Recent content by bremenfallturm

Hi! I am struggling with the exercise I mentioned under "Homework statement". The exercise is about a specific "greedy vertex coloring algorithm". One definition (which matches what my book uses) can be found here: https://people.cs.uchicago.edu/~laci/HANDOUTS/greedycoloring.pdf Here is also...

Mhrm, oops. Sorry... I drew the schematics wrong - this is what I intended to show you Where the circuit comes from: I was inspired by the circuit below, which is presented in the book Practical Electronics For Inventors, p. 875. The book says that the circuit diagram is from Freetronic's...

Hi. I am building a project where I have a microcontroller (Attiny44A) connected to some buttons. All the buttons are connected via one ADC pin, and pressing different buttons give different voltages. I have posted topics about this circuit before. I have also successfully breadboarded it, but...

I am trying to understand how QQ plots work, but I have a hard time understanding how to interpret skewness. Specifically, it is "the other way around" than I expect. Let me explain. From what I understand, in a QQ plot, we divide the normal distribution (typically ##N(0,1)##) and the dataset...

Thank you! I understand now.

Sorry for the rookie follow-up question then, but why is that so? Is it because the potential at the point where the first switch is connected is 0V after it has been pulled to ground, and there is no potential difference between that point and concequtive points after pulling to ground?

Hi, I'm trying to build an ADC circuit with a varying voltage on the ADC pin depending on which switch is held down. I have been thinking about the edge case where multiple switches are held down, and what would happen. In the circuit below, all 4 switches are held down. I would assume that...

Alright, I see your point. Am I correctly understanding that my duty cycle would be ##\frac 1 {12}##? What I currently do is that I cycle between all 12 pin states with a delay of 1ms between each of them. This would mean that one LED is on for ##\frac{1 \text{ms (each LED's individual...

Hi! I am trying to create a circuit which can individually turn on and control 12 LEDs from 4 pins, since I am trying to adapt it to a tiny microcontroller (the Attiny85, which does not have enough pins to drive the LEDs) For this, I am using a method called Charlieplexing. You can for example...

Many deep thanks to everyone who replied here! It was indeed a software issue in the end :) All looks good now after I made some improvements to the software. No brightness issues.

Hi! I am questioning my design choices, but I will try to push this circuit a little more until I get a microcontroller with more pins and don't use Charlieplexing. Charlieplexing is a method of controlling n*(n-1), in this case LEDs, using n GPIO pins. This is achieved by alternating the...

Ah ok, sounds very reasonable. Thank you for the clarification. And it is never possible to get "sufficient voltage present" to light up both the two leftmost series LEDs and the second LED to the right? Just trying to wrap my hand around why we don't get sufficient voltage on those two.

Hello! Forgive me for this absolute beginner question. I was trying to experiment with Charlieplexing a couple of LEDs. Charlieplexing is a technique that utilizes the fact that many microcontrollers attend a high impedance state when set to input and of course that diodes only pass current one...

Follow-up question: why can not sw t1, 0(s) and ori t1, t0, 7 be in the same slot? I would assume that the result of ori could be forwarded to the beginning of the M stage of the sw instruction? Trying to illustate this with a little arrow: ...........| ........... F D E V M W #sw F D E . M W...

Oh yeah, definitely not. Thanks for the pointers in the right direction? Now I'm just left with a curious bonus question (feel free to fill in if you have time ;))