Electronics Maker Christmas stocking fillers list

It's that time of year when my family ask me for ideas of presents for Christmas and my Birthday.  (both December)

With electronics bits being a bit specific/esoteric I stopped trusting that if I said what I wanted they would get me the right thing after I gave my wife a link without a description for a new CPU.
By the time she clicked it the link redirected to a few screws.  Luckily she checked before buying and I was able to get her the alternative link.

So, these day I provide a wish list email with more items than I expect to get so I still have the surprise when I open the packaging as to what they give me.

This year I've decided to share the list.  This list may be added to as I think of more things.
Before you ask things like Arduinos, Raspberry Pis, Circuit Playground boards are not on this list as these are things I have usually already got a stash of.  This list is for the other bits that make those things useful.  The kind of things it would be useful to have before starting a project but may not have already or may have run out of.

I try to keep the items to less than £20 so for many these are good stocking fillers.


USB Current Tester - £4.50

I buy random items off the Internet and for batteries and USB PSUs I want a way to see if they meet their stated ratings.

Heat Resist Soldering Mat - £9.90 - £15.00 - There are bigger and smaller ones out there as well.
I have a regular A3 cutting mat but like this because of the different compartments to keep bits as I regularly drop screws and tools and hope this will help me be more organised when working on something.

Crimping Tool with 450Pcs Connector - £23.99  

I sometimes use buttons with spade connectors and at the moment I solder the wires on which is not ideal.  Want to start using the correct connectors for the correct job and not just bodge something that later causes a headache that I have to fix.

Anker 4-Port USB 3.0 Hub  - £10.99  
Sometimes for the Raspberry Pi I need to burn multiple SD cards.  The great Etcher will burn multiple images at the same time so with this I can add 3 more to be burned in parallel (it's not 4 as I lose a port to connect it)

Adafruit Hook-up Wire Spool Set - 22AWG Stranded-Core - £17.93 

Starting to try and be more organised so like the idea of this set of wires.  I have loose spools of wire around the place so the plan is to replenish the spools when they run out.

20pcs Multicolored Dupont Wire 40pin Male to Female, 40pin Male to Male, 40pin Female to Female Breadboard Jumper Wires  - £5.95

Saying that I still do breadboard stuff so it's always good to replenish the stock of Dupont jumper wires.

2.54mm 2x20 40-Pin Female Pin Header Socket Connector Strip 10 Pcs - £1.94

Having recently committed a project to an actual prototyping board rather than using a breadboard I want to do more of that for my Raspberry Pi projects so need a bunch of 2x20 female connectors to hand.  Last one I used I 'borrowed' form a Kickstarter I backed, so that's now an incomplete kit.

SanDisk Ultra 16GB microSDHC Memory Card + SD Adapter - £5.99

I'm always looking for microSD cards, so every year I add them to the stocking filler list.

They're small and I'm clumsy so replenishing stock is an ongoing activity. 

Codebug - Flashing LED tree made with conductive paint

Last year I made some conductive paint using this Instructable.  For me 50:25 by weight, paint to graphite powder works great. Make sure to stir in slowly otherwise the graphite powder will fly.
With this mix the paint is easy to apply yet has good conductivity.
It worked great and I used it at a Raspberry Jam to make flashing LED eyes for Halloween.

Since then the paint has been abandoned until my eldest daughter mentioned she was making circuits in school yesterday and I said I'd try to make them flashing LED Christmas Tree pictures.
This got a thumbs up from my daughters so the pressure was on.

Using Inkscape I drew a simple Christmas Tree with a place to put 7 LEDs.
Nice and simple and easy to print on A4 card.  I made the baubles the shape of a physical LED so you can see which way to place the LEDs on the sheet. All the negative (ground, cathode) sides in the middle making it easier to connect all to GND later.

PNG Version.

Links to PDF and SVG 

With the drawing done I added the LEDs.  6 to the green tips and a yellow one in the star.  I had 2mm LEDs to hand so that's what I used.  For the real thing I plan to use 5mm as the effect should be better.

I found pre-bending the LED leads at right angles so they are pointing down when in places made it easier to  get the LED to stand up at the front.  I also made small holes using a pin to push the LED leads through.  It's hard to push LEDs through 300gsm card as the leads don't have a point.

Once this was done I turned over the card.  Left the ground side for each LED pointing down and turned the positive side (anode) out at right angles pointing to the edge.  Once done I used a small piece of tape to keep the LEDs in place.
Tip.  Push the leads down to they push against the card. It's means the leads lie flat making them easier to hold on with just paint.

Back of the card

As I mentioned the conductive paint had spent the last year drying so was a bit sticky meaning the paint job is less than smooth.  I have since revived the paint with a little bit of water so for the kids it should be much easier to paint.

The bar down the middle is the ground tied to all the LEDs.  The other lines are for the positive side of each LED.
If you want all wires to be at the bottom then you may have to adjust the SVG in Inkscape to only print one Tree per A4 landscape card.

To test I thought I'd use a Codebug I got in the Kickstarter and hardly used it since. They are no on sale at CPC Farnell
With the help of Twitter people (I didn't declare the legs as outputs at the top of my code) I put together the following program. Link to CodeBug site for project

CodeBug code

Once all this was done the LEDs flashed. Yeah!.

For this project I wired up the LEDs so the top and bottom on one side are paired with the middle one on the other side and vice versa and the star LED on a leg of it's own.
This only uses three  (3) legs on the CodeBug,s o the 4th one (3) in the code is redundant.  I just left it in there in case I can figure out a more exciting way to use 4 outputs to flash 7 LEDs.

Very Short video of the final tree.

Next I want to wire up to a Raspberry Pi to enable interactive input and independent control of all the LEDs and maybe play a Christmas tune as well.

Sidenote; Some might be asking where the current limiting resistor is.  It's the paint.  The conductive paint has a higher resistance than wire and so it is acting like the current limiting resistor.

Mini Wireless Keyboard/Touchpad and Nano USB Wifi Adaptor that works with Raspberry Pi

As part of my Christmas presents I got a couple of bits to go with my Raspberry Pi.
As I sometimes take the Raspberry Pi out and about I wanted a mini wireless keyboard/touchpad to pack in my box of wires.

I heard good things about the Rii 2.4GHz Wireless Mini PC Keyboard Touchpad so added it to my wish list. I plugged in the dongle to the Raspberry Pi, turned on the keyboard and it worked first time. No problems at all.  I read some comments that the range is very short. I'm getting about 3 metres from it as I haven't tested any further.  Very happy. Keys are big enough for me to use comfortably and the main keys are all in the expected places.  It also has a laser pointer built in if needed.
Also, the extra function keys beyond [F8] are at [FN],1,2,3,4 so you do get the full 12 functions keys but only the first 8 are shown.
The one I received was in a plain white box.

I also got the Edimax EW-7811UN Wireless 802.11b/g/n 150Mbps Nano USB Adaptor.
Using Raspbian it worked first time with no additional drivers required.

With the 2 of these plugged in I have a full functioning compact computer with only the power and HDMI coming from it.

So, when I'm logging in remotely using Xming and Putty I can put the Raspberry Pi where ever there is a spare socket and work away.

I also got  the beautiful Pibow Colour Raspberry Pi Case.  and the Adafruit Pi Cobbler Breakout Kit. So, very happy with the presents.

Note: Links are to Amazon UK stores where mine came from.  My wife has learned that the best thing is for me to email her actual links rather than having me expect her to known what I'm looking for.
One year a link went from being a processor to a couple of wires. luckily she checked with me before buying.