cibomahto
Matrix ghosting comparison
Digging deeper into the effects of driving this 32x16 led matrix. I'm turning on only the top pixel in each column (starting with one pixel, then two, then 4, etc), and for a really short time- roughly .04ns, then off for ~780ns before changing the address lines. I expect to see only the top pixel lit, however the entire column lights up, which means that there's a ton of ghosting, not only from one row to the next (which I would expect), but across all the addresses.
It's most certainly caused by a capacitive effect in the driver, but it seems fairly extreme. It's pretty dim so not noticeable under normal conditions (the above are 10 second exposures in a dark room), but starts to put a bound on the possible contrast ration and gamut of this matrix.
Matrix ghosting comparison
Digging deeper into the effects of driving this 32x16 led matrix. I'm turning on only the top pixel in each column (starting with one pixel, then two, then 4, etc), and for a really short time- roughly .04ns, then off for ~780ns before changing the address lines. I expect to see only the top pixel lit, however the entire column lights up, which means that there's a ton of ghosting, not only from one row to the next (which I would expect), but across all the addresses.
It's most certainly caused by a capacitive effect in the driver, but it seems fairly extreme. It's pretty dim so not noticeable under normal conditions (the above are 10 second exposures in a dark room), but starts to put a bound on the possible contrast ration and gamut of this matrix.