Sourcing hardware

You will need to source a range of parts to build your BODAQS data logger. A small selection of common tools is also required.

These materials are for the BODAQS A8 logger

The following materials work for the BODAQS A8 logger, currently version 1.0. If you are building the Prototype F logger, start here

A complete Bill of Materials, including links, is at the end of this section. If you prefer, you can get the Bill of Materials as an Excel spreadsheet

You can buy a PCB or kit directly from BODAQS.net

Printed circuit board

The printed circuit board (PCB) is custom-designed for this project. It is obtained by ordering it from a PCB fabricator. You can also get it from me.

Obtaining the PCB fabrication files

Go to the ‘releases’ page in the BODAQS github repository here and download the latest PCB fabrication package. The package contains all the files you need to order an assembled PCB from JLCPCB.

Ordering PCBs on JLCPCB

First, create an account at JLCPCB (or log in if you already have an account). Then Select ‘order now’ from the top right of the home screen.

Select “Add gerber file” and navigate to the *.zip file in the fabrication files package. When the file has uploaded, a picture of the PCB should appear in the box.

In the ‘High-spec Options’ section below the PCB picture, set ‘Specify Stackup’ to ‘Yes’ and then select ‘JLC04161H-7628’ from the list of available layer stackups.

Scroll down to the bottom of the page, leaving the other settings unchanged. Click the ‘PCB Assembly’ slider ON. A set of new options should appear below. Set ‘PCBA Type’ to ‘Standard’ and leave the other options unchanged. Click ‘next’.

A picture of the PCB should appear. Click ‘next’.

Select “Add BOM file” and navigate to the *-BOM.csv file in the fabrication files package. Select “Add CPL file” and navigate to the *-all-pos.csv file in the fabrication files package. Click ‘process BOM and CPL’.

You will be presented with the Bill of Materials and Component Placements. Make sure that all the checkboxes in the Bill of Materials ‘Select’ column are checked before proceeding. Click ‘next’, and again on the placements page.

Out of stock parts

If a component’s checkbox is not selected in the Bill of Materials, it is usually because the part is out of stock. If the part is a resistor or capacitor (designators beginning ‘C’ or ‘R’), you can search for alternative parts and accept any in-stick parts JLCPCB offers. For other parts, don’t make substitutions unless (1) you are completely sure you know what you are doing, or (2) you talk to me first.

Review the quote and select an appropriate product description (this is needed for shipping paperwork). Research/Education/DIY/Entertainment => DIY hobby circuit board is a good option. Select ‘save to cart’.

Select ‘secure checkout’ and complete checkout details.

Minimum order quantities

Minimum order quantity for custom PCBs (from JLCPCB) is 5, which is more data loggers than most people need. With the A8 design, all the hardware is baked into the design *unlike the Prototype F, which uses a plug-in development board). That makes ordering 5 a little pricy.

If you dont want the cost of 5 PCBs, consider pooling with your friend or buying a PCB or kit from me. Buying stuff from me is going to be more expensive on a per-unit basis, because my time is valuable too, but it could make getting the parts you need a lot simpler.

Electronic parts

0.96” OLED display

These displays, based on an SSD1306 driver chip, are a commodity item and many vendors sell functionally equivalent versions. They do vary slightly in the physical dimensions of the board however, and some versions may require minor case modifications to install. The case is designed around a HS96L03W2C03 module, like this one but if the description says HS96L03W2C03, you should be good to go. Lots of other similar modules can work too - if you buy something different, don’t worry – it can probably be installed with only minor modifications.

Nintendo 2DS replacement button pads

This is another commodity item available from many vendors on AliExpress, Amazon and Ebay, like this one. Note that the case design specifically requires 2DS parts - other controller parts won’t fit. Search for “button pad 2ds”.

Li-ion battery

The BODAQS A8 uses a 3.7V Li-ion polymer battery pack with JST-PH 2 pin connector. Li-ion polymer batteries are widely available from a variety of sources. For our purposes, all are equally good. However, make sure that:

• The battery’s maximum dimensions are 65mm x 55mm x 7mm
• The battery’s capacity exceeds about 1000mAh
• The battery comes with a 2-wire JST-PH connector. Some batteries are sold with JST-XH or SM-2P connectors, which are not the same and will not fit.

