1. See the Lab. 1 web-site and later lecture notes for more details
Over-view of Lab. 1
See the Lab. 1 web-site and later lecture notes for more details

2. NEW SLIDE
All embedded projects (every one built in the world) require the following
Build a “project” directory using a “development environment.
Add code to -- CODE IS RE-USED IN LATER LABS
Initialize the system
Read general purpose input signals
Write general purpose output signals
Initialize and use peripherals
Timers, serial interfaces to LCD screens, thermal sensors, light sensors, accelerometers, DSP programs for analysis
Build system in a controlled and testable manner
Incremental build, testing framework
Operating system (Super loop, co-operative scheduler, event driven scheduler)

3. E.g. Radio controlled voice activated robotic car “term” project
Set-up the processor to control the board A/D and D/A; allows capture and play-back sound.
Set-up the processor so that we can read general purpose input lines (GPIO -- switches) so we send various different commands.
Use the digital signal processing (DSP) part of Blackfin processor to run canned (meaning written by somebody else) frequency analysis program to recognize voice commands
Use the analysis of the sounds to output control values to a radio transmitter and control the car.

4. Main Code – pseudo code for the “voice controlled car”
main( ) { // red – means canned code – green means done in Lab. 1
Launch the Analog Devices audio “echo” program – a background interrupt-driven task that is given to you – you will modify this code
InitFlashASM( ); // Activate the system Flash memory without // stopping audio program which uses the Flash interface too
// This enables you to write to the LED’s on the Blackfin board
InitializePFInterfaceASM( ); // Activate the Push-button controller
// This enables you to read switches SW1, SW2, SW3, SW4
Launch “VDK multi-threads” (separate processes) to control various processes // The VDK O/S is provided as part of the VDSP IDE
Thread 1 – Store batches of sound for analysis
Thread 2 – Analyze previous stored sound for “commands”
Thread 3 – Use previous commands to send commands to control the car
Thread 4 – Check evaluation buttons for “options” (autopilot etc)
Thread 5 etc

5. Another possible example project using the same code ideas
We want to build a audio controller
Reuse CANNED examples provided by Analog Devices
Audio in captured using audio A/D (CODEC)
Audio out generated using audio D/A (CODEC)
Manipulate the sound quality
Modify functions that use Lab. 1 hardware interfaces
Push buttons to control audio controller operations – e.g. graphics equalizer
LED lights to display operation results and sound volume level (dancing lights)

6. Main Code – pseudo code for the “audio controller”
Launch the Analog Devices audio “echo” program – a background interrupt-driven task that is given to you – you will modify this code
InitFlashASM( ); // Activate the system Flash memory without stopping // the audio program which uses the Flash interface too
InitializePFInterfaceASM( ); // Activate the Push-button controller
Wait for button1 to be pressed and released (ReadButtonASM() ), then play the sound at half-volume.
Wait for button2 to be pressed and released, play the sound at normal volume
When button3 is pressed -- Generate the extremely fascinating (but completely useless) dancing lights which change with the audio stream volume level
Wait for button4 to be pressed and released, quit the program (turn off the sound and stop the processor) }

7. If we wanted to get fancy we could do the following to the audio Talkthrough program
Gargling operation
Need to add a simple counter that increments by 1 every 1 / s (increments each time that an audio sample is obtained)
Use the counter to control when to turn the sound off and on every ½ s
Gargling sound is produced rather than just “turning the sound off”
For more details – see Lab. 1 from 2006.

8. Lab. 1 – Key project interfacing Microcontroller I/O demonstration
MODIFIED SLIDE
Lab. 1 – Key project interfacing Microcontroller I/O demonstration
Your group must come into the laboratory class prepared to be able to demonstrate all of the following by the end of laboratoryperiod
You will make use of some of the code developed during the assignments. (Note assignments may be due AFTER the laboratory)
Initialize the push-button controller interface
Read, and use, a value provided by the push-button controller.
Initialize the Flash LED display interface (so that it works)
Write a value to the LED display
Read, and use, a value stored in the LED display, so you can test that you are getting the correct answer
Demonstrate tests to show that these operations work as required
OPTIONAL “ENCM511 Project club”
Each laboratory will provide you with enough interface information to get a component of the voice-activated radio control car to work.
Extra hours of work will needed to write and test the necessary C++ code to make the interfaces operate correctly – but that can be split amongst those interested.
Develop a voice activated “Windows Mobile cell-phone application”

