a thread about janitoring individual bits and using oscilloscopes and stuff

The Something Awful Forums > Discussion > Serious Hardware/Software Crap > YOSPOS > a thread about janitoring individual bits and using oscilloscopes and stuff

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Silver Alicorn: Mar 30, 2008; 𝓪 𝓻𝓮𝓭 𝓹𝓪𝓷𝓭𝓪 𝓲𝓼 𝓪 𝓬𝓾𝓻𝓲𝓸𝓾𝓼 𝓼𝓸𝓻𝓽 𝓸𝓯 𝓬𝓻𝓮𝓪𝓽𝓾𝓻𝓮

snype

# ? Nov 26, 2014 01:19

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# ? Apr 16, 2024 06:09

Jonny 290: May 5, 2005; [ASK] me about OS/2 Warp

i brought my $3 soldering iron to colorado, oh and a DMM. i dont have any diy inventory though i STILL need to spend like 1k to get things goin

good thred

# ? Nov 26, 2014 01:21

Bloody: Mar 3, 2013

I own no equipment so it owns Workin in a lab with like 100k network analyzers n metcal irons n poo poo

Not that I ever take advantage of this

Might for Santee though!

# ? Nov 26, 2014 01:42

The Management: Jan 2, 2010; sup, bitch?

Werthog 95 posted:

lol when hobbyists roll in and tell you "avr supremacy" just because that's what arduinos use

# ? Nov 26, 2014 02:20

The Management: Jan 2, 2010; sup, bitch?

better than accumulator architectures, I guess. but seriously, use a cortex M0/3

# ? Nov 26, 2014 02:24

sleepy gary: Jan 11, 2006

I make quantum cascade lasers

# ? Nov 26, 2014 02:27

ChiralCondensate: Nov 13, 2007; what is that man doing to his colour palette?; Grimey Drawer

I (in a team with others) janitor these bits:

the cms forward pixel detector

# ? Nov 26, 2014 02:33

Bloody: Mar 3, 2013

ChiralCondensate posted:

I (in a team with others) janitor these bits:

the cms forward pixel detector

dope

# ? Nov 26, 2014 02:42

movax: Aug 30, 2008

ChiralCondensate posted:

I (in a team with others) janitor these bits:

the cms forward pixel detector

# ? Nov 26, 2014 05:04

maniacdevnull: Apr 18, 2007; FOUR CUBIC FRAMES
DISPROVES SOFT G GOD
YOU ARE EDUCATED STUPID

Werthog 95 posted:

lol when hobbyists roll in and tell you "avr supremacy" just because that's what arduinos use

ug, loving casuals

idk man it was cheap and easy to get into even before arduinos, beg for free chips i mean 'engineering samples' from manufactures and rig the rest up from old parts a packrat cj already has

# ? Nov 26, 2014 05:10

GameCube: Nov 21, 2006

at my internship i wrote a driver for an ISA card, and i'm going to call myself an embedded engineer for the rest of my life for it.

# ? Nov 26, 2014 05:13

EIDE Van Hagar: Dec 8, 2000; Beep Boop

i have this thing working now, i re-wrote some of the stuff in the adafruit arduino libraries to use the galileo board, but its quick and dirty, not as nice as the arduino gfx stuff in their libraries. it will show 4096 colors though, and i am working on making it display arbitrary bitmaps, the drawings on it are all just lines i wrote manually. i actually had to slow it down by adding a counter in the bit count modulation logic compared to the arduino libs. the arduino spends enough time drawing framebuffers that it leaves the LED on for a while, the quark was turning the led off so fast that the same programming sequence didn't work, i had to add some time to leave the LEDs on before i started programming the matrix again:

