I worked on deep sub-micron, full custom mixed-signal integrated circuits for more than a decade, and I can't pass the first level.

> Wire an NMOS transistor so that when In is 1, the output is pulled to ground (0). When In is 0, the output should be unconnected (Z).

Certainly:

(a) The nMOS has 3 connections: its drain is only connected to the output (no +Vdd supply), it's source is tied to ground, it's gate is tied to the signal input

(b) When the gate (input) is driven high, the nMOS transistor turns "on," connecting the output to the source (which is grounded). This acts as a "pull-down network"

(c) When the gate is driven low, the nMOS turns "off," leaving no connection to the output. This is equivalent to a "high-impedance" / "unconnected" / "Z" output

Fails 1/2 tests

(Edit) - I thought the light grey, thick line on the background grid was a wire from "input" to the transistor's gate. It is not. You need to explicitly add a wire from "input" to gate :\

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mistidoi 8 hours ago | parent | next [-]

I'm a total doofus with no relevant experience and neither could I.

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Jaso1024 8 hours ago | parent [-]

Adding intro levels today!

	▲	djmips 2 hours ago \| parent [-]
		I solved it but I had to use 'two' NMOS transistors unlike the direction. Wire an NMOS transistor so that when In is 1, the output is pulled to ground (0). When In is 0, the output should be unconnected (Z). The way it's worded it sounds like you need 'an NMOS' ie a single one? So I messed around but then I remembered seeing gates made from two transistors in my dusty memory. (edit) I see there _is_ a one transistor solution... I'm pretty sure I tried that though. :/

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Jaso1024 8 hours ago | parent | prev | next [-]

lol, mb. As in understand it, its that the colors of the bg make it seem like its wires when its not, I'll change the color theme a bit to fix (plz correct me if my understanding is wrong)

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roadbuster 8 hours ago | parent | next [-]

Yes, that's the issue: the (thick) solid grey "major axis" lines on the background seemed to be a wire.

If I could make a recommendation, get rid of the grid lines entirely and only have 'dots' at regular spacing. Here's what Cadence Virtuoso looks like (the most popular circuit schematic tool for integrated circuit design):

https://www.eecs.umich.edu/courses/eecs311/f09/tutorials/cad...

	▲	Jaso1024 8 hours ago \| parent [-]
		Will do, thx! Coming in the next push

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varenc 4 hours ago | parent | prev | next [-]

consider a colorblind mode that uses patterns instead of colors for those of us that are color-challenged

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dcreater 4 hours ago | parent | prev [-]

the part that tripped me up is 0 showing in deep RED and I thought that meant I was doing something wrong. I came here, read this and realized I was actually right and then pressed the Run tests button and passed. This is a UX thing you'd want to address

	▲	Jaso1024 2 hours ago \| parent [-]
		makes sense, ill change the color a bit in the next update

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brcmthrowaway 5 hours ago | parent | prev [-]

Did you switch to software?

	▲	roadbuster 33 minutes ago \| parent [-]
		Yes. But, looking at BRCM/AVGO's stock chart, I may have made a mistake.