Cycling LED Modes using ControllerMate - algorithm

I'm using ControllerMate with a Nostromo (Belkin) n52 (NOT the te version) Speedpad on an iMac running Snow Leopard.
The official SpeedPad configuration software doesn't run beyond Tiger, or at least, it doesn't run on Snow Leopard due to the kext failing to load properly, hence the attempt at using ControllerMate.
The official SpeedPad configuration software has the capability to load 1 unique set of keys per "page", where there are 4 pages. This ultimately led me to be able to do things like basic key mapping on the first page, key combinations on the second, macro'ing on the third, and I set up some global shortcuts for my music player, and bound those same shortcuts on the last page of the Speedpad.
Pages were represented by the currently lit LED on the unit;
No LEDs On / Red LED On / Green LED On / Blue LED On
I'm attempting to use the Logic functions of ControllerMate in order to recreate this same behavior. Clicking a button bound to this routine will cause the LEDs to start cycling in the order listed above, ultimately circling around and restarting at no LEDs on.
I'm going to explain this as best I can so that the basic principles of programming/logic here could feasibly be answered by any individual here, but I might fail, and you might need to familiarize yourself with ControllerMate first :P.
ControllerMate presents you with a grid, where you simply drag objects in. It's a visual programming canvas. For example, my Canvas has 4 blocks on it currently;
Nostromo SpeedPad 2
Keypad LeftAlt
This is the key that corresponds to the large Orange button above the DPad. It's on the Canvas so I can dump other elements into it, and get elements out of it.
It's a basic Input/Output system with snapping elements.
Num Lock
Caps Lock
Scroll Lock
These represent the LEDs. When these blocks turn "on", the related LED on the SpeedPad lights up.
For example, if I connect one Lock block, or all of them, directly to the LeftAlt block, pressing the "LeftAlt" button on the SpeedPad turns on one/all of the LED light(s) for the duration that it's held.
ControllerMate actually has a wonderful guide of explaining the "Blocks" and showing what they look like at http://www.orderedbytes.com/controllermate/help/?show=blocks
The Logic blocks I have to work with are as follows:
AND
NOT
OR
XOR
ON/OFF Gate
ON/OFF Latch
1:2 Selector
Toggle
Most of these are self explanatory already, but just in case they aren't, please consult the above link to get the specific Block Reference (My Rep. currently prevents me from linking each of the above elements).
I'm thinking that I'm going to have success with using a series of Toggles and Gates, but I haven't quite been able to interconnect them properly to consistently behave in a perfect loop of invocation.
Bonus Points if you're really feeling up to it (you'll get an accepted answer for satisfying only the primary question, promise!):
Not only a linear On/Off per LED, but a complete permutation of all On/Off combinations;
All Off
Red On Blue Off Green Off
Red On Blue On Green Off
Red On Blue Off Green On
Red On Blue On Green On
Red Off Blue On Green Off
etc.
[edit]
If anyone with suitable rep could create/add the "ControllerMate" tag to this question I'd sure appreciate it.

I figured it all out, it was quite a long time coming. Let's break it into a few different topics;
(1) Keybinding / Key Representation
(2) Blocks Used
(3) Logic
First, I set up a simple key remap, but that example failed because pressing the Speedpad 02 key, would input it's original mapping (q) and the re-map I defined (w). I started crawling over the ControllerMate Forums, and I stumbled on a
great couple of posts, which would make better starting points than the .cmate definition files that are easy to find, but I digress…
After ripping my hair out looking for a setting I had missed, program preferences, or what have you, I looked on the forums and came across a great thread. After reading it, I took the 30 second and disabled all the buttons for the "keyboard" palette portion and the "mouse" palette portion that didn't actually exist.
This means disabling all but the 15 numbered keys, plus the orange key, plus the dpad for the keyboard portion, and disabling all the mouse keys for the mouse portion. I'm going to send this new map file to Ken (the ControllerMate developer).
After doing this, and naming the keys something sane so they're properly represented as the key they're labeled, the remaps work as expected. Speedpad 02 only enter my remaped key of w, and nothing else!
This first step finally was finished.
Second and third, I sat down and figured out a creative solution to the LED task;
I'm using exactly zero of the logic blocks above. I use meta blocks (Key blocks, group blocks) and math.
When pressing the Orange thumb button, a "accumulator" block runs, from 0 to 3, stepping by 1 each push.
That accumulator has 3 outlets, each going to a subtraction block. The first subtraction block subtracts 1, the second subtracts 2, the third subtracts 3.
All of those subtractor blocks connect directly to a "Value Selector". If the value is zero, that particular selector turns on.
Thus, when I've pushed the orange button once, the accumulator provides a value of 1, which goes to all of the subtractors, but more specifically the one controlling the Red LED subtracts 1, and totals 0, so it's Value Selector enables, which enables the "Num Lock" (Red
LED) light.
The LED Outlets connect to a constant number value block (again, the -1 subtraction stack connection ultimately provides a constant value of 1, the -2 subtraction stack ends up at a constant value of 2, -3 goes to 3.
All three of these constant value blocks goes to a series of 4 Addition blocks, Red LED/Constant 1 has four outputs, to all four Addition blocks. Blue LED/Constant 2 has four outputs that go to all four Addition blocks, and Green LED/Constant 3 [...].
Then, a configuration page can be placed on the canvas, in which case I moved the "remap" page onto the canvas, and attached it to an addition->expect 0 value selector block, meaning that if the addition equals zero, that particular value selector is on. When all LEDs are
off, the top half constant value blocks are disabled, and don't provide their particular value.
Now, I just need to figure out what to bind to the other three modes I was so desperately working on.
Picture of the ControllerMate Canvas;
http://vxjasonxv.com/images/ControllerMateSC2.png

