1. SM3121 Hardware Technology Mark Green School of Creative Media

2. Introduction  Start by looking at some of the technology involved  Not very technical, enough to give an idea of what’s possible  Need to know the limitations, why things are done a particular way

3. Microprocessors  Need to have some type of computer, this is the heart  All computers have microprocessors, so what’s the difference here??  In computers microprocessor use lots of power, they produce lots of heat, they need fans that make lots of noise  Picture this in your mobile phone!

4. Microprocessors  Mobile phones, PDA, etc don’t plug into the wall, they are mobile, they use batteries  Power is very limited, want devices to run for many hours, at least a day  Processors must use very little power, if device isn’t being used it should be almost nothing, but still want instant response

5. Microprocessors  These devices are small  Can’t generate a lot of heat, can’t have a fan (won’t work with mobile phone)  Don’t want to hold something that is over 50C  Microprocessor should run cool, doesn’t need fan or cooling  This goes well with low power

6. Microprocessors  Size is also important, mobile phones need to be small  Need to have memory, don’t want a separate chip for this, combined with microprocessor  Often combine other functions that are separate chips in a PC

7. Microprocessors  So we aren’t going to use a 3Ghz Pentium 4 processor, but what are we going to use?  There are several chip families that have been developed for low power mobile applications  Intel and Motorola have popular lines, there are also several smaller manufacturers

8. Microprocessors  Cost is also very important  Pentium 4 chips cost more than most mobile phones  We need to keep costs low, implications: Not as fast as PCs Not as fast as PCs Not as many features as PCs Not as many features as PCs Combine the functions of several chips onto one chip Combine the functions of several chips onto one chip

9. Microcontrollers  A microcontroller is a single chip computer, it usually has: Processor Processor ROM memory ROM memory RAM memory RAM memory Digital input and output Digital input and output Analogue input and output Analogue input and output Communications to host Communications to host

10. Microcontrollers

11. Microcontrollers  Basically have everything required to run a dedicated application, not a general purpose processor  Used in: Toys Toys Cars Cars Appliances Appliances MP3 players MP3 players Mobile phones Mobile phones

12. Microcontrollers  Processors are not fast, optimized for low power  Can have as little as 128 bytes of memory, but some have a lot more (1 Mbyte)  Usually have serial or USB connection to host, but some use ethernet  Programmed in assembler, basic or C, programs are usually quite short

13. Memory  Many types of memory are used in toys and gadgets, depends on the product  RAM: this is what we are used to on PCs, memory that we can read and write  ROM: read only memory, most of the software is in ROM, don’t have a disk so we need to get the software from somewhere, ROM is the standard way

14. Memory  Problem with ROM: written once when the chip is made, we can’t change it  Different from PC, easy to change software, easy to add more software  With ROM we are stuck with what we got  Can put programs in RAM, but they will be lost when the batteries run out or are changed

15. Memory  To develop applications we need memory we can write, and that will stay there  This is a common problem, so there are several solutions  EPROM: electrically programmable ROM, use special hardware to write contents of memory (not very expensive)  Some can be erased and rewritten (EEPROM)

16. Memory  Flash memory: a better solution, can be written many times (around 1 million) and holds its data  Available in a range of sizes, common sizes are 64, 128 and 256 Mbyte  One problem is that there are too many different standards: CF, SD, MM, etc, 5 or 6 major standards

17. Memory  Flash memory solves our application development problem, can be used with a range of devices: Mobile phone Mobile phone PDA PDA Gameboy Gameboy  Write the flash memory, insert it into device and you are ready to go

18. Sensors  Recall the difference between analogue and digital: Digital: on or off, 0 or 1, this is what a computer understands, combine bits to produce bytes, etc Digital: on or off, 0 or 1, this is what a computer understands, combine bits to produce bytes, etc Analogue: real continuous values, what we find in the real world, temperature, pressure, speed, cannot be understood by a computer Analogue: real continuous values, what we find in the real world, temperature, pressure, speed, cannot be understood by a computer

19. Sensors  Most microcontrollers have both digital and analogue I/O  Digital input can be used for simple sensors: Switch is open or closed Switch is open or closed Simple light detectors Simple light detectors  Digital output can be used as a switch, turns lights on, control devices, even run motors

20. Sensors  Digital I/O is typically 1 bit, simple on or off  Analogue gets more complex, need a way of converting between digital and analogue worlds  A/D – analogue to digital converter, converts an analogue signal into a digital value, many ways of doing this, will only look at the very basics

