Audio processing - where would I start in terms of books and learning - objective-c

I've only just started learning Objective-C but am interested in audio processing and editing software and would like to know where to find information on where to start.
It's early days yet so I'm just looking for inspiration.

book: 'The Computer Music Tutorial' by Curtis Roads.
is a very good place to start.

You need signal processing background. So a discrete-time signal processing book such as oppenheim will do.
It's not going to be a walk in the park if you aren't good at math.

Related

Why should one learn register level programing for embedded systems, when options like Arduino IDE ,etc are available?

I have done projects using Arduino IDE.I have seen that many projects can be easily implemented using the IDE.Then, why should one learn register level programing? How important is it?
Can you do EVERYTHING with the Arduino library? If your project would need tight timing (for example to control a huge industrial apparatus), at the level of microsecond fractions, would Arduino still be a good choice? How about medical devices? How about performance - would you be able to design a BLDC controller using Vector Control in Arduino? How about battery life - would you be able to design a device that would run with a single CR2032 cell for a few years using Arduino? How about doing a network router? Does Arduino support threads?
Your question is like one of these:
who needs x-bit microcontrollers when we have y-bit microcontrollers at the same price?
who needs x programming language when we have y programming language?
who needs analog solutions when we have digital solutions?
who needs microcontrollers when we have microprocessors?
...
To be honest, personally (I write firmware for embedded devices),I see Arduino as a toy, nothing more.
Learning register level programming will help you learning how to read a datasheet, and also understanding how stuff works. It will give you more flexibility after you get the hang of it, plus you can optimize your code and write your own libraries.
By knowing how to read a datasheet it will be easier for you to develop device drivers and process algorithms.
What would you do if you cannot find an Arduino library for a certain sensor? If you were using register level programming, you could easily write your driver, by already knowing how to interpret the technical files ;).
Try it out, you will forget Arduino in the first weeks!
Best regards,
Alex Tofan

iPhone4, iOS5 Networked, multiplayer Augmented reality (AR/VR) game. Where to start?

I'm working on a pretty complicated app right now, but I just got a really good, niche market idea for an AR game for iPhone. I would love to get some preliminary research done on whether or not it is worth the effort. I got a few (about 4 days) in which to code this. Is this a realistic timeline for what I'm trying to accomplish?
While I'm pretty familiar with the CMDeviceMotion, and can get location updates from GPS, there are 4 features that I think may take a colossal amount of work:
1) Working with camera in real time to draw augmented reality controls. Are there any good tutorials on how to overlay a view on top of a live camera feed?
2)Making the app work when GPS reception is spotty. It seems that some apps know how to keep updating the location based on accelerometer/gyroscope from the last known location. Where would I start on this front?
3)The networking component. I'm very new to multiplayer games. I got a website that can run PHP. Should I abandon my networking idea until I get a web server? Or is there some way I can run this in P2P over 3G without a base station?
4)Google maps integration for fast updates. Does this take a lot of effort?
I'm sorry if any of these questions are too broad and vague. I'm very excited about this idea, but would like to know what I'm dealing with before spending time on the app and realizing that I'm dealing with a monumental task!
I think you are dealing with a monumental task (especially the multiplayer part, where you'll encounter issues like lag/timing).
For the augmented reality part of your project, you can take a look at mixare augmented reality engine. It's free and open source software and the code is available on github: https://github.com/mixare/
Be aware that if you base your code upon mixare, you'll have to release your app under the same GPLv3 license as mixare.
Good luck for your project!
HTH,
Daniele

Per-Process Network Monitor in Obj-C?

I want to write a program that monitors packets in and packets out, or in other words, network statistics. Is there any useful class in cocoa? I know there are some existed tools, but it will be a sub-routine of my program. So I must implement on my own.
Thanks a lot!
P.S. I only want to calculate one program / process 's statistics rather than the whole system.
You won't find much in Cocoa, you'll probably have to delve deeper into Core stuff. In the recently released pool of WWDC videos, they have a video on Core OS Networking that covers the Mac and iPhone platforms both, and gives a pretty good overview of some of the classes you might be needing to look at.
Might not hurt to give the Core Networking stuff a glance, since whatever you're monitoring is most likely using it:
http://developer.apple.com/mac/library/documentation/Networking/Conceptual/CFNetwork/Introduction/Introduction.html

What are some ideas for an embedded and/or robotics project?