Related

NEXSYS A7 Board - I2S2 PMOD

I'm working on a guitar effects "pedal" using the NEXSYS A7 Board.
For this purpose, I've purchased the I2S2 PMOD and successfully got it up and running using the example code provided by Digilent.
Currently, the design is a "pass-through", meaning that audio comes into the FPGA and immediately out.
I'm wondering what would be the correct way to store the data, make some DSP on this data to create the effects, and then transmit the modified data back to the I2S2 PMOD.
Maybe it's unnecessary to store the data?
maybe I can pass it through an RTL block that's responsible for applying the effect and then simply transmit the modified data out?
Collated from comments and extended.
For a live performance pedal you don't want to store much data; usually 10s of ms or less. Start with something simple : store 50 or 100ms of data in a ring (read old data, store new data, inc address modulo memory size). Output = Newdata = ( incoming sample * 0.n + olddata * (1 - 0.n)) for variable n. Very crude reverb or echo.
Yes, ring = ring buffer FIFO. And you'll see my description is a very crude implementation of a ring buffer FIFO.
Now extend it to separate read and write pointers. Now read and write at different, harmonically related rates ... you have a pitch changer. With glitches when the pointers cross.
Think of ways to hide the glitches, and soon you'll be able to make the crappy noises Autotune adds to most all modern music from that bloody Cher song onwards. (This takes serious DSP : something called interpolating filters is probably the simplest way. Live with the glitches for now)
btw if I'm interested in a distortion effect, can it be accomplished by simply multiplying the incoming data by a constant?
Multiplying by a constant is ... gain.
Multiplying a signal by itself is squaring it ... aka second harmonic distortion or 2HD (which produces components on the octave of each tone in the input).
Multiplying a signal by the 2HD is cubing it ... aka 3HD, producing components a perfect fifth above the octave.
Multiplying the 2HD by the 2HD is the fourth power ... aka 4HD, producing components 2 octaves higher, or a perfect fourth above that fifth.
Multiply the 4HD by the signal to produce 5HD ... and so on to probably the 7th. Also note that these components will decrease dramatically in level; you probably want to add gain beyond 2HD, multiply by 4 (= shift left 2 bits) as a starting point, and increase or decrease as desired.
Now multiply each of these by a variable gain and mix them (mixing is simple addition) to add as many distortion components you want as loud as you want ... don't forget to add in the original signal!
There are other approaches to adding distortion. Try simply saturating all signals above 0.25 to 0.25, and all signals below -0.25 to -0.25, aka clipping. Sounds nasty but mix a bit of this into the above, for a buzz.
Learn how to make white noise (pseudo-random number, usually from a LFSR).
Multiply this by the input signal, and mix or match with the above, for some fuzz.
Learn digital filtering (low pass, high pass, band pass for EQ), and how to control filters with noise or the input signal, the world of sound is open to you.

Can I 'poison' a value in VHDL

I'd like to be able to poison a signal in VHDL so that any subsequent consumers of it get a poisoned value too so I can find unintended links. Its fine if poisoning works in simulation only.
Background: I've made a CPU in VHDL and want to pipeline it. Before I do that I want to make sure that no part of the pipeline is sampling outputs from other parts when it shouldn't. So all the parts in the pipeline create and hold their valid output for exactly one clock cycle and set the various outputs to zero at other times. And for those times where the output is zero the next stage in the pipeline shouldn't even be looking at those values. But I want to confirm it under simlation.
So I tried setting the outputs to 'U' or 'X' during the times they dont represent data and these show up in the simulator as orange or red, but if I force them to be erroneously sampled the bad values dont propagate. So it seems like neither U nor X are what I want. Without changing the consumers of these (e.g. calling is_x(..) in hundreds of places) is there any easy way to poison those values when running under the simulator.
If it matters, this is on a Spartan7 based Arty board with the free version of Vivado.

