Wireless mouse to eye mask modification

20 05 2017

Followers and readers of my blog may well remember my previous optical mouse hack for REM eye movement detection and lucid dreaming back in August 2014. That project known as DreamCaptcha relied on a direct USB connection to a nearby computer. Hopefully after having a bit more time I can now move on from that limitation by experimenting with a wireless mouse set-up instead.

modified wireless mouse dream mask

Optical wireless mouse prototype

 

The layout and construction is very similar to the earlier USB mouse hack. In fact I kept the milk carton shell and the elastic as before. Even the white tack to temporarily hold the base in is taken from that project era. However there were obvious benefits and certain obstacles to overcome during the whole modification process, most of which included the weight and power considerations, amongst others.

 

Background

The Belkin Wireless Travel Mouse (Model No. F5L 017 ne USB-RED) runs on 2 AAA-sized batteries. The wireless operating frequency (identified on the crystal) is 27.042 MHz. A USB dongle is provided which acts as the receiver. No device drivers are needed as the computer installs everything on detection.

Both devices must be ‘paired’ initially and be in range to work satisfactorily. The range is about a couple or so feet or more, although this can vary due to the batteries or if there are any obstructions nearby.

The Belkin 27 MHz wireless travel mouse

The Belkin 27 MHz wireless travel mouse

 

Most people are familiar with Wi-Fi connection to their computer which is a similar concept. Likewise you can get Bluetooth and 2.4 GHz wireless mice. The major downside, apart from the expense is that all these devices use microwaves to transmit their data. This is the reason I chose a 27 MHz mouse for this project to lessen the risks to the eyes from RF energy. In fact 27 MHz is best known as the CB ‘Citizens Band’ where radio operators known as ‘breakers’ can communicate locally or worldwide (DX). The output power from a typical basic mobile CB AM/FM radio or ‘rig’ is about 4 Watts minimum. Single-sideband (SSB) is usually a lot more especially with a base station, but the mode is far more efficient.

A ¼ wave whip aerial for CB is roughly 8 ½ ft. Double that size for a ½ wave base antenna. The mouse shown here will output a fraction of this power without any added extra wire or external antenna.

I would strongly advise people not to use or experiment with the 2.4 GHz types, unless you can screen it really well. These are usually recognisable from the small dongle in most (but not all) cases. The actual frequency specification should be listed at the point of sale.

Wireless mouse underside

Underside view showing the optics

 

Deconstruction

As in my previous mouse project I would need to remove the case, modify the base assembly and the PCB circuit board. The visible red LED used for the optics would be replaced with an infrared LED from an old remote control, as before. Make sure you test and make a note of the polarity before fitting it.

I would then need to cram the whole thing into my cup. This cup is a cut out top section of a 1 Litre plastic milk carton from my previous project example. I have tried to match the contours around my right eye and the side of my face using a trial and error method. For that reason I cannot give any exact dimensions as it is fairly bespoke.

Wireless mouse after disassembly

Mouse after disassembly

 

Often the screws are ‘hidden’ under the stick on feet or under labels. The 27 MHz crystal is below centre on the PCB board. The optical transmitting LED and the receiving chip are shown towards the top centre of the board itself, with the transparent lens/prism assembly in between. Note the black opaque cover has been removed for this photograph. It is important to note that you should avoid getting any dust or fingerprints on or in these components, where possible. The lens and prism assembly will need to be cleaned lightly with a lint-free, non-abrasive cloth afterwards before fitting the protective cover back.

Wireless mouse PCB board (top view)

Mouse PCB board (top view)

 

Most mice will have a similar layout of components regardless of the make. The standard encoder scroll wheel and the associated switch, along with the left and right switches will not be needed in this instance.

Wireless mouse PCB board (underside)

Mouse PCB board (underside)

 

When tailoring your mouse to fit it is important to make a note of the track layout both sides before cutting any part of the PCB board away. This is because there are tiny through connections that link each side.  You can normally do away with the scroll wheel and the switches as their path to the main IC is not reliant on anything else. The switches are ‘normally open’ or off. Any ‘common’ connection that is cut may have to have a wire link soldered in place afterwards however, dependent on your actual layout and mouse model.

