OBO Bettermann A8 Junction Box

This is a well tried and tested design and fits all versions of PippyG and AudioMoth. Widely available from many stores, including Amazon
Size in mm = 75w x 75d x 37h

“Type F with Ears”

A stronger, smaller and more sealed box. It only fits PippyG 4.x and AudioMoth v1.1+. Can be harder to find online, as often out of stock on AliExpress or eBay (eps.. black).
Search for: “Case 83x58x33”
Size in mm = 83w x 58d x 33h

For making the case covering for the microphone hole. We recommend two layers of 316 Stainless Steel mesh, coated to make them Hydrophobic:

• Fine 400 gauge, 400 wires per inch, 35 micron holes – For the covering nearest the mic hole
• Coarser 80 gauge, 80 wires per inch, ~175 micron holes – As a cover to deflect high energy raindrops from the fine mesh

This is optional, but if you want to hide your PippyG or AudioMoth away from the publics gaze it can be very useful. You are looking for “Self-adhesive Waterproof Cloth Camo Tape“, it comes in several designs usually in a 50mm wide roll, 5 m or 10m long.

You do NOT want the type of elastic camo wrap that is sold for covering outdoor equipment like rifles. This is stretchy and self conforming, only sticking to itself. Hence it is only useful for “wrapping” things.

To ensure you align the microphone of the Pippyg accurately with the vent hole in the case, it is necessary to sacrifice one of your PippyG boards. Drill out the mic hole with a 3mm high speed drill. To accurately enlarge the mic hole from 0.7mm, we first like to drill with a 1.5mm drill, then enlarge with a 3mm drill.
This then becomes your Mic hole template for all future case builds.

Experience has taught us that is well worth writing on the Mic Hole temple, both which version of the PippyG it is for, and also to mark clearly on the back which hole needs to be drilled for the microphone. Daft as it sounds, with the several mounting holes in the PippyG v4.04 its very easy to drill the wrong hole. (yes, we have done it…)

It is worth mentioning that Phil and Apodemus have moved the mic hole around…

• PippyG v 3.71 and earlier, and the Apodemus Pippyg1 are the same.
• PippyG v4.0 and later, moved the Mic about 1.3 m towards the top of the board.
• The Apodemus Pippyg2 appears to have moved the mic more central.
• The AudioMoth mics have not moved, but are located in a different corner to all above.

The result of this is that, for each of the types above will need to make a different case. 😒

When your mesh arrives the first thing to do is to make it hydrophobic (water repelling) by applying a soaking of a waterproof product such as NicWax or similar.

Flood both gauges of mesh with the waterproofer, then shake or blot off the excess, and allow it to dry overnight before using.

This push fit case is “universal”, it is slightly bigger so can be used with all PippyG (including Apodemus) and all AudioMoths. However as the Mic hole position varies a lot between these devices, once made it is specific to a type of device.

The process consists of two parts:

1. Fitting the device into the lid of the case, and make the vent for the mic.
2. Padding the bottom of the case to ensure the device stays in close contact with the lid

Start with the lid:

1. Shave lip – The top of the lid of the A8 has raised writing, symbols and a edge lip on it. To ensure the mic vent has a good seal it is a good idea to use a scalpel to carefully shave off and remove the raised lip, where the mic vent will go. This is the bottom left corner of the lid under the VDE triangle symbol.

2. Cut foam strips to locate PCB – Using a cutting mat, scalpel and metal ruler, cut the self adhesive double sided foam into 8mm wide strips. As the backing of the foam is slippery and moves easily, for accurate cuts we find it useful to temporarily tape the foam to the back of the ruler using small bits of gaffer tape, and to use extra foam to support the ruler and keep it level. An alternate worth trying is VERY sharp scissors (like dressmaking scissors).

3. Place foam in lid to locate PCB – Turn the lid upside down, and place the Mic template PCB in the middle of the lid, with the top of the PCB up against the bottom of the lid. Take a 8mm foam strip and cut to the length of one side. We find this easiest by placing and using the scalpel to mark it. Cut the corners of the foam to fit the case, and test fit. If happy, peal the backing from the bottom of the foam and stick into place. Do NOT remove the top backing of the foam.
Repeat for the other two sides, and when done ensure the PCB is snugly, but not tightly held.