21. Sensors  Bits per sample, precision of the value, most basic is 8 bits, analogue signal converted to a value from -128 to 127  12 bit A/D converters are also common, but more expensive  For simple signals like light intensity, temperature, speed 8 or 12 bits is good enough, for sound need 16 bits

22. Sensors  Usually have more than one analogue input, but A/Ds are expensive, don’t want to have one for each input  Light level, temperature, speed don’t change very quickly, only need to sample a few times per second  Can share the A/D converter, can have multiple channels (usually 8) select channel and read the value

23. Sensors  D/A: digital to analogue converter  Usually 8 to 12 bits  Usually 1 or 2 per microcontroller  Can’t use channels, need to send a continuous analogue value to device, such as a motor or light

24. Sensors  What can we sense?  Depends upon your imagination and money  Easy things are light level, temperature, pressure, touch, can get relatively cheap sensors for these, $25HK range  Can also measure distance, range of devices for this, can be quite expensive

25. Sensors  Some consider cameras to be the ultimate sensor, can see everything in the environment  Problems: Expensive compared to other sensors Expensive compared to other sensors Require a lot of processor power, we don’t have this Require a lot of processor power, we don’t have this Hard to program Hard to program

26. Actuators  Cause something to happen, our output devices  Could be as simple as a light  Digital output can be used as a switch, turn a light on or off  Typically low voltage off of a microcontroller, need to save power  Can use a relay to switch larger voltages

27. Actuators  Motors are common actuators  Several ways to control them  Simple motors use an analogue signal, speed controlled by voltage  Cheap and easy, but not very accurate  Can control direction and to some extent the speed, but cannot accurately determine how far it will go

28. Actuators  Stepper motors give us much more control, but at a price  Motor rotates a fixed amount each time it gets a pulse, usually quite accurate  The faster the pulses, the faster the motor spins, so we have some control over its speed  Counting pulses tells us how far we have gone

29. Displays  No 17” LCD monitor or CRT, way too big and requires too much power  Many devices don’t have displays, but they are common on mobile phones and PDAs  Display must be low power, or it will drain the battery  Also needs to be small and visible in bright environments

30. Displays  LCD displays require very little power, the most common form of display for small devices  The LCD itself doesn’t require much power, but its hard to see on its own  Some devices just use the LCD, like some Gameboy models, but for most people this isn’t good enough

31. Displays  Usually have a light behind the LCD, makes it much easier to see  Common on mobile phones and PDAs  Problem, the light requires much more power than the LCD  Only use light when user is interacting with device, turn it off quickly  Assume user can read display is a minute or two

32. Displays  Early LCD displays were black and white  Colour introduced in last few years, common to have 12 bits or 16 bits of colour  Since devices are small, displays must also be small, typically only a few inches  This limits the resolution of the displays, must be able to read them

33. Displays  PDAs have 320x240 displays, can go higher but may not be worth it  Higher resolution means smaller pixels, characters will be smaller, too hard to read  Mobile phones are harder, displays are usually smaller, want phones to be small  Need to be able to read while walking, need to have larger text

34. Case Studies  Look at some typical devices to see how this all fits together  Introduce some of the terms that we will use later  Unlike PCs, there is not a lot of technical information on these devices  Consumer devices, don’t need to provide information to programmers, etc

35. Arm Processor  One of the most popular processor families for mobile devices  Processor design licensed to other companies (Intel, Samsung, Fujitsu, etc), also produce custom designs for devices  For details see http://www.arm.com http://www.arm.com  Found in everything from phones, PDAs and GameBoys

36. Arm Processor  Wide range of processors: ARM ARM 16/32 bit16/32 bit Low power, low speed, smallLow power, low speed, small StrongARM StrongARM 32 bit32 bit Medium speed, low powerMedium speed, low power XScale XScale 32 bit32 bit High end, expensive, medium powerHigh end, expensive, medium power

37. Mobile Phones  Wide range of architectures, usually include: Processor Processor Memory Memory Phone network interface Phone network interface Display Display Keypad Keypad  Little technical information, tends to change rapidly

38. Nokia Series 60  Nokia has several phone series, vary on price and features  Series 60 is for high end phone, including N-Gage  Symbian OS, Supports applications in: C/C++ C/C++ Java Java HTML, SMIL, MMS, etc HTML, SMIL, MMS, etc