How to decrease motion times in vim, specifically decreasing key depress reaction time?

I'm wondering how to navigate vim more quickly within paragraphs. It seems ( ) are not as efficient as just holding down E/W/B if it is a very small paragraph because of the tendency to overshoot your intended location, which I still do, thus I end up doing something like EEEEEEE/BBBB/EE/B to get to the intended spot. On a related note, how can you make it so that when you hold down a motion key in vim, the motion will begin being implemented faster?
Vim offers a lot of ways to make your cursor movement more efficient. A few of them include:
f<character>  Jump to the next occurrence of "<character>"
gj or gk Treat a wrapped line as multiple lines
<number>b or <number>w Move <number> words
0 Jump to column 0

Interview Q: Detecting a fighting game moveset

I got this as an interview question and I'm wondering what the optimal way of designing this system would be. The problem:
Say you have a fighting game where certain button combinations represent a special move. Implement 2 functions register_move([button combo],movename) which takes in a list of button inputs and a movename string and on_keypress(button) which registers the current keypress and prints a movename if a button combo has been activated. The buttons are represented as characters: 'U','D','L','R','A','B'
Example:
register_move(['A','B','U'],"Uppercut")
on_keypress('A')
on_keypress('B')
on_keypress('U') -> print "Uppercut"
you can assume moves are registered before on_keypress so you don't have to retroactively look back at the previous keypresses. You can use any language you like
Build a Deterministic Finite State Automaton. The initial state is "no keys recognised". On each keypress, transition into a new state; if it is a final state you have a move. All undefined transitions transition into the starting state. For your example,
S --(a)--> A
A --(b)--> AB
AB --(u) --> ABU: process "Uppercut", move to S
X --(x)--> S
where X is any state, x is any input not otherwise covered by the rules.
More practically and less theoretically, you will end up with a trie, so using a trie library should be sufficient. Root is "no input", walk it until a leaf, or restart on a mispress.
Considering the limited number of moves, you don't need a super efficient finite state machine to handle this.
You could simply store the strings in register_move, and have on_keypress memorize the last potentially valid sequence.
If the current key sequence is the prefix of at least one move (for instance "AB" being a prefix of "ABU"), you're done (just wait for the next keypress to see if a combo is reached).
If the sequence is no prefix, reset the sequence to the last keypress (for instance "ABD" -> "D"). This clears previous keypresses that correspond to no moves.
If the sequence corresponds to a move, perform the move (well, print it at least) and reset the sequence.
This would require to do a prefix search on every possible move combo, which is very quick if you have only a dozen or so. If for some reason you want to be quicker, you can indeed turn your list of combos into a prefix tree, but it would require a lot more code for little gain.

Application of Barrel Shifter

I am doing a VLSI Project and I am implementing a Barrel Shifter using a tool called DSCH.The schematic for the same is realized using Transmission Gates.
What the circuit does is, it ROTATES the 8 bit word(8-bit shifter) with as many rotations chosen from a decoder in one clock cycle.
But I want to know the use of a rotator and why is it still called a shifter even though it's rotating.
Also please help me with some applications regarding Rotator which could be added to the present circuit to show it's use?
Rotation is just shifting with the bit exiting from one end fed back into the input at the other end, possibly by way of the carry flag bit. At the level of a simple implementation, it would make sense to have one circuit for both operations, with some additional control lines to select the source at the input side between the output of the other side, 0, or 1. Sign extension during right shift of 2's complement numbers would be another selectable option often built in.
The stackexchange sites aren't really suited to "list" questions including about applications, but a couple come to mind:
If you want a vector to test every bit of another value in turn, and to do so repeatedly, you could just keep rotating an initial one-bit-active value over an over, never having to re-initialize it.
You could swap a two-part (typically double-byte) value to imitate the opposite endieness of encoding by rotating it half way. Or putting it another way, it can be a single-operation swap of the values of two pairable but also independently accessible registers (think AL and AH together making up AX in real mode x86). But this will not work two endian swap a four-part value, such as a 32-bit value on a byte-addressable machine.
Various coding, checksum, and hashing schemes may wish to transform a value

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