# ? Nov 26, 2014 05:21

Bloody: Mar 3, 2013

beep boop lmao

# ? Nov 26, 2014 05:25

Bloody: Mar 3, 2013

wish/hope im your santee

# ? Nov 26, 2014 05:25

EIDE Van Hagar: Dec 8, 2000; Beep Boop

that union jack looking thing is just a test pattern i made so i could see which rows and columns are in the wrong place while I was fixing the timing. you can now draw an arbitrary graphics plane like from a bitmap or a gif or ppm and feed it into the planes and update the pointers to the plane you want using a counter. right now it has 4 framebuffers each capable of 4096 colors or fewer depending on how you set up color depth at compile time. point a framebuffer at an animated gif frame and you could set a counter to update whatver times per second or whatever

beep boop

# ? Nov 26, 2014 05:52

EIDE Van Hagar: Dec 8, 2000; Beep Boop

Bloody posted:

wish/hope im your santee

its not you but it is another well known shamefully nerdy yosposter. if you want i can post my source code to be ridiculed, i am a bad c++ programmer and i am sure i write it all as if it were system verilog and everything happens in zero simulation time with no regard for actual resources.

# ? Nov 26, 2014 05:54

CISADMIN PRIVILEGE: Aug 15, 2004; optimized multichannel
campaigns to drive
demand and increase
brand engagement
across web, mobile,
and social touchpoints,
bitch!

beep boop you rule mr kwinkles.

# ? Nov 26, 2014 05:56

Bloody: Mar 3, 2013

kwinkles posted:

its not you but it is another well known shamefully nerdy yosposter. if you want i can post my source code to be ridiculed, i am a bad c++ programmer and i am sure i write it all as if it were system verilog and everything happens in zero simulation time with no regard for actual resources.

tbf thats probably better than average

# ? Nov 26, 2014 05:58

Bloody: Mar 3, 2013

wheres the cheapest place to get loose tolerance full panel 1 or 2 layer boards

im not interested in toner transfer

# ? Nov 26, 2014 05:58

EIDE Van Hagar: Dec 8, 2000; Beep Boop

i will post the full source when i actually have it drawing animated gifs and doing useful things. for now this is how i drew the test pattern:

code:


    for (int column = 0; column < PLANE_COLUMNS; column++) {
      for (int row = 0; row < PLANE_ROWS; row++) {
        // test pattern because i don't know what rows are wrong and where the timing is hosed
        // this should basically look like a combination of the rainbow flag and union jack
        
        // make the top and bottommost rows red, green just inside
        // top is bright as you can get and bottom is dim
        if (row==0) {
          r=0xf;
        }
        if (row==15) {
          r=0x1;
        }
        if (row==1) { 
          g=0xf;
        }
        if (row==14) {
          g=0x1;
        }
        
        // make the left and right columns blue, purple just inside, left side bright
        // and right side dim.  what about where the rows and columns intersect in the corners?
        // we just don't care, whichever thing we drew last wins
        if (column==0)  {
          b=0xf;
        }
        if (column==31) {
          b=0x9;
        }
        if (column==1) {
          b=r=0xf;
        }
        if(column==30) {
          b=r=0x1;
        }
        // draw a yellow and blue x intersecting in the middle of the panel #woah
        if (column == 2*row) {
          g=r=0xf;
        }
        if (column == -2*row+32) {
          g=b=0xf;
        }
        
        // draw a 2 pixel wide white and pinkcross in the middle of the panel 
        // make it pink because pink is pretty
        if (column==15 || row==8) {
          b=g=0xA;
          r=0xF;
        }
        if (row==7 || column==16) {
          b=r=g=0xA;
        }
        
