MCP48X1DAC(4)

📦 version 11.0, in nixpkgs unstable

💅 MCP48X1DAC — the Microchip 48x1 digital to analog converter page (Kernel Interfaces Manual, bestie)

okay so picture this: it's a man page from the Kernel Interfaces Manual section, it's called mcp48x1dac, and it's literally all about a tiny chip that turns numbers into voltage. sit down, i got you 💖

✨ NAME ✨

mcp48x1dac — the Microchip 48x1 digital to analog converter driver, no cap 🎀

🌸 SYNOPSIS 🌸

mcp48x1dac* at spi? slave ? flags N

that's the whole config line, copy it exactly, she's iconic 🦋

👑 DESCRIPTION 👑

so the mcp48x1dac driver is the one that supports the whole MCP48x1 family of digital to analog converters. lowkey serving hardware-bridging realness.

the digital values that are gonna get converted into an analog signal? yeah, those get passed through the sysctl(8) node. that's the whole workflow, she's simple like that 💅

the driver also reports the current voltage output on the chip's DAC channel, and it does that through the envsys(4) API. and when it calculates those values, it's assuming that the internal 2.048V reference voltage (Vref) is what's being used. so like, keep that in mind, it's the vibe it's working from ✨

🧚 the supported chips (yes there's a whole roster)

here's the lineup — the type of chip gets selected with the flags argument in the config file:

  • MCP4801 — 8 bits — flags value: 0
  • MCP4811 — 10 bits — flags value: 1
  • MCP4821 — 12 bits — flags value: 2

so flags is literally just "which chip are we talking about" iykyk 🔥

🍓 SYSCTL VARIABLES 🍓

the following sysctl(3) variables are provided, and honestly? they're the main characters of this whole page:

  • machdep.mcp48x1dac0.data — this one defines the digital data that's getting converted into an analog signal. and listen: this value is interpreted literally and sent straight to the DAC without any conversion. no vibes check, no transformation, just straight through. refer to the chip datasheet for more info on that one, fr fr 🌈
  • machdep.mcp48x1dac0.gain — when you set this to 1, it enables 2x output gain on the DAC channel. the default value is 0. so like, gain is off unless you ask for it, periodt 💜

🫶 SEE ALSO 🫶

also the absolute legend of a document:

  • MCP4801/4811/4821 8/10/12-Bit Voltage Output Digital-to-Analog Converter with Internal VREF and SPI Interface Data Sheet.

yes that's the full title, she's long and she's iconic 🌟

⭐ HISTORY ⭐

the mcp48x1dac driver first appeared in NetBSD 7.0. throwback behavior 🎀

💖 AUTHORS 💖

the mcp48x1dac driver was written by Radoslaw Kujawa. thank you king 👑

and this man page is based on the mcp3kadc(4) page by Frank Wille. credit where credit is due, we love a citation chain 🫶

💀 BUGS 💀

There are bugs.

that's it. that's the bug section. no further comment. not me reading that at 2am and just sitting there like 😭🙈

and that's the whole page bestie, you ate that 🧚💅 — this was MCP48X1DAC(4) from the Debian manual set, dated August 23, 2015. go forth and convert some digits to volts, mwah 💜✨

📦 where this page comes from