Some sources for suitable batteries:

• In Australia, Altronics have the exact battery I use.
• In the US, Sparkfun has one that looks the same.
• In the EU, Kiwi Electronics looks like it should work.
• And of course, AliExpress has numerous options, like this model 524261

Always check polarity before connecting

Not all battery connectors are wired with the same polarity. Check and double check that the positive and negative leads from your battery are correctly oriented. If they are not oriented as shown, gently lift the tabs on the plastic connector housing with a needle or the edge of a craft knife, withdraw the leads and re-install them in the correct positions. If the leads are not color-coded, then test the cell with a multi-meter to determine positive and negative.

Do not connect a battery with the incorrect or unknown polarity as it will probably damage the development board.

Header socket

Header sockets are standard electronic parts for making plug-in connections to a PCB. This one connects the OLED display and needs 4 sockets in 1 row, 8.5mm high and 2.54mm pitch. Longer sockets can be cut to size. You should just add these to the order from wherever you get your battery or other electronic parts (links in the table above).

CR1220 button cell

A button cell that powers the logger’s real-time clock (RTC) when the battery is disconnected, allowing it to retain the time. These are available in hardware stores, pharmacies and supermarkets.

MicroSD card

You will need a MicroSD card to record log files and store the logger’s configuration file. 16GB is sufficient - even a large log file is only a few tens of MB. Likewise, super high performance is not essential. Any modern name-brand MicroSD card should perform adequately.

Connectors

The BODAQS A8 logger has 4 external connectors: two for analog inputs, one for I2C and one connector for a handlebar-mounted switch and GPS connection. All the connectors are identical 6-pin metal M8 circular connectors, Amphenol part number M8AS-06PMMR-SF8001.

You can get original Amphenol connectors from Digikey or other major online electronics suppliers. You can get copies on AliExpress from various vendors, like this one

Name brand or generic?

One of the advantages of M8 circular connectors is the availability of low-priced clones on AliExpress and similar marketplaces. These are generally fine, with one caveat: buy both the connector and the matching wire tail from the same vendor. There is some variation in pin diameter and the dimensions of the plastic inserts between the originals and the clones, and between different clones.

Plugs for the connectors.

It goes without saying that these need to match the connectors. It is easiest to buy plug assemblies with sealed wire tails and join you sensors on. The Amphenol plug assemblies I recommend are Amphenol 8A-06AFFM-SL7A01, available from Digikey. If you’re going the AliExpress route, get them from whoever is supplying your connectors, and to match - or go elsewhere.

For intermediate connections, I favour generic plastic M6 or M8 push-in connectors, sold on AliExpress (for example, here. They are low cost, compact, waterproof, and convenient when you want removable sensor sections or Y-connection branches.

Their weakness is that they do not lock by themselves. You should be careful that cable movement (from turning the handlebars, say) cannot pull them apart, and either duct tape them together or [use this 3d-printed lock].

Read the section on Wiring and connector tips before purchasing your plug assemblies.

Shrink sleeve

You will need shrink sleeve for covering soldered joints. Read the wiring and connector tips section to decide what you need - at a minimum, you will probably require some 2.5mm shrink sleeve for covering soldered joints where you connect your sensors to the plug assembly. If you are making y-connections you will also need 10mm adhesive lined shrink sleeve. You can buy this at good hardware stores and electronics suppliers.

Caulking silicone

You will need caulking silicone for fitting the acrylic cover to the logger case. It is also useful for waterproofing y-connections. Use neutral-cure silicone only if you are using it for waterproofing wiring. You can buy this at most hardware stores.

3D printed parts

The logger case can be printed on any modern 3D printer. You can:

• Print it yourself (or have a friend do it)
• Have it printed by a local business
• Buy one from me as part of a parts kit
• Order one from JLC3DP (the 3D printing sibling of JLCPCB).

All the print files are available here and here. (The Fusion CAD model of the case is in the ‘f3z’ directory).

Parts required

There are two variants of the case design. The main, and recommended, design uses brass heat-set inserts in the case wherever parts need to be connected. This is mechanically superior, but requires you to have the inserts.

The alternative is to use bt2.5 self-tapping screws. You probably don’t want to use these if you’re anticipating disassembling your logger 100 times, but they don’t need you to buy heat-set inserts. If you choose this option, then pick the parts with the bt2_5 suffix.

The fasteners needed are listed in the Bill of Materials at the end of this section.

You will need the following printed parts:

• A base (the lower half of the case). Base.stl or Base bt2_5.stl.

• A lid (the upper half of the case). lid.stl or Lid bt2_5.stl.

• A top end piece (the end of the box that faces forward). This piece mounts two M8 connectors.Top end.stl.

