Ordering Electronic Components

The designer Phil has made lists of components for each device from via a company DigiKey in the USA. Delivery from DigiKey to UK usually takes 2 to 3 working days from ordering, and is free for orders over £33.

The easiest way to get components is to order them all from DigiKey. However it is possible to save between 25% to 40% of the total cost of a device by ordering some of the components from online marketplaces like AliExpress, Temu, or similar.

On this page are the following:

  1. Ordering from DigiKey
  2. Saving (a little) money on DigiKey Orders
  3. Saving (a lot of) money by ordering on online Marketplaces

Ordering from DigiKey

Visit the “Phil Phil Atkin” page on PCBway to see all his designs:

Click on the device you are interested in. Then scroll down to find a link in text body to the “DigiKey parts list” or “Shopping list, and click on it.

  • You will then open a list Phil has made and shared on DigiKey, as shown to the right, this is known as a “assembly” of parts.
    • Note: Ignore the details of the name of the list. Shown circled in Red. These are rarely updated by Phil and are sometimes out of date. e.g. Currently (7/26) the “pippyg 4.04” list is named “PIPPYG 4.1 – experimental SD card”
  • By default, Phil’s lists usually include enough components to make 5 devices (The Nano list makes 10). To order more, change the number in the “Assemblies” box in the top right. Shown circled in Green on this image. For example to order enough for 10 devices change it to 2 (2 assemblies of 5 =10), and click outside the box to allow DigiKey to recalculate.
    The list is read only, so you cannot change individual quantities, or delete line items, at this stage, but don’t worry you can later.
  • The price will change to show the total price, and the price per “assembly” (of 5). Due to quantity discounts the price per assembly generally decreases as you order more.
  • Leave the “INCLUDE ATTRITION” under “Assemblies” unselected, as this simply adds 10% to some quantities.
  • When happy, scroll down click “Add to Basket”, shown circled in Blue. Then select “New Basket” or add to “Current basket”.
  • When viewing your basket, you can now change quantities or delete items.
  • It is well worth clicking into the Quantity boxes (shown circled in green), as this shows the “Price Breaks” by quantity. It is sometimes only a few pennies more to increase the quantity, and sometimes cheaper to buy more!
  • Phil often includes a “DIODE STANDARD 100V 200MA DO35” to poke solder paste out of the mic hole. But I always delete it, and use a pin instead!
  • When happy, click the red Checkout button and follow the process.

When you get to the Shipping page make sure the default “UPS Worldwide Saver 2 Day(s)” is selected as this is “DDP”, where the Duty and customs paid by DigiKey

After payment, you might think your order is complete and being processed. However there is one more step:

  • Check your email, and there should be one from DigiKey, asking you for more details. Click the link in the email.
  • This leads you to a DigiKey page with a few regulatory questions:
    • Select the box to say you will not be reselling the components in their current form.
    • I usually select “Consumer electronics” > “Audio Devices” then add “Bat detectors”
  • Once the form is submitted and reviewed by DigiKey, then they start processing you order and it usually arrives in 2 to 3 working days.

Saving pennys on Digikey orders

Having built many Pipistrelle detectors and run lots of workshops, we have actively tried to seek out the cheapest components on DigiKey. We maintain our own DigiKey lists, so as of early July 2026 the price comparisons between Phils and our lists are:

Please feel free to reuse our list on the links above, if they save you a few pennys.

Please note: Circuit boards, component list and DigiKey prices do change. So please do check our lists against Phils, and most importantly the board you are ordering, before committing to buy from DigiKey. And PLEASE do let us know if you spot any changes needed to our lists.

Saving even more via online market places

It is very possible to save considerably on DigiKey prices by shopping direct with online marketplaces such as AliExpress, Temu or Alibarba.

However you are building your first Pipistrelle detectors we STRONGLY recommend buying everything from DigiKey using the supplied lists. In this way you ensure you get the right parts that will fit correctly, and can familiarise yourself with them, so you buy from other places with more confidence.

For other components we tend to use AliExpress exclusively, as we have found they have the biggest range of suitable electronics at good prices, with free delivery on most things over £8.

So as of early July 2026, in order, the biggest savings you can make per device are:

We would strongly recommend reading up on techniques on AliExpress to drive these even prices significantly lower before you order. Please see this page for details, then come back here

Prices below were correct in early July 2026

Raspberry Pi Pico

The single biggest saving is to buy clone Picos. Please ensure you ONLY buy RP2040 Pico 1 with a microUSB (mUSB) connector.