Modified mouse board and base assembly

Modified board and base assembly

 

It is advisable to check that the mouse still works somewhat after each modification, so that you can step back and retrace what you previously done. This is where your initial photographs or diagrams come in!

Ironically I cut right across one of the common tracks on the top perimeter of the board and one or two underneath, plus a cap had to be moved. In my case the wireless optical tracking in my mouse still worked. No extra links needed!

Likewise the base plastic was cut and sanded to fit. The plastic lens and prism was then cleaned, checked and fitted after the original LED had been replaced with an IR counterpart. The PCB was tacked on to the base using hot-glue along with the black lens cover.

Mask cup and modified mouse PCB comparison (without base)

Modified mouse PCB comparison (without base)

 

I ordered a holder for a standard 3 volt CR 2032 button cell battery. These are the ones you find inside computers as part of the CMOS back-up circuit. I tweaked the old AAA battery prongs so the holder could be soldered on easy. These two prongs however are a bit springy and the battery would be needed to be changed once it had expired so easy access would be necessary rather than taking the mouse apart.

Top view of modified mouse PCB board showing battery

Top view of modified PCB board

 

A couple of plastic struts were then hot glued into place as the holder itself sits over an inch proud off the board. This made the battery housing rigid and the battery could be changed via the removal of the blue screw off cap. I did not know however the actual battery consumption of a CR 2032 in this scenario. I just knew it fitted well and it was much lighter when compared with the bulkier AAA types.

Final wireless mouse assembly fitted in cup

Final wireless mouse assembly fitted in cup

 

Finally I basically fitted the modified mouse inside the cup. White tack was added near the corners, etc. just in case I have to modify the base or move the mouse afterwards during the initial testing periods.

Underside view of mouse mask

Underside view of mouse mask

 

Roughly 19” of ½” width white elastic was threaded through each side of the cup after two small holes were made through the plastic with a soldering iron. A single knot on the inside terminates each end of the elastic in order to make the fitted band which fits around your head. This band arrangement hopefully keeps the mouse cup in place during a test phase or a wake back to bed (WBTB) session.

 

Initial considerations and testing

The elastic/cup/mouse arrangement is not that comfortable. I am relying on the elastic tension being less over time as it seems quite tight at first. Also the base of the mouse feels like it is either resting or pressing slightly on the closed eyelid. This may improve with use due to the overall tension. I will need to monitor or address this later on. At the moment I am a bit reluctant to shave or sand more plastic off the base. I could remove the base entirely but I would still need a protective layer between the PCB and my eye/eyelid. If the lens assembly is too far back or misaligned then the minute tracking needed for REM eye or eyelid movement will not be detected properly, if at all.

There may be also a ventilation issue to consider. I could simply add a few strategic holes in the cup probably to get around this if air circulation becomes a major problem. Likewise this could include problems with lens cleaning due to sweat and moisture build up.

However I do not expect too much trouble as this device is intended to be used for wake back to bed periods only, and not overnight. The latter would be too uncomfortable plus this cup is for one side only.

Wireless mouse mask (side view)

Mouse mask (side view)

 

A basic finger-motion test confirms that the optical tracking still works like a normal mouse. However I do have to have the wireless mouse cup within one to two feet of the main dongle. This is just about acceptable, but ideally I would like a reliable range at least double that.

For the meanwhile I intend to test by having the dongle connected to the laptop via a USB extension lead which is 1 metre in length. The dongle can now be placed near me at the top of the bed for the best signal.

Computer set up with mask and dongle

 

When triggered, the laptop would play an audio track whilst running the Lucid Scribe software from Michael at Lucidcode, so the laptop would have to be quite near me anyhow. The use of headphones defeats the whole idea of being wireless, unless you have access to Bluetooth LE in-ear headphones which would probably be more expensive.

With this test I still had an earlier version of Lucid Scribe (v1.4.2). I decided to use that still as I was running the software on an old laptop, plus it was the same version I had used during my other USB mouse example. I could therefore check for comparisons between the two if I so wished later on, rather than upgrade it since.

Close-up of mouse underside showing infrared LED operation

Close-up of mouse underside showing infrared LED operation

 

Live testing

Last night I set up the laptop and dongle in close proximity to my bed. I ran one or two preliminary tests with the mouse cup and software whilst awake in order to try and familiarise myself again after my long break.