I'd like to start messing around programming and building something with an Arduino board, but I can't think of any great ideas on what to build. Do you have any suggestions?
I show kids, who have never programmed, or done any electronics before, to make a simple 'Phototrope', a light sensitive robot, in about a day. It costs under £30 (GBP) including Arduino, electronics and off-the-shelf mechanics. If folks really get into mobile robots, the initial project can grow and grow (which I feel is part of the fun).
There are international robot competitions which require relatively simple mechanics to get started, e.g. in the UK http://www.tic.ac.uk/micromouse/toh.asp
Ultimate performance require specially built machines (for lightness) , but folks would get creditable results with an Arduino Nano, the right electronics, and a couple of good motors.
A line following robot is the classic mobile robot project. The track can be as simple as electrical tape. Pololu have some fun videos about their near-Arduino 3PI robot. The sensors are about £1, and there are a bunch of simple motor+gearbox kits from lots of places for under £10. Add a few £ for motor control, and you have autonomous robot mechanics, in need of programming! Add an Infrared Remote receiver (about £1), and you can drive it around using your TV remote. Add a small solar cell, use an Arduino analogue input to measure voltage, and it can find the sun. With a bit more electronics, it can 'feed' itself. And so it gets more sophisticated. Each step might be no more than a few hours to a few days effort, and you'll find new problems to solve and learn from.
IMHO, the most interesting (low-cost) competitions are maze solving robots. The international competition rule require the robot to explore a walled maze, usually using Infrared sensors, and calculate their optimal route. The challenges include keeping track of current position to near-millimeter accuracy, dealing with real world's unpredictably noisy environment and optimising straight-line speed with shortest distance cornering.
All that in 16K of program, and 1K RAM, with real-time interrupt handling (as much as 100K interrupts/second for some motor systems), sensor sampling, motor speed control, and maze solving is an interesting programming challenge. (You might make it 'easy' with 32K of program, and 2K RAM :-)
I'm working on a 'constrained' robot challenge (based on Arduino) so that robot performance is mainly about programming rather than having a big budget.
Start small and build up to something more complex. Control servos. Blink LEDs. Debounce inputs. Read analog sensors. Display text on an LCD. Then put it together.
Despite the name, I like the "Evil Genius" book for PIC microcontrollers because of the small, easily digestible projects that tend to build on one another. It is, of course, aimed at PIC programmers rather than the Arduino, but the material covered will be useful no matter what you're developing on.
I know Arduino is trendy right now, but I also like the Teensy++ development board because of its low price-point ($24), breadboard-compatible PCB, relatively high pin count, Linux development environment, USB connectivity, and not needing a programmer. Worth considering for smaller projects.
If you come up with something cool, let me know. I need an excuse to do something fun :)
Bicycle-related ideas:
theft alarm (perhaps with radio link to a base station which is connected to a PC by Ethernet)
fancy trip computer (with reed switch or opto sensor on wheel)
integrate with a GPS telematics unit (trip logging) with Ethernet/USB download of logged data to PC. Also has an interesting PC programming component--integrate with Google Maps.
Other ideas:
Clock with automatic time sync from:
GPS receiver
FM radio signal with embedded RDS data with CT code
Digital radio (DAB+)
Mobile phone tower (would it require a subscription and SIM card for this receive-only operation?)
NTP server via:
Ethernet
WiFi
ZigBee (with a ZigBee coordinator that gets its time from e.g. Ethernet or GPS)
Mains electricity smart meter via ZigBee (I'm interested now that smart meters are being introduced in Victoria, Australia; not sure if the smart meters broadcast the time info though, and whether it requires authentication)
Metronome
Instrument tuner
This reverse-geocache puzzle box was an awesome Arduino project. You could take this to the next step, e.g. have a reverse-geocache box that gives out a clue only at a specific location, and then using physical clues found at that location coupled with the next clue from the box, determine where to go for the next step.
You could do one of the firefighting robot competitions. We built a robot in university for my bachelor's final project, but didn't have time to enter the competition. Plus the robot needed some polish anyway... :)
Video here.
Mind you, this was done with a Motorola HC12 and a C compiler, and most components outside the microcontroller board were made from scratch, so it took longer than it should. Should be much easier with prefab components.
Path finding/obstacle navigation is typically a good project to start with. If you want something practical, take a look at how iRobot vacuums the floor and come up with a better scheme.
Depends on your background and if you want practical or cool. On the practical side, a remote control could be a simple starting point. It's got buttons and lights but isn't too demanding.
For a cool project maybe a Simon-style memory game or anything with lights & noises (thinking theremin-style).
I don't have suggestions or perhaps something like a line follower robot. I could help you with some links for inspiration
Arduino tutorials
Top 40 Arduino Projects of the Web
20 Unbelievable Arduino Projects
I'm currently developing plans to automate my 30 year old model train layout.
A POV device could be fun to build (just google for POV Arduino). POV means persistence of vision.