• A bottom end piece (the end of the box that faces backward). This piece mounts two M8 connectors and the USB-C connector. Bottom end.stl.

• A nav plate to retain the navigation button assembly. Nav plate.stl or Nav plate bt2_5.stl.

• A power button plate to retain the power button assembly. Power button plate.stl or Power button plate bt2_5.stl

• An OLED spacer to keep the OLED display in the correct position. OLED spacer.stl.

• 6 pins that actuate the buttons on the PCB. Pin.stl

• A plug to go in the USB connection hole. plug.stl. If you don’t wish to use this, tape also works. It must be printed in TPU.

• Caps to go over any unused connectors. These are optional but recommended. They must be printed in TPU.

• A downtube mount (assuming you will mount your logger on your bike’s downtube). It should be printed in TPU but other materials also work.

• A small piece of acrylic or other clear plastic (22mm x 33mm) to go over the screen of your logger. I cut up old goggle lenses to make these but you can also buy 1 mm acrylic sheet on AliExpress

Notes on 3d printing the parts:

Recommended material

Except for the parts noted above that have to be, or should be, printed in TPU, almost any material will suffice. Some however are better than others:

• Carbon-reinforced nylon is the gold standard for this application in my opinion: it is strong, tough and temperature-resistant. I use BambuLab PAHT-CF for most case parts.

• ABS, ASA, PETG and PCTG are all good choices, with or without fiber reinforcing. Even when printing in carbon-reinforced nylon, I use unreinforced ABS for the button assembly parts (pins and plates) because a smooth finish is desirable for those parts.

• PLA works, and carbon-reinforced PLA looks amazing with colored logos printed into it. But I’d consider it a third-tier choice as it doesn’t have much temperature resistance or impact strength.

Bottom line: use the best thing you have, and don’t stress too much about it.

Print orientation and settings

for the case top and bottom, flat on their largest faces, with supports enabled. The print lid requires support for the cutouts in the front face, and for the screw holes. The nav and power plates should be printed in the opposite orientation to the pictures above, with supports enabled. The bottom end piece should be printed on the large flat face with supports enabled. Everything else prints well without supports.

Tree-style supports work well. If you are a more advanced 3D printer user and have access to a machine capable of printing multiple materials, the cutout areas benefit from using an interface layer of dissimilar material (PLA for PETG and vice versa), along with the following support settings:

• Top z distance: 0
• Top interface layers: 2
• Top interface spacing: 0
• Interface pattern: rectilinearOption

Printing cases with inlaid logo: If you have access to a multi-color 3D printer and your slicer software supports it, the easiest way to do so is to import the parts as STEP files directly into your slicer. Once the files are imported, assign the logo inlays with the colors of your choice. The official BODAQS colors are teal for the spring and either white or black for the bar, depending on the background.

BambuLab-format project files are also available in the 3mf directory. a8_all_parts_one_material.3mf has all the parts on a single plate. Each project file has two build plates - one for the base variant that uses brass inserts, and another for the one that uses self-tapping screws.

a8_all_parts_three_colors.3mf is actually set up to use four filments - three colors plus an interface material. It has the same items as the single-color project file but has alternate filament colors assigned to the logo inlays, interface material applied to support-interface surfaces, and the revised support settings described above.

Interface materials

Bambulab and other vendors sell dedicated support-interface materials, but all you really need is two materials that don’t stick well to each other. If you are printing in PLA, you can use PETG as am interface material, and vice versa. If you are printing in nylon, ASA makes a great interface material.

Sensors

The best starting set of sensors is two linear potentiometers (pots). These sensors change their resistance according to how far they are compressed or extended, which makes them useful for measuring suspension movement. Linear pots are available from a range of suppliers including major international electronics distributors, specialist suppliers of instrumentation, motorsport suppliers and manufacturers.

The most economical way to buy linear pots is on AliExpress. There are numerous options, but I personally use these items.

When buying your linear pots, pay attention to:

• Travel: Your pots must have more travel than what you are measuring. If in doubt go a size up, but no more than needed as longer pots can be harder to mount.
• Physical dimensions: Especially diameter. Around 12mm is ideal. Larger diameter pots get harder to mount.
• Mountings: Ideally the pot has spherical bearings (rose joints) at both ends
• Resistance: You want pots with 2-10 k-ohm full-range resistance.

Tools

The following tools are Required or Recommended

Soldering iron

Required You will be soldering pin headers and connectors into the PCB and sensors to plug assemblies, so you will need a soldering iron suitable for electronics use and some solder around 0.8mm diameter.

