A new cave surveying device on the block...

[Hall2501]

The DiscoX1 - A new cave survey device

I've had a big push recently to finish designing a new cave survey device, the Disco-X1 in time for Hidden Earth. Tested it in a forest this morning, and it seems to actually work. I'll be giving a talk about it at HE/happy to talk about it to anyone over the weekend. Here are some highlights:

Componets
Most of the components are the same as the SAP6 (much of the firmware is identical, thanks to Phil's open source code), but I've added a few extra things to give it some umph. The Disco-X1 includes a special chip that monitors battery % with super high accuracy, a dedicated on/off chip that toggles power, a 1.12-inch OLED screen, RGB LED lighting, a 1200mAh battery (10 hours of battery life), a powerful ATSAMD51 series microcontroller with an ARM Cortex-M4 processor, with lots of memory and fast processing speeds, and an industrial ISM330DHCXTR accelerometer. I've designed the device to be fairly modular, the idea being that if any single component fails, then you only have to replace the component rather than the entire device. Below is a photo of the device disassembled.

User interface
The interface is simple and has 4 buttons:

• Take Reading Button - Takes a compass, clinometer, and distance measurements.
• Disco Button - Activates RGB disco mode, turning the device into the ideal rave companion.
• Calibration Button - Enters calibration mode, with on-screen instructions guiding you step-by-step through the process.
• Power Button - Turns the device on or off.

The device settings and preferences can be set by plugging the device into a PC and changing the parameters in a settings file, e.g. error tolerance, display modes, power off due to inactivity timeout etc. The code is also completely open to the user to change, if they want to make the device behave differently or add extra features. I've had a few people request that I add a snake as an in survey device game.

Enclosure
The enclosure is 3D printed and made from PETG. This plastic apparently does well in humid environments and has good layer adhesion, preventing water ingress through tiny gaps in the layers. The top cover is made from machined polycarbonate with a 3D printed bezel and waterproof membrane buttons. The laser is protected by a scratch-resistant quartz glass cover, the display by Gorilla Glass and there is a waterproof USB-C port at the back. I'll be using UV-cure resin to waterproof any gaps.

Soft Launch
I plan to make a small batch of devices for some initial field trials over the next few months. After gathering user feedback and finding any potential faults, I'll revise the design/software and release the DiscoX2.

Price
This really depends on how well the pilot release goes. If it proves to be robust and reliable, I'll probably commit to a large batch run to try and recoup some of the R&D, equipment and manufacturing costs. But it's currently looking like it'll be around £450 per device in time for the 2026 expedition season.

 

[furbrain]

That looks awesome! I'd love to have a play with it this weekend.

 

[Hall2501]

Quick update, I've been doing more testing and it appears the DiscoX is a pretty capable survey device. I'm planning to release 3 devices for field testing in the next few weeks, then follow up with a small batch run. If anyone's interested in buying one, feel free to get in touch. I've set the price at £470, slightly higher than my initial estimate, as I'm in the process of getting a few custom-made membrane buttons that should be significantly more reliable than the generic ones I bought off AliExpress. + a few extra bits inside the device to secure all the components.

I've made a website too, I'll be updating it as the project develops.

 

[mountainpenguin]

This does look amazing. I gave some thought to building something similar many years ago so best of luck.
One quick comment 3d prints regardless of material tend not to be waterproof (micro holes between the layer lines) though this can be fixed by epoxying the final version.

Extreme Waterproof 3D Prints

Since the crew at [CPSdrone] likes to build underwater drones — submarines, in other words — they need to 3D print waterproof hulls. At first, they thought there were several reasons fo…

hackaday.com

The design looks great though maybe plastic CNC for small enough volumes (PCBway and others will give you a quick quote)

 

[Hall2501]

I think the modern printers, are quite good at making water proof parts if you go for thin layer lines, thick walls and a melty plastic like PETG. I'm yet to test at higher pressures but from what I've seen from testing it so far it's pretty waterproof. I was thinking about conformal coating the inner walls as a last line of defence but I'll see if I can send a case out on a diving trip and see how it does.