How can I make my own microcontroller?

How can I make my own microcontroller? I've done some work using GAL chips and programmed a chip to do simple commands such as add, load, move, xor, and output, but I'd like to do something more like a real microcontroller.
How can I go about doing this? I've read a little bit about FPGA and CPLD, but not very much, and so was looking for some advice on what to get and how to start developing on it.
Look here for a good wiki book. I had some coursework I wrote when I was teaching Electronic Eng, but I couldn't find it around. When I was teaching, most of the students were happy to use the schematic capture tools in the Xilinx Foundation package. They've moved onto ISE and WebPACK now. You can download the WebPack for free, which is useful, and it has schematic capture and simulation in it.
If you really want to shine, learn VHDL or Verilog (VHDL seems to be more common where I've worked, but that is only a small smattering of places) and code the design rather than enter it through the GUI.
If you know ANYTHING at all about digital logic design (and some HDL) I rekon you can have a somewhat functional 8-bit microprocessor simulating in VHDL in about 2 days. You're not going to build anything blazingly fast or enormously powerful in that time but it's a good starting point to grow from. If you have to learn about digital design, factor in a couple of days to learn how the tools work and simulate some basic logic circuits before moving onto the uP design.
Start learning the basics of digital systems, and how to build a binary adder. Move on to building an ALU to handle addition, subtraction, and, or, xor, etc and then a sequencer to read opcodes from RAM and supply them to the execution unit.
You can get fancy with instruction set design, but I'd recommend starting out REALLY simple until you have your head around whats going on, then throw it out and start again with something more complex.
Once you have the design simulating nicely you can gauge its complexity and purchase a device to suit. You should look at a development system for the device family you've chosen. Pick a device bigger than what you need for development because it's nice to be able to add extra instrumentation to debug it when it's running, and you almost certainly won't have optimized your design in the early stages of getting it on the device.
EDIT: Colin Mackenzie has a good tutorial about uC design and some FPGA boards as well as a bit of other stuff.
You may want to have a look around OpenCores.org, a "forge" site for open source IP core development. Also, consider getting yourself a development board like one of these to play around with.
Much of the tools ecosystem revolves around VHDL, although Avalda is working on tools to compile F# for FPGAs.
I saw a textbook once that stepped through building a machine from TTL chips. This had the same instruction set as a PDP-8, which is very - and I mean very - simple, so the actual machine architecture is easy to implement in this way.
The PDP-8 FAQ mentions a book: "The Art of Digital Design," second edition, by Franklin Prosser and David Winkel (Prentice-Hall, 1987, ISBN 0-13-046780-4). It also mentions people implementing it in FPGA's.
Given the extreme simplicity of this CPU architecture and availability of PDP-8 code or reference implementations it might be a good starting point to warm up with.
Alternatively, an acquaintance of mine implemented a thumb (cut down ARM) on a FPGA as a university project run by one Steve Furber (a prominent Acorn alumnus). Given that this could be compressed into a format small enough for a university project it might also be a good start.
To play with soft-core microprocessors, I like the Spartan 3 Starter Board from Digilent just because it has 1M of static RAM. SDRAM and DDR RAM are harder to get going, you know.
The leds, switches and a simple serial interface are a plus to debug and communicate.
As someone already pointed out, OpenCores.org is a good place to find working examples. I used the Plasma uC to write some papers while on university.
A microcontroller can be as simple as a ROM (instruction*2^x + (clock phase) is the address, outputs are the control signals, and you're good to go). Or it can be a complex harry beast with three arms and branch prediction support hardware.
Can you give more details about your aspirations?
After searching some very helpful links by all of you, I came across this Wikiversity course.
One of the first sentences is, "Have you ever thought to build your own microprocessor?"
Xilinx has a MicroBlaze and a PicoBlaze soft controller for its FPGAs. The latter is free, while, IIRC, the Microblaze is to be paid for.
As its name suggests the PicoBlaze is a small processor, which has its limitations, but OTOH is compact enough to run on a CPLD. Anyway a nice processor to get you started.
Pablo Bleyer has a PicoBlaze-compatible PacoBlaze. PacoBlaze was written in Verilog (which, like Adam said, less common than VHDL).
You need a big fpga for a little mcu.
You need a fpga with the correct hardware blocks if you need things like AD.
You need a soft core to put into the fpga.
But how about to just play around with a normal MCU before this project,
so you kind of know where you are going? How about some AVR:s from Atmel.
You can get free samples of pic micro controllers at this site. Last I knew, you don't even have to pay shipping.
http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=64