39. Nokia Series 60  Latest phone is the 6600: ARM (StrongARM?) 100 MHz (?) processor ARM (StrongARM?) 100 MHz (?) processor 176x208 display, 16 bit colour 176x208 display, 16 bit colour 6 Mbyte memory 6 Mbyte memory Flash memory slot Flash memory slot Bluetooth, infrared connectivity Bluetooth, infrared connectivity Can sync with PC Can sync with PC

40. Mobile Phones  Most modern mobile phones have some type of web browser, several standards for this  SMS is standard, MMS is becoming more popular  Java is becoming standard on medium to high end phones  Small amount of memory, usually around 1 MByte

41. PDA  Two basic families of PDAs: Palm Palm Windows CE Windows CE  There are a few other types, but they aren’t very popular  Two families address two market areas with little overlap  Will mainly look at Windows CE

42. Palm  Palm aims at low end of market, cheapest devices are Palm based  Can run on very limited hardware  Viewed as an appliance, replace notepads, calendars, meeting schedules  Not particularly friendly to developers, viewed more as a closed system  Not very expandable

43. Windows CE  Aimed at more high end devices  Needs more hardware than Palm  Viewed as a miniature version of office PC  Take your office with you  Friendly to developers (free development tools), similar to Windows on PC  Easy to expand, add new features

44. iPAQ  Popular PDA developed by Compaq before they were bought by HP  Line continued by HP  One of the best Windows CE devices  Range of devices available, vary on processor speed, memory, features  Price range $2000 - $5000 HK

45. iPAQ  Basic hardware features StrongARM / XScale processor, range from 200 to 400 MHz StrongARM / XScale processor, range from 200 to 400 MHz 64 MByte RAM, 32 MByte ROM 64 MByte RAM, 32 MByte ROM 240 x 320 display, 16 bit colour 240 x 320 display, 16 bit colour Flash memory card Flash memory card Bluetooth, infrared connectivity (not all models) Bluetooth, infrared connectivity (not all models) Can sync with PC Can sync with PC

46. PDA  iPAQ is the high end, most other PDAs have lower performance, fewer features  Typical processor speeds are in the 200Mhz range  Most have 32Mbyte or less memory, Palm devices tend to have less  Not all have good connectivity, maybe just serial or USB

47. GameBoy  There have been many versions of this device over the years  One of the most successful mobile devices  Look at the GBA, the most recent version of the device  These are cheap devices, from $500 to $1500 HK, depending upon the version and packaging

48. GameBoy  The hardware ARM7TDMI processor at 16.78 MHz ARM7TDMI processor at 16.78 MHz 32 Kbytes of internal RAM, 256 Kbytes of external RAM 32 Kbytes of internal RAM, 256 Kbytes of external RAM Up to 240x160 display with up to 15 bit colour Up to 240x160 display with up to 15 bit colour ROM cartridges or flash memory used for games, up to 32 Mbytes of data per game ROM cartridges or flash memory used for games, up to 32 Mbytes of data per game Serial connection for external communications Serial connection for external communications

49. GameBoy  There have been other mobile game devices, but this is the one that lasted  This is not a powerful platform  Hardware a bit of a hack, tries to be compatible with older versions  Can do independent development, but this is not supported by Nintendo

50. Note  If you are interested in console game development the GameBoy is a good place to start  Not as complicated as consoles, but a lot of the same techniques are used  Can get everything you need for under $1000HK, including the GameBoy!

51. Summary  Not near as powerful as a PC, but doesn’t have to do as much work  Small screens, need to think carefully about screen space  Development not as easy as PCs, can have emulators for PCs, but really need to get content onto device for testing  Need to have good communications for this

52. So What?  Why do I care about all of this?? I’m just going to produce web pages for mobile phones  Most web designers work on PCs, faster processors, special hardware for graphics and media  This hardware doesn’t exist on most mobile devices, applications could run much slower

53. So What?  About 10% of the raw processor power  No floating point -> slower media playback  No special multimedia instructions -> slower media playback  A web site with good performance on a PC may be unusable on a mobile phone or PDA  Must be careful in development

54. So What?  Large difference in mobile devices  Application may run on latest phone, but won’t run on older ones  Large number of phones are two or more years old  May not care about this, willing to let market grow as people replace their devices

55. Future  Rapidly evolving area, faster than PCs  Adding multimedia capabilities to mobile devices, special processor for video, images and sound  3D graphics hardware for mobile devices, OpenGL-ES  Similar performance / features to 1995 era PC graphics cards