I was captivated by the introduction but I only made it halfway through before I gave up. The random bolding and emphasizing of almost every other word really put me off. Also, even though I can see that it's clearly had a ton of human effort put into it, I got a lot of AI vibes from the writing.
You can read it in the Medium frontend scribe.rip, to avoid some Medium shenanigans. I do think bolding stays the same though, it seems to have lots of bolding. Weird style.
That still won't do contactless payments, at least I don't think so.
It's a neat idea, to just move the chip. The final result isn't pretty, it would have been way cooler if the whole thing had fitted inside the watch, but there's not a lot of room in an F-91W.
Maybe someone with more experience with antenna designs could find a way to use the backplate as part of the antenna.
That's because the F91W was like Game Boy of watches. Or the Tetris under a 'Brick Game' branded cheap console. Every dad owned one. Reliable, cheap and damn long lasting.
You can get light spreader kits for the F91-W/A158W that replace the bit of plastic that sits behind the LCD for one that spreads the light from the LED far more evenly than the stock one.
I recently fitted one on my F91-W and it certainly makes a difference, but it's not going to make the light brighter like some of the other LED mods people have done.
n-o-d-e (blogger) has published many mods for this watch, with videos included. They have great production quality, and the mods are easy enough to pull off. https://n-o-d-e.net/casio.html
When I did this mod, I soldered the LED on its side, so that it shone directly onto the LCD. This made the watch face much brighter.
On reflection, the similar variant of the watch with an EL display is vastly superior. The A168 is similar to the A158 you mentioned but with a better light.
Cool project. Tip: acetone will readily dissolve the plastic parts of the card leaving the antenna(s) and chip intact. I believe a few other people have made drop-in PCBs with NFC antennas. Here’s one: https://n-o-d-e.net/datarunner.html
Also, no F-91W thread would be complete without a mention of the sensorwatch project: https://www.sensorwatch.net/
The dissolution in acetone is nicely demonstrated here https://youtu.be/NF4VJJKTjy8?t=835
The guy does it in order to be able to pay with a prosthetic eye.
I’ve been doing Apple Pay without issue with the phone since it started, and doing it without authentication since the Apple Watch came out. The (very) few issues wouldn’t be fixed by putting the system in a different case. Seems like a lot of work for nothing.
I watch a YouTube series of 2 guys who restored a classic Mini car (putting the running gear of another car into it, adding bells and whistles and more bells and whistles). They've been going at it 12 years, when they could've just bought a modern car. Seems like a lot of work for nothing.
Another good effort and well intentioned piece ruined by soulless AI writing.
If English is not your primary language, it’s ok. Rather write with mistakes and quirks: it would still feel more human and readable than a draft flattened and weakened by using chatGPT
I think going by the timestamp of the article and checking the article on a couple of AI detectors, that this article has a low probability of being written by GPT.
More than likely just translation anomalies from Italian to English.
The problem with this approach is, every once in a while - I think the bank sets the limit - the card will not accept any NFC transactions at all until a physical confirm-with-pin transaction is made.
That frankenstein'd chip... no way it can ever be assembled back into a "holder" card without risking everything breaking.
These F-91W projects inspired me to buy one, but I found it to be so small (and I don't have a particulary big wrist). So I gave it to my 12 year old and bought a W-217H, which is almost identical but larger.
I don’t know why Casio doesn’t just do something like this themselves, I’d buy it. Don’t need a super smart watch but do like contactless payment with a wrist.
> I thought it would be nice not to have to take out my credit/debit card from the wallet or my mobile phone from the pocket to pay, but instead, to bring the watch closer to the PoS and just pay with a pinch of modern-day magic .
I don't know, every time I see someone paying with their watch it looks super awkward when they have to twist their arm so the watch gets close enough to the reader.
Most of the time they are holding their phone in their other hand which makes the whole thing extra silly and unnecessary.