9. Lab. Task – Does my ADSP-BF533 board work
Lab. Task – Does my ADSP-BF533 board work? Download audio-talk-through program
If you have not already done so, download and expand ENCM511Directory2009.zip file (used in assignment 1) so that you have the correct directory. structure and test driven development environment needed for Laboratory 1.
Download and expand the files in 09CPP_Talkthrough.zip into your AudioDemo directory.
Build an AudioDemo Blackfin project in your AudioDemo directory and add the (provided) files into the project -- compile and link.
Download the executable (.dxe) file onto the BF533 processor.
Hook up your CD or IPOD output to the CJ2 stereo input.
Hook up your ear-phones to the CJ3 stereo output.
Run the AudioDemo.dxe executable and check that the talk through program is working.
This task demonstrated your ability to build VDSP Blackfin projects and run the code. The AudioDemo code (running in a multithread environment) forms the basis of the (optional) voice-activate radio-controlled car project.

10. Tasks of Laboratory 1 MODIFIED SLIDE
Basic Task – develop the LED interface
Initialize the Flash memory using the Blackfin external bus interface unit (EBIU) (ASM)
Initialize the Flash memory controller of the Blackfin Evaluation Board LED’s (ASM)
The Blackfin external bus interface unit is used to perform many “microcontroller” operations
Initialize SDRAM, audio chips etc,
Task (mainly in C++) that use the LED interface
E.g. Develop a simple counter (in C++) and display value
E.g. Write a C++ routine to write morse code values into an array
E.g. Write a routine to transfer the morse code values to the LED’s (first in C++, then ASM)
homepage.ntlworld.com/dmitrismirnov/morse-tab1.JPG

11. Task – Initialize the Programmable flag interface – 16 GPIO lines on the Blackfin
Warning – could burn out the Blackfin processor if coding is done incorrectly
You need to set (store a known value to) a number of internal registers in the Blackfin processor core.
Other processors need equivalent GPIO control methods
Most important registers
FIO_DIR – Data DIRection – set to ?? for input ****
FIO_INEN – INterface Enable – set to ?? For enable
FIO_FLAG_D – Programmable FLAG Data register

12. Flag Direction register (FIO_DIR)
Why do you need to know how to do read (load) and write (store) on internal registers?
Flag Direction register (FIO_DIR)
Used to determine if the PF bit is to be used for input or output WARNING SMOKE POSSIBLE ISSUE
USE equivalent of AND instruction from ENCM369 to clear bits PF11 to PF8 to 0 for input, but must leave all other bits unchanged in value.
Read peripheral register value, use AND to change the required bits, write back value

13. Registers used to control PF pins
Flag Input Enable Register
Only activate the pins you want to use (saves power in telecommunications situation)
USE OR instruction from ENCM369 to enable (activate) pins PF11 to PF8 for input, leave all other bits in register unchanged
Read peripheral register value, use OR to change the required bits, write back value

14. Registers used to control PF pins
Flag Data register (FIO_FLAG_D)
Used to read the PF bits (1 or 0)
Need to read pins PF11 to PF8, ignore all other pins values. This requires AND and SHIFT instructions from ENCM369.
Read register value, use AND to mask unwanted bits, then use masked value in your code

15. Task – Setting up the programmable flag interface
MODIFIED SLIDE
Task – Setting up the programmable flag interface
Follow the instructions carefully
FIO_DIR – direction register – write 0’s to bits 8, 9, 10, 11 – leave other bits unchanged (READ / then AND / WRITE operations) -- This sets the pins as INPUT pins
FIO_INEN – input enable register – write 1’s to bits 8, 9, 10, 11 – leave other bits unchanged (READ / then OR / WRITE operations) – This activates (turns on) the pins as INPUT pins
Other GPIO registers write 0’s to bits 8, 9, 10, 11 – leave other bits unchanged (READ / then AND / WRITE operations)
There is a test program that will enable you to check your code – provide a screen dump of test result.