Optional

The premium soldering iron option is a TS101 or Pinecil USB smart soldering iron. These feature a high power output, rapid heatup, and can be run with a lightweight cable, which makes them excellent for fine work. However, budget options can do the job just fine.

Side cutters

Required You should get a small flush-cut set intended for electronics rather than a larger set intended for more general electrical work.

2.5mm allen key

Required For fitting the case together. If you don’t have a decent set of allen keys, you can pick a set up from almost any hardware store

Wire strippers

Recommended You can strip wire with side cutters if you are careful, or your teeth if you are a maniac, but these make it much easier. You will need to strip wire to wire sensors to plug assemblies.

Multi-meter

Recommended For polarity & continuity testing and fault finding. Even a basic model is sufficient for the needs of this project. Not needed if everything goes perfectly but indispensible if it doesn’t.

Miniature hot air gun

Recommended For heating shrink-sleeve. A match, cigarette lighter, or glossy print of the author (price on request) can be used instead if necessary.

Bill of Materials

Qty	Item	Link	Note
1	BODAQS A8 printed circuit board	JLCPCB	Direct from fabricator
		BODAQS.net	Buy from bodaqs.net
1	0.96” OLED display HS96L03W2C03	AliExpress	Multiple vendors — search “HS96L03W2C03”
1	Nintendo 2DS replacement button pad	AliExpress	Multiple vendors — search “button pad 2DS”
1	Li-Ion Polymer battery pack 3.7V, JST-PH 2-pin connector	SparkFun	Recommended if purchasing from the US
		Kiwi Electronics	Recommended if purchasing from the EU
		Altronics	Recommended if purchasing from Australia
		AliExpress	Check dimensions — model 524261 from this vendor
1	Header socket, 8.5mm high, 2.54mm pitch, single row, 4+ sockets	SparkFun	Recommended if purchasing from the US
		Kiwi Electronics	Recommended if purchasing from the EU
		Altronics	Recommended if purchasing from Australia
		AliExpress	Multiple vendors — search “Socket header 8.5mm”
4	Amphenol M8 circular connector M8AS-06PMMR-SF8001	DigiKey
		AliExpress	Purchase plug assemblies from the same vendor — read the guide
4	M8 plug assemblies Amphenol 8A-06AFFM-SL7A01	DigiKey	DigiKey
5 max	M6 plastic circular connectors — 3 pin	AliExpress	Multiple vendors — search “M6 connector”. Read the guide to decide how many you need.
3 max	M6 plastic circular connectors — 4 pin	AliExpress	Multiple vendors — search “M6 connector”. Read the guide to decide how many you need.
1	22mm × 33mm × 1mm acrylic panel	AliExpress	You can make this from a clear lens from a set of goggles.
1	CR1220 button cell battery		For the real-time clock. Available almost anywhere.
1	16GB (or larger) MicroSD card		Available almost anywhere.
	2.5mm shrink sleeve		Available from most hardware shops and electronics suppliers.
	10mm shrink sleeve(if making y connections)		Available from most hardware shops and electronics suppliers.
	Neutral-cure caulking silicone		Available from most hardware shops.

Fasteners (option 1 - using brass inserts)

Qty	Item	Link	Note
14	M3 × 5 × 4.2 heat-set brass inserts	AliExpress	Multiple vendors — search “M3 brass insert”
4	M3 × 12 stainless-steel socket-head cap screws	AliExpress	Multiple vendors — search “M3 stainless steel hex”
4	M3 × 8 stainless-steel socket-head cap screws	AliExpress	Multiple vendors — search “M3 stainless steel hex”
6	M3 × 6 stainless-steel socket-head cap screws	AliExpress	Multiple vendors — search “M3 stainless steel hex”
4	M2 × 5 stainless-steel button-head cap screws	AliExpress	Multiple vendors — search “M2 stainless steel buttonhead”

Fasteners (option 2 - using self tapping screws)

Qty	Item	Link	Note
8	BT2.5 × 8 self-tapping screws for plastic	Bambu Lab	Also available on AliExpress
10	BT2.5 × 5 self-tapping screws for plastic	Bambu Lab	Also available on AliExpress

3D-printed parts

Qty	Part
1	Logger case — base
1	Logger case — lid
1	Logger case — top end
1	Logger case — bottom end
1	Logger case — nav plate
1	Logger case — power-button plate
1	Logger case — OLED spacer
6	Logger case — pin
1	Plug
4	Caps
1	Downtube mount