This is a really cool hack, and I wish I could pay for things with a dumb watch. It's just the right level of useful and silly to be up my alley. But the article, as others have mentioned, is a little off. The author did not "invent" the guess-and-check method for verifying resonance. That's been a staple of radio since the beginning, which is why original tuner dials were actually variable capacitors
> Therefore, an ideal antenna should consist of a 22.12 metre long wire, but by convention fractions of λ-lambda (λ/2, λ/4, λ/8, λ/16, etc.) are opportunely chosen.
This sentence is confused enough to be incorrect. λ/2 is generally preferred as an antenna length (standard dipole configuration) because it will resonate at the appropriate frequency with desirable standing wave characteristics (current maximum and zero voltage at input, voltage maximum and current minimum at ends). λ/4 can be used as a half-dipole, but it requires a ground plane to resonate properly. There are also arguments to be made for a 5λ/8 antenna, but none that I'm aware of for λ/8 or λ/16.
In practice for small antennas, physical length and electrical length are only tenuously related, so it's a matter of creating a circuit that acts like an antenna of the chosen length.
i love this and its something i had always wanted to try. I am actually kind of ticket off at chatgpt as i asked it about 6 months ago how something like this work and it told me it physically wasnt possible. maybe i need to improve my prompting.
Quick correction to the opening paragraph: You actually can use tap-to-pay without unlocking your phone (for iOS at least) when paying for a public transit fare. Theres a setting called transit mode or express or something. Once enabled, you just hold your phone up and it works without authenticating
35 comments
[ 5.0 ms ] story [ 56.3 ms ] threadChanging the CSS rule .jb { font-weight: 700; } to .jb { font-weight: 500; } got rid of all the bolded parts for me...
https://scribe.rip/infosec-watchtower/how-i-hacked-casio-f-9...
It's a neat idea, to just move the chip. The final result isn't pretty, it would have been way cooler if the whole thing had fitted inside the watch, but there's not a lot of room in an F-91W.
Maybe someone with more experience with antenna designs could find a way to use the backplate as part of the antenna.
https://en.wikipedia.org/wiki/Casio_F-91W#Usage_in_terrorism
I recently fitted one on my F91-W and it certainly makes a difference, but it's not going to make the light brighter like some of the other LED mods people have done.
When I did this mod, I soldered the LED on its side, so that it shone directly onto the LCD. This made the watch face much brighter.
On reflection, the similar variant of the watch with an EL display is vastly superior. The A168 is similar to the A158 you mentioned but with a better light.
Also, no F-91W thread would be complete without a mention of the sensorwatch project: https://www.sensorwatch.net/
More than likely just translation anomalies from Italian to English.
That frankenstein'd chip... no way it can ever be assembled back into a "holder" card without risking everything breaking.
While this is really impressive, putting something in front of the faceplate breaks the great F-91W look and feel for me.
I don't know, every time I see someone paying with their watch it looks super awkward when they have to twist their arm so the watch gets close enough to the reader.
Most of the time they are holding their phone in their other hand which makes the whole thing extra silly and unnecessary.
I still think this is a pretty cool project.
> Therefore, an ideal antenna should consist of a 22.12 metre long wire, but by convention fractions of λ-lambda (λ/2, λ/4, λ/8, λ/16, etc.) are opportunely chosen.
This sentence is confused enough to be incorrect. λ/2 is generally preferred as an antenna length (standard dipole configuration) because it will resonate at the appropriate frequency with desirable standing wave characteristics (current maximum and zero voltage at input, voltage maximum and current minimum at ends). λ/4 can be used as a half-dipole, but it requires a ground plane to resonate properly. There are also arguments to be made for a 5λ/8 antenna, but none that I'm aware of for λ/8 or λ/16.
In practice for small antennas, physical length and electrical length are only tenuously related, so it's a matter of creating a circuit that acts like an antenna of the chosen length.
Forget modifying the watch itself. Instead, build a strap add-on to hold the NFC payment chip and antenna.
Here is a project where I did something similar to carry a microSD memory card.
https://www.thingiverse.com/thing:6784665
https://www.theguardian.com/world/2011/apr/25/guantanamo-fil...
OR perhaps your meme is out of date.