        for (int color = 0; color < PLANE_COLORS; color++) {
            if (color == PLANE_RED)  {
              planes[plane][column][row][color] = r;
            }
            if (color == PLANE_GREEN)  {
              planes[plane][column][row][color] = g;
            }
            if (color == PLANE_BLUE)  {
              planes[plane][column][row][color] = b;
            }
        }
        r = b = g = 0;
      }
    }
    for (int row = 0; row < PLANE_ROWS; row++) {
      for (int column = 0; column < PLANE_COLUMNS; column++) {
           if (row<8) {
              buffer[column][row][BUF_R1] = planes[plane][column][row][PLANE_RED];
              buffer[column][row][BUF_G1] = planes[plane][column][row][PLANE_GREEN];
              buffer[column][row][BUF_B1] = planes[plane][column][row][PLANE_BLUE];
           } else {
              buffer[column][row-8][BUF_R2] = planes[plane][column][row][PLANE_RED];
              buffer[column][row-8][BUF_G2] = planes[plane][column][row][PLANE_GREEN];
              buffer[column][row-8][BUF_B2] = planes[plane][column][row][PLANE_BLUE];
           }
      }
    }

# ? Nov 26, 2014 06:17

EIDE Van Hagar: Dec 8, 2000; Beep Boop

i am sure there is a better way to do that probably involving making the buffer a pointer to the plane or something so i can just change where in memory the image i want actually lives but hell if i know how to do that! especially when reformatting the plane into a buffer that has two rgb pixels 8 pixel rows apart in each buffer line.

# ? Nov 26, 2014 06:30

rotor: Jun 11, 2001; classic case of pineapple derangement syndrome

Quality Thread

# ? Nov 26, 2014 06:32

z0rlandi viSSer: Nov 5, 2013

Bloody posted:

beep boop lmao

# ? Nov 26, 2014 06:42

z0rlandi viSSer: Nov 5, 2013

kwinkles posted:

its not you but it is another well known shamefully nerdy yosposter. if you want i can post my source code to be ridiculed, i am a bad c++ programmer and i am sure i write it all as if it were system verilog and everything happens in zero simulation time with no regard for actual resources.

lmfao who gives a poo poo as long as it works

this isn't the 1970's and we have cycles to fukkn spare like woah

# ? Nov 26, 2014 06:43

Bloody: Mar 3, 2013

z0rlandi viSSer posted:

we have cycles to fukkn spare like woah

your in the wrong thread m8

# ? Nov 26, 2014 06:47

EIDE Van Hagar: Dec 8, 2000; Beep Boop

right now it updates the display in the arduino sketch loop like this:

code:

void loop() {
  
  for (int bcmBit = 1; bcmBit < (BIT_DEPTH+1); bcmBit++) { // which bit value we are using for BCM
    for (int iter = 0; iter < bcmBit; iter++) {            // how many iterations this bit gets
      for ( int row = 0; row < BUFFER_ROWS; row++ ) {      // update each row
    
        for (int wait=0; wait<50;wait++) {
          fastGpioDigitalWrite(OE,LOW);
        }
        
        fastGpioDigitalWrite(OE,HIGH);
        
        // set the address bits
        if ( row & 0x1 ) {
          fastGpioDigitalWrite(A,HIGH);
        } 
        else {
          fastGpioDigitalWrite(A,LOW);
        }
        if ( row & 0x2 ) {
          fastGpioDigitalWrite(B,HIGH);
        } 
        else {
          fastGpioDigitalWrite(B,LOW);
        }
        if ( row & 0x4 ) {
          fastGpioDigitalWrite(C,HIGH);
        } 
        else {
          fastGpioDigitalWrite(C,LOW);
        }
       