16. Task – Read the switches on the front panel in “real life”
MODIFIED SLIDE
Task – Read the switches on the front panel in “real life”
Transfer the information to the LEDs so you can demonstrate correct operations
Build Initialize_ProgrammableFlagsASM ( )
MUST HAVE 50 pin cable connected between logic board and Blackfin for the switch values to be read correctly – otherwise switch input always reads “1”. Watch the demonstrations
Logic board power supply must be turned on (or your code will always read 1 from the switches)
What we could do – “Simple optical transmitter project”
Place a “light sensitive detector” in front of the LEDs on a “second” Blackfin station where that station is sending morse messages.
Use the output of the detector as the input to the “First Blackfin” instead of the switch, and capture the light code signals
Print out the “morse” code transmissions on the screen of the “first” station – very basic optical transmission

17. extern “C” int ReadGPIOFlags( )
MODIFIED SLIDE
extern “C” int ReadGPIOFlags( )
#include <blackfin.h>
.global _ReadGPIOFlags;
_ReadGPIOFlags:
// Make an address register “point” to
// the GPIO Flag register to read switches
P1.L = lo (FIO_FLAG_D);
P1.H = hi (FIO_FLAG_D);
// Read the “16” bit flag register value and return // the value for the C++ code to use
R0 = W[P1] (Z); // convert 16 to 32 bits
_ReadGPIOFlags.END: RTS;
Must use W [ ] 16-bit read since the manual shows that FIO_FLAG_D register is 16-bits
ZERO EXTENSION Must use W[P1] (Z) zero-extend as this adds 16 zeros to the 16 bits from FIO_FLAG_D register to make 32-bits to place into R0
0xFF00 becomes 0x0000FF00

18. Sign extension of input often needed
NEW SLIDE
Sign extension of input often needed
FLAG REGISTER HOLD BIT-PATTERNS NOT NUMBERS
The audio chip brings in 24 bit values representing the digital value (positive or negative) of the audio volume Negative values 0x (-2^23) to 0xFFFFFF (-1)
Positive values 0x (0) to 0x7FFFFF (2^23 -1).
However, the values are read into the Blackfin 32 bit data register as values the audio volume (ZERO EXTENSION)
Positive values 0x (PLUS 2^23) to 0x00FFFFFF (PLUS 2^24 - 1)
Positive values 0x (0) to 0x00007FFFFF (2^23 -1)
Audio signal will sound very distorted unless sign extension applied
Negative values 0xFF (- 2^23) to 0xFFFFFFFF (- 1)
FLAG DATA REGISTER ZERO EXTENSION Must use W [ ] 16-bit read since the manual shows that FIO_FLAG_D register is 16-bits
Must use W[P1] (Z) zero-extend as this adds 16 zeros to the 16 bits from FIO_FLAG_D register to make 32-bits to place into R0
0xFF00 becomes 0x0000FF00

19. Using that assembly code from C++
extern “C” int ReadGPIOFlags( );
int ReadPushButtonSwitches(void) {
InitializeGPIORegisters( ); // Lab. 1
int GPIOFlagValues = ReadGPIOFlags( ); // Must happen AFTER Init( )
int maskToRemoveUnwantedBits = 0x0F00;
// Review of ENCM369 – AND operation & and NOT &&
int wantedGPIOFlagValues = GPIOFlagValues & maskToRemoveUnwantedBits;
return (wantedGPIOFlagValues >> 8); }
Returns 1 if switch 1 pressed, returns 2 if switch 2 pressed,
Returns 4 if switch 3 pressed, returns 8 if switch 4 pressed,
Returns 5 if switch 1 and switch 3 are pressed at the same time
SW SW SW SW1

20. Controlling a radio controlled car
A L F R
Switch 2 pressed means go forward for 1/ 2 s
Switch 1 means turn right
Switch 3 means turn left
Switch 4 means accept command
Thus pressing switches 2, 2, 1 with 2, 2, 2, 3 with 2, 2, 2, 0, 0, 0, 0
Would cause the car to go down an “S”

21. Store the commands to control a car
#define STOP 0 int storeCommands[20]; int numberStopCommands = 0; int count = 0; while (numberStopCommands < 4) { command = GetValidCommand( ); if (command == STOP) { numberStopCommands ++; } else { numberStopCommands = 0; storeCommands[count++] = command;

22. Get a valid command to control a car
#define SWITCH4 0x8 #define ACCEPTCOMMAND SWITCH4 int GetValidCommand( ) { int command = ReadPushButtonSwitches( ); while ( (command & ACCEPTCOMMAND) != ACCEPTCOMMAND} { command = ReadPushButtonSwitches( ); } // Get here when somebody pushes switch 4 // Explain why it is a logical error if we just exit this code here return command;

23. Task -- Tests
There needs to be software tests (E-TDD) to allow you to demonstrate that your code works correctly
Note there are test executables (.dxe) available to test out your equipment
This code can be used to test the switches and the LED interface on your board. SwitchToLED.dxe
This is the final version of my code for the “fancy” audio controller  DrSmithAudioController.dxe