Early this morning (after 4 am) I took a brief wake back to bed. However I decided to try out my mouse for real. I therefore included the setting up routine and initial software tests as part of my extended wake back to bed.

Whilst trying to lie on my left hand side in bed, in preparation to sleep I found there were several problems encountered. The first one I came across was with the range and communication between the dongle and the mouse. At first I thought it was a battery problem. The red LED on the dongle kept on flashing like it had timed out. I found I had to switch the mouse off and on a couple or so times as well as reset the dongle and mouse. I also had to reseat the cup over my right eye several times, trying to get the whole housing comfortable and making sure the optics were tracking reliably.

It did not help that the laptop decided to go into ‘sleep’ mode even though I thought I had set the power options up via the device manager last night. Ironically the computer dropped off to sleep before me!

Once these issues were sorted I found that nearly an hour or so had passed. I also felt quite uncomfortable in bed still. Even so I did start to feel sleepy where I would notice brief fleeting imagery. The mouse/dongle combination seemed to be working to some extent too as I rested. For example even with my eyes shut I would notice the occasional blinking of the red dongle LED when the mouse was picking up the odd non-REM eye movement or two. I knew the mouse was possibly sensitive enough; otherwise there would be no real time communication.

My sleep was seemingly lighter than normal, coupled with my slightly awkward sleeping position, the laptop fan noise and the ambient light in the room. Even so I did manage to track at least one dream during the actual main test this morning. Considering all the unfamiliarity, this was an achievement in itself, even though the triggered track roused me from my sleep.

Recorded data from mask at 6.15 am on the morning of May 19th 2017

Recorded mask data from 6.15 am on the morning of May 19th 2017

 

I cannot really account for this data as I do not remember. The x-y spikes (coloured blue and mustard yellow respectively) indicate that I was sleeping, rather than resting as such. Wakefulness for example seems to produce more spikes from what I have noticed during my other tests.

I should point out on Lucid Scribe, the vertical axis shows the amplitude or steps, whilst the horizontal axis is the time period in seconds. In this case a whole minute is shown. These individual log files are shown on the left hand side.

Recorded mask data from 6.19 am on the morning of May 19th 2017

Recorded mask data from 6.19 am on the morning of May 19th 2017

 

From my written notes I wrote the time down as 6.19 am after waking which correlates with this data. This was the triggered song that roused me from my sleep from what I remember, even though the previous screenshot data is only 4 minutes beforehand.

This is why I think it helps to have your clock and computer synchronised to the same time and to write brief relevant keynotes down in real time, rather than rely on memory alone later on. You can be more certain of the results when you look back on everything.

Note that the downward stairway (orange/brown) trace is fairly gentle. I woke up but I tried to stay as relaxed and still as possible in order not to mix up any data or get it confused. This would help me analyse it afterwards.

It could be that the 6.15 am even was the start of the dream? The second screenshot was the end of the brief dream which was non-lucid by the way.

 

The actual dream:

I notice there is a neat pile of grey paper (slate grey coloured, approx. 12” x 12” square) sitting on the left of the table. I think I go to touch or choose one from the top. I said that D. (the art technician) had nicked all the expensive paper.

 

After about 6.22 am, after writing down my brief notes I finished testing with the mask cup and shut the computer down before retiring to bed again. I wanted to get a full rest rather than do too much testing.

 

Disclaimer

This project is presented as a prototype for possible post-WBTB use. The article is presented here as a guide only.

Under NO circumstances should a mouse that uses a laser or laser-type diode be used, or substituted with one as serious eye damage will result, even blindness. Avoid microwave mice.

The majority of mouse circuits tend to use flickering or strobing LED light optics in their design. Therefore this project should be avoided by anybody who is photo-epileptic or photosensitive. Seek medical advice if you are unsure, before undertaking such a project.

The author, Lucid Dream Art does not assume responsibility or any liability whatsoever for personal injury, including damage to computer equipment whilst making, testing, or using the project itself. The experimenter does so at his or her own risk.

© 2017 Lucid Dream Art. All rights reserved.

 

(Lucid Scribe data appears courtesy of Michael Paul Coder at Lucidcode.com)

 

Advertisements

Actions

Information

One response

22 05 2017
Michael Paul Coder

Reblogged this on lucidcode.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s




%d bloggers like this: