - 6 buttons will do for most purposes and would be a good start. Mini-buttons are harder to press but are easier to stick in a breadboard. Remember that this is your experimenter's kit - perfect buttons are for finished projects.|
|Buzzer||Check it's okay for 5V. You'll want a bit of noise now and then.|
|RGB LED||One or two of these is good. This gives you access to a full range of colours. Most boards can drive 2 of these at a time. There's no point having more in a start kit. There is a lot of interesting programming that can be done with the RGB colour system.|
|74HC595 Shift Register||One of these would be great. It's an integrated circuit that allows you to control 8 components using 3 pins of the Arduino. Excellent for working with binary in a circuit.|
|TMP36 Temperature Sensor||A reasonably priced sensor to get used to the idea of working with sensors.|
|Trimmer Potentiometer||A couple of 10K linear trimmer potentiometers would be useful. These aren't too expensive but the pins are fragile. More robust versions tend not to fit in a breadboard.|
|Photoresistor||This is your light sensor and another interesting way to interact with the real world.|
Some things aren't overly pricey and if you have something in mind that involves the following, then you might also want to include them in your kit.
- Logic Gate ICs
- Rotary Encoders
- 7 Segment 'Bubble' Display (Under £2, retro Computer Science joy)
One of the following items would be a bonus for a start kit. Most of the pre-made starter kits include a range of other things. Some of these things (like a soft potentiometer, a flex sensor, a servo, or the single motor and related parts) are interesting to set up but tend not to get much additional use. Some things that you are likely to use in a range of circuits or which provide the richest blend of electronics and programming are shown in the table.
|LCD||A basic 16x2 Hitachi-compatible LCD is a good way to check the output from a circuit. This will allow for character output only.|
|Infrared receiver & remote control||These are sometimes bundled with starter kits and are cool to play with. An old remote control has a decent chance of being usable with a cheap infrared receiver - approx £1.50. An excellent way to create a large number of inputs for your circuit.|
|LED Bargraph||Usually just 10 small LEDs built into a unit but with their own separate pins.|
|LED Matrix||Usually 8x8 LEDs - you'll need some 8x1K resistors.|
|RTC||Real-time clock. You'll be talking about a circuit board here, with a crystal, coin cell battery holder and integrated circuit. Check if the headers are soldered on for you.|
|OLED Screen||These are about the cheapest way to get flexible graphical output. There are lots of ways they can be used at the core of a project and they are great for outputting debug or test information.|