Our favourite supplier of reliable Picos is HZWDONE Store on Aliexpress, their “Raspberry Pi Pico Board RP2040 PICO W Dual-Core 264KB ARM Low-Power Microcomputers High-Performance Cortex-M0+ Processor” mUSB variant is often reduced below £1.40 on bundle deals. I buy bundles of 6 or 15 at a price of £1.15 each, or cheaper.

AliExpress price each:Retail priceTarget price
(via bundle deal)		Best ever price paid
Pico mUSB Clone£2.09£1.15£0.84

Do NOT buy:

  • Pico 2 – Phils code will not run on Pico 2
  • Pico W (Wireless) – Far more expensive, and the wireless part will not be used and simply drain batteries faster.
  • Pico with USBc connector – expand below for details of why
Click here to understand more about the issues with USBc Picos

While Picos with USBc might seem tempting, there are no officially made USBc Picos. Unfortunately there is a manufacturing flaw with all of the clone USBc Picos which mean:

  • “some” have worked with Apple devices on iOS, some Picos do not. It seems random.
  • None have ever worked connected to an Android device (without micro surgery on the Pico).
  • Most seem to be recognised by Windows, Linux and Mac, to allow them to be flashed.

You “could” use USBc Picos if you NEVER plan to connect the it to a mobile device as a ultrasound microphone. For instance they “could” be used on a:

  • BatSynth v1,
  • Pipistrelle or PippyG that you will NEVER connect to a mobile device as a ultrasound microphone

Speaking plainly, the best advice is to keep it simple and just buy mUSB Picos!

Note: You may find references to USBc Pico’s on Phils website, or in his Social media posts, however these usually relate to early experiments, and are out of date. It was later testing that found the problems with USBc Picos.

Click here to learn more about the details of USBc Pico testing

In November 2025 Phil reported success with clone USBc Picos, build into Griffs, connected to iPhone.

We immediately ordered some as this would make cable connections much easier. On arrival the first were built into Griffs, and it immediately became apparent that the USBc Picos did not connect to Android devices.

After much testing of different cables and devices, Phil realised realised that the two “pull down” resistors on the Pico are factory fitted at 90 degrees the wrong orientation. As shown circled in red on the first photo. i.e. Horizontal rather than vertical.

John Mears, the genius behind the BatGizzo App, went on the prove this by:

  • “I unsoldered both of the tiny SMT resistors and immediately lost them.
  • I soldered a pair of wire ended 5.1k resistors to the upper pair of pads, which have have tracks to CC1 and CC2 on the USB C connector. The other ends are wired to GND.
  • Sure enough, it works correctly with the cable and connectors in all orientations with:
    • My decent spec Android phone.
    • My very cheap and low spec Android tablet.
    • My linux desktop computer.
    • My windows laptop”

This is shown in the second photo.

While is “may” be possible to resolder these resistors in the right orientation, they are tiny (0402) and difficult to do, and hence probably not worth the effort. Just buy mUSB Pico!

Battery Holders

The second biggest saving is on battery holders, however care is needed to ensure you get ones with pins (NOT wires).
While 3 x AAA holders with pins are relatively common, 3 x AA holders are rare on AliExpress. It’s usual to buy both these in 10’s, but for simplicity the table shows the unit price of each individual battery holder.

AliExpress price each:Retail priceTarget price
(via coins & coupons)		Best ever price paid
AAA x3 battery holder£0.45£0.39£0.22
AA x 3 battery holder
(No free postage)		£0.74£0.62£0.62

Audio Jack

Savings are smaller on these, and you have to be careful of quality. Some cheap jacks are very tight at first.

The key part number to search on AliExpress is “PJ-320A” Patch type

It’s usual to buy these in 100’s, but for simplicity the table shows the unit price of each individual PJ-320A Audio Jack.

AliExpress price each:Retail priceTarget price
(via coins & coupons)		Best ever price paid
PJ-320A Audio Jack3.3p2.5p£0.00 !

There are also “fancy” coloured versions, or ones with metal end rings, if you are feeling flash.

Slide switch

Smaller but significant savings here. Quality can be lower, so be sure to test the completed board switch using a loose battery pack, before you solder one on. We are on about a 4% failure rate with these cheap switches.

The key part number(s) to search on AliExpress are “MSK-12C01” or “CUS-12TB”

It’s usual to buy these in 100’s, but for simplicity the table shows the unit price of each individual MSK-12C01 slide switch.

AliExpress price each:Retail priceTarget price
(via coins & coupons)		Best ever price paid
MSK-12C01 slide switch4.1 p3.6 p3.6 p

If you shop around, you can find MSK-12C01’s with black switches, or ones with longer switches (2.5mm vs the usual 1.5mm). We have not tried these variants yet.