        
        for ( int column = 0; column < BUFFER_COLUMNS; column++ ) {
          
          if (0x1 & (buffer[column][row][0]>>(bcmBit-1))) {
            fastGpioDigitalWrite(GPIO_FAST_IO0,HIGH);
          } 
          else {
            fastGpioDigitalWrite(GPIO_FAST_IO0,LOW);
          }
          if (0x1 & (buffer[column][row][1]>>(bcmBit-1))) {
            fastGpioDigitalWrite(GPIO_FAST_IO1,HIGH);
          } 
          else {
            fastGpioDigitalWrite(GPIO_FAST_IO1,LOW);
          }
          if (0x1 & (buffer[column][row][2]>>(bcmBit-1))) {
            fastGpioDigitalWrite(GPIO_FAST_IO2,HIGH);
          } 
          else {
            fastGpioDigitalWrite(GPIO_FAST_IO2,LOW);
          }
          if (0x1 & (buffer[column][row][3]>>(bcmBit-1))) {
            fastGpioDigitalWrite(GPIO_FAST_IO3,HIGH);
          } 
          else {
            fastGpioDigitalWrite(GPIO_FAST_IO3,LOW);
          }
          if (0x1 & (buffer[column][row][4]>>(bcmBit-1))) {
            fastGpioDigitalWrite(GPIO_FAST_IO4,HIGH);
          } 
          else {
            fastGpioDigitalWrite(GPIO_FAST_IO4,LOW);
          }
          if (0x1 & (buffer[column][row][5]>>(bcmBit-1))) {
            fastGpioDigitalWrite(GPIO_FAST_IO5,HIGH);
          } 
          else {
            fastGpioDigitalWrite(GPIO_FAST_IO5,LOW);
          }
          fastGpioDigitalWrite(CLK,HIGH);
          fastGpioDigitalWrite(CLK,LOW);
         }   
        
        // latch data
        fastGpioDigitalWrite(LAT,HIGH);
        fastGpioDigitalWrite(LAT,LOW);
        
        fastGpioDigitalWrite(OE,LOW);
        
      }
    } 
  }
}

the loop where it writes to the OE (output enable) bit low 50 times in a row is the part i had to add to make it slow down. basically it tells the LEDs to stay on 50 times (output enable is active-low) in a row.

fastGpioDigitalWrite calls happen at about 600kHz. There is also a function fastGpioDigitalRegWriteUnsafe that requires you to keep track of register bits and writes destructively to the gpio registers, but i haven't figured out how to use all of that yet. fastGpioDigitalRegWriteUnsafe will push the clock from about 600 kHz to 2.9MHz, which could allow for something awesome lile RGB565 16-bit color.

# ? Nov 26, 2014 06:54

EIDE Van Hagar: Dec 8, 2000; Beep Boop

the bcmBit and iter loops are for binary code modulation. for the least significant bit it runs through the display loop (the "iter" or iteration loop) once. for the 2nd least significant bit it runs through the loop twice, and so on for each binary bit position.

basically, the more significant the bit in your binary value, the more times it loops through displaying that bit. the LED is on if it is a 1 and the LED is off it is a zero, so it displays the LSB once and the MSB however many times there are bits in the number. So basically your duty cycle depends on the MSB proportionally more than the LSB, so you end up with a duty cycle representative of the actual binary number.

if you look at that test pattern image, you can see that the bottom and rightmost pixels rows/columns are dimmer than the left and top rows/columns. that's 4 bits per r/g/b channel, or 12 bits per pixel, or 4096 colors total.

beep boop.

# ? Nov 26, 2014 07:01

EIDE Van Hagar: Dec 8, 2000; Beep Boop

fun fact 16 bit color is 565 because your eyeball is most sensitive to green so you put the most bits there.

this is why digital cameras with bayer sensors sample 2 green pixels for each blue and red pixel and interpolate the results.

in my real job i make display, graphics and camera hardware so this arduino stuff was disturbingly familiar.

also the adafruit people did a good job of figuring out how these panels work. even if its not documented officially the fact that their libraries work show you how it needs to be clocked.

# ? Nov 26, 2014 07:14

movax: Aug 30, 2008

z0rlandi viSSer posted:

lmfao who gives a poo poo as long as it works

this isn't the 1970's and we have cycles to fukkn spare like woah

Nah man every cycle counts

I finished a FPGA design lately where I had to essentially pick and choose and place each primitive by hand. a more painful asic

# ? Nov 26, 2014 07:15

EIDE Van Hagar: Dec 8, 2000; Beep Boop

Bloody posted:

dope

explain this right now. how do it work? what is a compact muon solenoid?

