[HN Gopher] Programming a CH32v003 with light
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       Programming a CH32v003 with light
        
       Author : blutack
       Score  : 97 points
       Date   : 2024-08-02 11:00 UTC (12 hours ago)
        
 (HTM) web link (mitxela.com)
 (TXT) w3m dump (mitxela.com)
        
       | netrap wrote:
       | Damn that is cool.
        
       | blutack wrote:
       | There's also a short associated YouTube video showing it in
       | action.
       | 
       | https://youtu.be/IHD3ji-F600
        
       | voidUpdate wrote:
       | If you've not seen any of Mitxela's stuff before, I'd check out
       | more of their website and their youtube channel, they do some
       | really fun stuff
        
         | bitwrangler wrote:
         | I didn't realize this was the same creator of the tiny LED
         | matrix earrings. I love the attention to detail in the work and
         | the article. Super interesting!
         | 
         | https://mitxela.com/projects/ledstud
        
       | yjftsjthsd-h wrote:
       | So it's cool regardless and I have to think that it has some
       | benefits, but I have to ask... What's the benefit over pogo pins,
       | especially for programming the chip? I guess less special
       | hardware on the computer doing the programming?
        
         | monocasa wrote:
         | I'm not sure if it's useful in this incarnation, but I am
         | reminded of the localizers in A Deepness in the Sky, an early
         | description of smartdust which were relatively omnipresent and
         | capable of communicating and being reprogrammed by light
         | patterns.
        
         | theamk wrote:
         | There is no special hardware at all, which is a _huge_ deal.
         | 
         | This is especially important for consumer devices like badges.
         | Anyone can find a device with screen that can run a webpage,
         | but very very few people would have a right programmer with
         | right pogo pins.
         | 
         | Plus, pogo pins at less than .100" spacing are pretty fragile,
         | and the projects author uses are so small they'll need a much
         | finer pitch.
        
       | londons_explore wrote:
       | Have you considered a positive feedback capacitor with the op-
       | amp, to try to make an oscillator?
       | 
       | Then the illumination on your LED will affect the phase of the
       | oscillator. By trying to make it oscillate at ~10Mhz, and then
       | sampling the data, you should avoid the clipping problem, and
       | you'd have a lot more data to use to potentially extract
       | interesting things with clever math.
       | 
       | Even if the oscillator runs at 10Mhz, you don't have to sample at
       | 10 Mhz - you could sample at a lower frequency (which must be
       | clock cycle accurate) and make use of aliasing to still measure
       | phase shifts very accurately.
       | 
       | You're totally going to measure the power supply, temperature,
       | radio signals and a whole host of other things at the same time,
       | but with the right signal processing/modulation you should be
       | able to extract the effects you need.
        
         | blutack wrote:
         | Sorry I'm not mitxela, I just find pretty much all their
         | projects old school hacker awesome.
         | 
         | Good suggestion but from their article it seems like there's
         | some really odd silicon level interactions going on so who
         | knows? Might be worth getting a CH32v003 and finding out!
        
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       (page generated 2024-08-02 23:01 UTC)