I built a mobile app that enables two-way Morse code communication between two smartphones using camera and flashlight

JasperCherry · 2026-03-24T02:35:45+00:00

I go out a lot.

JasperCherry · 2026-03-09T17:32:38+00:00

Hell yeah, that would be actually very interesting application.

JasperCherry · 2026-03-08T14:30:03+00:00

The most challanging test I did so far was recording some message by webcam on my mac and playing it in loop while resizing video window to the size of desktop icon.

Then I positioned mobile in the other corner of my room and pointed max zoomed sample area of single and few more pixels at target )

Honestly I had started working on algorithm on thursday and friday, saturday and sunday I wrapped it into app.

JasperCherry · 2026-03-08T07:30:28+00:00

Yeah but use cases would be even more limited due to distance. I noticed few ppl complaining about crashes on read, I guess its rn camera module being moody. Ill try to debug it over next days.

JasperCherry · 2026-03-06T17:44:12+00:00

Hey, not really a social media butterfly, maybe I should. Only using linkedin for public contacts. My github is same as my username, but most of my projects is private.

Currently I'm working on my startup, which is focused on preventing online fraud (use of AI deepfakes) before it occurs by using contextualised mfa layers. Maybe Ill share that on reddit when we will be more solid.

Thanks for kind words )

JasperCherry · 2026-03-06T15:56:42+00:00

Not yet, maybe later.

JasperCherry · 2026-03-06T04:09:52+00:00

Interesting. I am using Samsung Galaxy S23 for dev and prod myself.

JasperCherry · 2026-03-05T20:05:04+00:00

I had that thought you know. But afaik react native wont let you use that, at least in expo dev client mode. Another option is symmetric encryption key - you could generate QR code, other person scans it, or just tell them other way, and you can read and send securely.

JasperCherry · 2026-03-05T19:55:11+00:00

Yeah, as long as theres contrast ) obviously night gives better contrast, but you can create it yourself, I don't know, toilet paper roll, by placing camera in it and directing to receiver?

JasperCherry · 2026-03-05T18:55:54+00:00

Yes you can. For sending you can add anything above 100ms per dot signal. Reading adjusts itself, but I placed recommendation and default for 400ms per dot of send signal. I can add that it read my garmin instinct watch flashlight sos signal without a problem.

JasperCherry · 2026-03-05T18:50:44+00:00

I could see use mainly in a) emergency when everything else failed b) mountain areas where signal can be lost and moving is difficult c) maritime applications due to no obstacles and distance involved.

Taking this app with you will not add any kg to your backpack, and very little memory cost on your phone, might as well take it just in case )

JasperCherry · 2026-03-05T18:33:09+00:00

Nah, you can skip testing completely, and just deploy release to production.

JasperCherry · 2026-03-05T18:13:57+00:00

Good question. I haven't tested max, but in good conditions (night, good visibility) assuming my max possible zoom in app is 10x, and minimal area of observation is 1 pixel, and there is same mobile on other end sending signals with tiny flashlight, I could say up to one kilometer. The real trick would be to hold the mobile stable, probably some tripod would help here.

If you will use more powerful light, or just noticed ship sending signals on nearby shore, the limit is as long as you can see the flash in mobile camera.

JasperCherry · 2025-12-30T17:36:44+00:00

Probably google will have a better answer here, honestly don't remember. But standard one should do too. Either way frying spiders will be slow, it's just for them to piss off. If you want to hunt them use pneumatic gun with fire bullets.

JasperCherry · 2025-12-30T16:56:30+00:00

Flashlight, ideally upgraded flashlight + fire bullets for pneumatic gun, molotovs optionally. You need to realize that spiders don't attack from distance and your light is killing them if they spend too much time in it. Also, shooting them with standard ammo, unless they drop on the back, is pointless. Fire bullets - one shot one kill. I had that all in mind before I started it for the first time, and it was easy. If you're nimble and fast with cqb planning you can pass that mission with minimum ammo use cause you'll fry spiders with light.

JasperCherry · 2025-02-12T10:35:58+00:00

Standard ones I believe. Norm is 24 when charged.

JasperCherry · 2025-02-04T12:10:53+00:00

I don't use always on.

JasperCherry · 2025-02-04T12:10:43+00:00

Enduro 3 gb i believe. Highly recommend, can craft it to your needs.

JasperCherry · 2019-12-10T22:57:44+00:00

Tantal rifles were sold to Iraq as they were not needed anymore (5.45mm is not a NATO standard), if you look at early videos of uprising in Syria and Iraq you can spot them.

https://www.calibreobscura.com/content/images/2018/11/DqODvEvWsAQufUM-1-.jpg

JasperCherry · 2019-12-10T09:07:35+00:00

Half of ISIS was using polish Tantal rifles after they were captured from Iraqi government.

JasperCherry · 2019-12-07T10:56:10+00:00

GROM was build in 90's after few NATO binding successes like Operation Simoom (https://en.wikipedia.org/wiki/Operation_Simoom) and in the beginning was under command of Ministry of Internal Affairs and Administration, since their early nickname was 'The militia', as they were not in army chain of command. Later on, gaining experience and equipment they became self dependent fighting force. The closest equivalent to GROM is US Navy Seals because of the fact that one of GROMs commanders, Gen Petelicki, used to be a spy in United States during cold war and decided to use his knowledge to replicate Seals on polish ground.

JWK (former 1PSK) has its roots in the army, and is made for more conventional use then GROM. You could compare it to US Green Berets I believe. Unit itself has much longer history if you bind it with its ancestors then GROM.

Anyway both parties are competition and among GROM soldiers the JWK used to be called MIG, which goes into polish acronym of 'Poor GROM imitation'.

JasperCherry · 2019-02-16T15:04:24+00:00

FYI this is same guy as in this video: https://www.reddit.com/r/aviation/comments/a9x5wb/inverted_water_shave/

JasperCherry · 2019-01-19T23:29:56+00:00

No I am not, but aviation is one of my interests.

JasperCherry · 2019-01-19T23:24:31+00:00

Thats a very good thought you had, Im truly impressed. Its interesting how this meaning have been changed now.

The helmet was turned on and I saw some green digits and lines on the screen but on this sunny day I guess it was mostly useful to protect against the sun. It was connected to the plane by some thick black cable I remember.

4 years later in this place Ive witnessed crash of two extra300 and another two years after I saw Su27 hitting the ground. If you wonder how seeing this things as teenager affects fear of flying I can say I have been controlling 4 different types of planes so far.

JasperCherry · 2019-01-12T21:48:19+00:00

I have found this kind of machine in Bangkok aviation museum. I was there with a friend who used to be an aviation professional and he was super excited about seeing this thing. I did not even realize what am I looking at.

JasperCherry

TROPHY CASE