# ? Nov 26, 2014 07:19

SpaceAceJase: Nov 8, 2008; and you
have proved
to be...

a real shitty poster,
and a real james

put an arduino on it

# ? Nov 26, 2014 08:52

eschaton: Mar 7, 2007; Don't you just hate when you wind up in a store with people who are in a socioeconomic class that is pretty obviously about two levels lower than your own?

Bloody posted:

but what if i want to get data in/out faster?? how do i do like real usb or ethernet as painlessly as possible??

some sort of fpga would be my first choice. they can be inexpensive (for prototyping anyway) and have blocks for all sorts of things like USB, Ethernet, HDMI, etc.

# ? Nov 26, 2014 11:49

The Management: Jan 2, 2010; sup, bitch?

z0rlandi viSSer posted:

this isn't the 1970's and we have cycles to fukkn spare like woah

a thing high level software people actually think

# ? Nov 26, 2014 18:02

eschaton: Mar 7, 2007; Don't you just hate when you wind up in a store with people who are in a socioeconomic class that is pretty obviously about two levels lower than your own?

I'm hoping my miniSpartan 6+ LX ships soon, I should start hacking together a VHDL description of NuBus for it

I ordered it because it had both a ton of GPIO and HDMI out, my goal is to make a video card for my Mac IIci that can handle 1920x1080. I'll be able to connect it almost directly to the NuBus, just adding bidirectional level conversion, and everything else can be done in "software"

# ? Nov 26, 2014 22:22

Sagebrush: Feb 26, 2012

The Management posted:

a thing high level software people actually think

i was gonna say "the android motto"

# ? Nov 26, 2014 22:53

Tin Gang: Sep 27, 2007; Tin Gang posted:
showering has no effect on germs and is terrible for your skin. there is no good reason to do it

this thread has got me itching and now I want to learn ARM microcontrollers

is this a good idea/what should I buy?

# ? Nov 27, 2014 01:12

EIDE Van Hagar: Dec 8, 2000; Beep Boop

Tin Gang posted:

this thread has got me itching and now I want to learn ARM microcontrollers

is this a good idea/what should I buy?

you should buy an intel brand galileo board in my extremely biased opinion.

# ? Nov 27, 2014 01:45

Sagebrush: Feb 26, 2012

You should buy an arduino if you're looking for the easiest and most straightforward way into microcontroller programming at a hobbyist level. The one board gives you everything you need and can operate as an ISP once you get enough electronics knowledge to work with discrete chips.

People slag arduino all the time because people build dumb projects with them while they're learning, but it is designed to be a learning tool and it's fantastic at that.

Sagebrush fucked around with this message at 01:53 on Nov 27, 2014

# ? Nov 27, 2014 01:49

movax: Aug 30, 2008

eschaton posted:

I'm hoping my miniSpartan 6+ LX ships soon, I should start hacking together a VHDL description of NuBus for it

I ordered it because it had both a ton of GPIO and HDMI out, my goal is to make a video card for my Mac IIci that can handle 1920x1080. I'll be able to connect it almost directly to the NuBus, just adding bidirectional level conversion, and everything else can be done in "software"

spartan bro

gonna do some hdmi overlay type stuff with mine though -- i hope the signal integrity isn't terrible on the board, most kickstarters suck rear end at laying out pcbs and fall over in the transition from maker fun toy to actual product

actual quote from a maker i ran into: 'controlled impedance? what's that?' (board had ddr3, usb, ethernet, hdmi) last i heard they were suffering 'difficulties' getting kickstarter stuff sorted

# ? Nov 27, 2014 01:58

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# ? Apr 16, 2024 06:09

EIDE Van Hagar: Dec 8, 2000; Beep Boop

lol if you dont have a PHY with dynamic impedance compensation.

# ? Nov 27, 2014 02:22

The Something Awful Forums > Discussion > Serious Hardware/Software Crap > YOSPOS > a thread about janitoring individual bits and using oscilloscopes and stuff

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