4. Drill Mic Hole – Using a 3mm HSS drill straight down thought the lid, through the correct hole on the mic hole template.
After drilling using a scalpel tidy up the edges of the hole. A slight (1mm) countersinking on the outside of the hole is a good idea.

5. Cut the 80 s/s mesh – The 80 gauge stainless steel mesh is used to absorb the energy of high velocity water drops. Using scissors, cut a 25mm wide strip of the 80 mesh.
From this strip cut a pentagon (house shape), a 25 x 25mm square with a 7mm high Isosceles triangle on top (see photo). The triangle shows which way up, and helps deflect water running down the face of the case.
This 80 gauge pentagon (house shape) becomes your template for the next stage.

6. Cut mounts – Use the 80 gauge mesh as a template, and using scissors cut two similarly shaped sections of the 25mm double sided mounting tape.
It is FAR easier to do this if you first stick some of the own tapes spare backing to the end of the roll first. If you have made a case before you will already have these backings. But if its your first case it is well worth sacrificing the first 35mm of the tape to get to reusable backings.
Then cut a 6mm wide by 12mm high slot out of the bottom (not triangle) sides of these mounts. This is to allow any water that does get though the mesh to drain out downwards.

7. Place 400 mesh s/s mesh – Remove (and keep) the backing from one of the mounts, then place it over the mic hole as shown in the photo press down firmly. Remove the top layer of the mounting tape backing (this is quite tricky!), again keeping the backing.
Cut a 12mm square out of the 400 gauge stainless steel mesh and place it onto the mount so it is central over the microphone hole. Press down carefully, avoiding the adhesive.

8. Place 2nd mount – Remove the backing from the underside of the second mount and place it exactly over the first mount. Take care, as you one get one go at this.
Note: The slot on the second mount in the photo is a little deep. Ideally with a shorter slot, more of the second mount would overlap the 400 s/s mesh for a better seal.

9. Place and glue top mesh – Remove the backing from the top of the second mount, and press the 80 gauge s/s mesh firmly into place. As the mesh is treated, you will find it does not stick that well. Hence we run a bead of superglue around the three top and side edges of the 80 mesh, and allow this to dry thoroughly (make take several hours).

10. Cut out 8mm foam for base – Using the upturned base of the case push it down into the 8mm thick foam sheet. This will make an indentation that you can cut around with scissors.

11. Fit foam into base of case – Take the cut piece of 8MM foam and push it upside down into the base of the case, press hard.
Using a scalpel cut out the marked areas, to allow for the indentations in the base. Then push fit the foam into the base, it should be a tight fit so no need for glue.

This screw together case is stronger and smaller, it can only be used with DIY PippyG version 4.0.x and later (narrower board), or AudioMoth v1.1 or later (recessed switch).

As the A8 before, the process consists of two parts:

1. Fitting the device into the lid of the case, and make the vent for the mic.
2. Padding the bottom of the case and enlarging the mounting holes.

Start with the lid:

1. Waterproof seal – The cases waterproof seal comes loose inside the case, it is white silicone rubber and round in section. Push it into the groove on the lid.

1. (optional) Cut 10mm foam strips to locate PCB – If using 10mm high foam you can go straight onto step 2. Otherwise using a cutting mat, scalpel and metal ruler, cut the self adhesive double sided foam into 10mm wide strips. An alternate worth trying is VERY sharp scissors (like dressmaking scissors).

2A. Cut first 10mm foam in lid to position PCB – Turn the lid upside down. Take a 10mm foam strip press down hard across the width of the case to mark it out.
Use the indents to cut to the required shape. length of one short side between the screw holes. We find this easiest by placing and using the scalpel to mark it.

3A. Place 10mm foam in lid to position PCB. Remove one side of backing tape of the first cut strip and stick into place. Do NOT remove the top backing.
Insert the Mic hole Template, then repeat the above process to cut the second foam strip (approx. 7mm wide) at the other end. Cut short so it does not snag the position of the microSD card.
Remove the lower backing and stick into place, do NOT remove the top backing.

2B. Place 10mm foam in lid to position PCB – Turn the lid upside down. Take a 10mm foam strip and cut to the length of one short side between the screw holes. We find this easiest by placing and using the scalpel to mark it. Remove one side of backing tape and stick into place. Do NOT remove the top backing of the foam strip 1 yet.
Cut a second strip to go on top of the first, bevelling the ends. Test fit, then remove the one side of backing tape of this, and the top of first strip, and fix the second strip over the first.
Repeat the process until you have built up a 9 to 10mm thick pad. This takes 3 strips of 3mm thick, or 5 strips of 1mm thick foam.
Do NOT remove the top backing of last 10mm foam strip.

3B. Adding “squashy” foam – From squashy foam (or sponge) cut a strip 10mm x 8mm.
Cut the squashy foam strip so it fits the end of the lid opposite the foam pads. Test fit. If OK, apply 10mm wide double sided tape to hold it in place.
Test fit the PippyG board by push fitting it into the squashy foam first, then lowering the other side. Move onto step 4.

4. Drill Mic Hole – Using a 3mm HSS drill straight down thought the lid, through the correct hole on the mic hole template.
After drilling using a scalpel tidy up the edges of the hole. A slight (1mm) countersinking on the outside of the hole is a good idea.

5. Cut the 80 s/s mesh – The 80 gauge stainless steel mesh is used to absorb the energy of high velocity water drops. Using scissors, cut a 25mm wide strip of the 80 mesh.
From this strip cut a pentagon (house shape), a 25 x 25mm square with a 7mm high Isosceles triangle on top (see photo). The triangle shows which way up, and helps deflect water running down the face of the case.
This 80 gauge pentagon (house shape) becomes your template for the next stage.

6. Cut mounts – Use the 80 gauge mesh as a template, use scissors to cut two similarly shaped sections of the 25mm double sided mounting tape.
It is FAR easier to do this if you first stick some of the own tapes spare backing to the end of the roll first. If you have made a case before you will already have these backings. But if its your first case it is well worth sacrificing the first 35mm of the tape to get to reusable backings.
Then leaving both backings on, place the mount in position on the case, just missing the screw hole.
Using a marker pen mark the centre of the mic hole on the tape backing. Due the position of the case screws and PippyG this will be off centre.
Then cut a 6mm wide slot out of the bottom (not triangle) sides of the mount, to just above the mic hole marking. This is to allow any water that does get though the mesh to drain out downwards.
Repeat the process for the other tape mount.

7. Place 400 mesh s/s mesh – Remove (and keep) the backing from one of the mounts, then place it over the mic hole as shown in the photo. Press down firmly. Remove the top layer of the mounting tape backing (this is quite tricky!), again keeping the backing.
Cut a 12mm square out of the 400 gauge stainless steel mesh and place it onto the mount so it is central over the microphone hole. Press down carefully, avoiding the adhesive.

8. Place 2nd mount – Remove the backing from the underside of the second mount and place it exactly over the first mount. Take care, as you one get one go at this.

9. Place and glue top mesh – Remove the backing from the top of the second mount, and press the 80 gauge s/s mesh firmly into place. As the mesh is treated, you will find it does not stick that well. Hence we run a bead of superglue around the three top and side edges of the 80 mesh, and allow this to dry thoroughly (make take several hours).

10. Cut out 8mm foam for base – Using the upturned base of the case push it down into the 8mm thick foam sheet. This will make an indentation that you can cut around with scissors.

11. Fit foam into base of case – Take the cut piece of 8MM foam and push it upside down into the base of the case, press hard.
Using a scalpel cut out the marked areas, to allow for the six indentations in the base. Then push fit the foam into the base, it should be a tight fit so no need for glue.

12 – Enlarge case mounting holes – Using a 6mm high speed drill, enlarge the mounting holes in the lugs of the case. This will allow for a wider range of things to be used to locate the case in use, such as bungee cords or thicker zip ties.