 

[oliverdattilo]

What justifies this vs the SAP6? The internals are nearly identical, so there must be something besides the admittedly awesome "rave mode"!

 

[Hall2501]

They're pretty similar, mine has a different case design (quartz glass laser cover) slightly bigger screen, bigger battery, potted USB C connector and more buttons. The main difference in the internals is that mine uses 2 microprocessor units to give me a bit more breathing room on the programming side. All of the core firmware modules are the same as the SAP6 (sensor drivers, calibration algorithm) but I'm writing my own UI. It also uses the same laser module as the SAP6 and I've been having similar issues with range underground, but I've found for longer legs pointing the laser at a retroreflective surface eliminates the range issue so I might just have to sell them with a foldable road sign or something...

 

[Tritim230]

They're pretty similar, mine has a different case design (quartz glass laser cover) slightly bigger screen, bigger battery, potted USB C connector and more buttons. The main difference in the internals is that mine uses 2 microprocessor units to give me a bit more breathing room on the programming side. All of the core firmware modules are the same as the SAP6 (sensor drivers, calibration algorithm) but I'm writing my own UI. It also uses the same laser module as the SAP6 and I've been having similar issues with range underground, but I've found for longer legs pointing the laser at a retroreflective surface eliminates the range issue so I might just have to sell them with a foldable road sign or something...

On range, unless you use a tripod the limitation is normally the ability of operator to hold it steady.

Also, often one doesn't want the longest shot always as there may be side passages or cave features that may require splays or sections at the next station.

So, IMHO, range is not an issue, certainly not for me in the UK. My expedition days are long gone.

 

[MarkS]

I think a big advantage of decent range is when it comes to splays in high passages. It's not typically a problem where I've done most of my surveying in the UK though...

Although it does remind me of surveying a river passage in China when over the course of a couple of kilometres from sink to resurgence we only had one "up" measurement that didn't give an error, and that distance was 180 m or thereabouts!

Apologies for digressing. It's great to see more innovation and availability of surveying devices.

 

[oliverdattilo]

They're pretty similar, mine has a different case design (quartz glass laser cover) slightly bigger screen, bigger battery, potted USB C connector and more buttons. The main difference in the internals is that mine uses 2 microprocessor units to give me a bit more breathing room on the programming side. All of the core firmware modules are the same as the SAP6 (sensor drivers, calibration algorithm) but I'm writing my own UI. It also uses the same laser module as the SAP6 and I've been having similar issues with range underground, but I've found for longer legs pointing the laser at a retroreflective surface eliminates the range issue so I might just have to sell them with a foldable road sign or something...

What about the range causes issues?

 

[Hall2501]

What about the range causes issues?

For some reason on dark wet rock you struggle to get legs of more than like 10m. If anyone can recommend a better laser module I'd be happy to try it. Good thing about the design is that it's relatively easy to swap out components. Although I've just bought a bunch of lasers already so the first ones will be sold with those.

 

[Hall2501]

The laser module is the exact same one sold with the BRIC so technically it should be able to do upto 100m but it really depends on the conditions

 

[Hall2501]

I think a big advantage of decent range is when it comes to splays in high passages. It's not typically a problem where I've done most of my surveying in the UK though...

Although it does remind me of surveying a river passage in China when over the course of a couple of kilometres from sink to resurgence we only had one "up" measurement that didn't give an error, and that distance was 180 m or thereabouts!

Apologies for digressing. It's great to see more innovation and availability of surveying devices.

Was that with a disto?

 

[MarkS]

Was that with a disto?

A long range disto I think (not a distoX)

 

[Hall2501]

A long range disto I think (not a distoX)

Under normal conditions it has a range is about 30m so I guess for super long legs you could use another device to measure long splays.

I'm looking at

 

[Hall2501]

Ahh turns out I made an error on the PCB by using a 600mA 3.3V regulator for the 500mA laser, apparently that's not enough headroom so I've upgraded to a 1000mA regulator which should give me better results. This explains why the laser worked okay when I had a full battery but not when the battery was low. I've ordered the next batch of PCBs, should arrive in a couple weeks. - I think that should boost the range to something like 40-50m per leg or 100m+ when using retroreflective targets.