I have two interesting ideas. I have an old Optima typewriter, which has been produced since 1950 in the German Democratic Republic in Erfurt on the basis of the Olympia Büromaschinenwerke company. I want to breathe a second life into it and make it so that it can be connected to a computer or to another device such as a phone or tablet. I think the Arduino will be enough for this.

I also have an old Soviet film camera "Chaika", these cameras were produced in 1965-1974 by the Minsk Mechanical Plant named after SI Vavilov in Bellarusia. I want to make a retro digital camera out of it. I want to try to put a Raspberry PI and a camera module in it.

Perhaps take a look at this mechanical typewriter project for some ideas:

The Arduino Typewriter

https://www.youtube.com/watch?v=g8Sm4_yuImg

Coding on the Arduino typewriter

https://www.youtube.com/watch?v=npX0_vBZtCI

Turns a mechanical typewriter into a computer keyboard using an Arduino Leonardo as a USB HID.

Frankly, I think it won't work. Too near the tags, too difficult to discriminate, RFID is built to be activated by an emitter that provides the minimum current needed to the tag chip to send back its id. Keys are too net to risk this way. Then, again, I don't like to put something OVER the keys. Then, I don't trust too much that the reaction time is acceptable for a decent writing speed (about 200 char per minute), almost impossible to over 300 char per minute.

balearicdynamics

I have 2 ideas:

one: the typewriter uses metal keys, in theory a hall sensor or something can be used to detect these, but that might not be possible due to interference from other keys, and you could also add a tilt sensor(like that glass thing with metal ball), attached so that when you press on it it makes the connection pass through, and you can log the instance.

Or, membrane switches.

I think that the tilt sensor way is the most promising, but also quite complex, as you'll need tons of those.

Between those you mentioned, I agree that the tilt sensor may be better. I have used them in past and they are not so precise, at least those cheap, commercial ones. BTW, modern tilt sensors have plastic package, less delicate than glass.

Oh well, I guess I am behind on technology!

I saw how they work, if you put one somewhat upright... it might work. It might take you a few tries, and chances are, it won't be suitable.

You could also use one of those "tap" sensors.

Or even vibration... no that's not a very good idea

I have once again come with an idea.

I was browsing through adafruits sensors.

https://www.adafruit.com/product/1766

In theory, you could take one of these, probably the second(1767), which is hard to trigger, and... (in theory) it would trigger the switch once you hit down the key, since typewriters require some force.

(Of course, this is all theoretical)

I have once again come with an idea.

I was browsing through adafruits sensors.

https://www.adafruit.com/product/1766

In theory, you could take one of these, probably the second(1767), which is hard to trigger, and... (in theory) it would trigger the switch once you hit down the key, since typewriters require some force.

(Of course, this is all theoretical)