It's more or less widely known that especially high-capacitance ceramic capacitors have significantly less capacitance at their rated voltage than at 0V. While this effect is detrimental for bypass applications, has anyone ever turned that effect into something useful?
I was thinking of using this effect to make a variable capacitor for a VCO or maybe getting some use out of the non-exponential RC charge characteristic.
@gsuberland@karotte
Unfortunately I think it is likely too temperature dependent to do that.
But it could be interesting to see.
A 1:47AM thought, could the body diode be used to measure the die temperature?
Then you'd have the built in temperature sensor for temperature compensation as well.
But back to DTC's. So far all of them that I have seen used a pile of switched capacitors.
Or were just ST8P switches with "bring your own capacitors".
@ftg@karotte hmm, possibly if the package has a separate body terminal? although I don't know if the forward IV curve or reverse leakage current over the body diode varies with Vds or Vgs in the subthreshold region.
So you're developing a cross-platform library that deals with filenames as a const char * (or the equivalent thereof)? On Windows, please treat the the filenames as UTF-8 and internally convert them to UTF-16 to call the Unicode Windows APIs or only have a wchar_t* function available.
DO NOT pass the filename as-is to the ANSI Windows APIs. With char * being treated as UTF-8 encoded text, this appears to work until an umlaut or another non-ASCII character appears in a filename.
@karotte yes; the older *A functions (e.g. CreateFileA) expect a Windows-1252 (ISO 8859-1 superset) string. that codepage does contain many accented characters, but it is not byte-compatible with UTF-8 so passing UTF-8 strings in will bite you in the ass.
use MultiByteToWideChar to convert UTF-8 to UTF-16, then call the *W suffixed API rather than the *A suffixed API.
@karotte I've become quite lazy these power modules are awesome and come with the inductor integrated. The one in the image is from Würth and they are somewhat pricey but MPS has ones for just a dollar which is nice.
I've been using the Murata MYMGK series a lot lately. They're... A little larger than the ones in your photo. But for a large FPGA or something they're great.
Introducing USBKVM! A keyboard, screen and mouse that all fit in your the palm of your hand!
It's built around the MS2109 HDMI to USB capture chip and its I²C interface connected to an STM32 MCU that takes care of the keyboard and mouse emulation.
While the hardware is fully functional, firmware and software are in a proof-of-concept stage. Stay tuned…
A couple of shitposts on my timeline about the link protocol used by TI calculators reminded me about an oddity of it that I haven't seen elsewhere:
It's a two-wire (red, white, GND) open-drain interface. One might assume, that one wire's clock and the other one is data or that one's RX and the other one is TX. However, it's none of that:
To transmit a '1', the sender pulls the white line low, the receiver acknowledges this by pulling the red line low. The sender then releases the white line and the receiver finally releases the red line. For transmitting a '0', the sender starts with pulling the red wire low.
This has the nice property that it does bit-level handshaking and flow control and is self-clocking.
Despite these advantages, I've never seen such kind of protocol used anywhere else. If you have, let us know!
Now that's a first: Ordered some hard-to-find chips from China and they came with the marking lasered off 🤨
I did some cursory checks for connectivity of multiple GND/VCC pins and ESD diodes and it all checks out with the expected pinout. So either someone spent a lot of effort making a counterfeit or they're actually genuine.
I've prepared a preliminary release of Dune 3D for everyone to make sure that they'll be able to package the upcoming 1.0 release without any bad surprises: https://github.com/dune3d/dune3d/releases/tag/v0.9.3