Please edvice by objective-c code snippets and useful links of how can I control all audio signals of output in OS X?
I think it should be something like proxy layer somewhere in OS X logic layers.
Thank you!
It's somewhat sad that there is no simple API to do this. Luckily it isn't too hard, just verbose.
First, get the system output device:
UInt32 size;
AudioDeviceID outputDevice;
OSStatus result = AudioHardwareGetProperty(kAudioHardwarePropertyDefaultOuputDevice, &size, &outputDevice);
Then set the volume:
Float32 theVolume;
result = AudioDeviceSetProperty(theDevice, NULL, 0, /* master channel */ false, kAudioDevicePropertyVolumeScalar, sizeof(Float32), &theVolume);
Obviously I've omitted any error checking, which is a must.
Things can get a bit tricky because not all devices support channel 0 (the master channel). If this is the case with your device (it probably is) you have two options: query the device for its preferred stereo pair and set the volume on those channels individually, or just set the volume on channels 1 and 2.
Related
I am trying to record audio using a 12 bit resolution ADC, take the sample buffer and send it through CAN FD to another device, which takes samples of this audio and creates a .wav and plays it. The problem is that I see the data of the microphone being sent through CAN FD to the other device, but I am not able to transform this data into a .wav file properly and hear what I say through the microphone. I only hear beeps.
I'm creating a new .wav every 4 CAN FD messages in order to make some kind of real time communication and decrease the delay, but I don't think this is possible or if I am thinking it the proper way.
In this thread I take the message sent by the CAN FD and concatenate it in a buffer in order to introduce it in a .wav file. I have tried bigger buffers but it doesn't change the outcome.
How could I be able to take the data from the CAN FD and hear it?
Clarification: I know using CAN FD to transmit audio isn't the proper way, but it is for a master project.
struct canfd_frame frame;
CAN_MSG msg;
int trama_can[72];
int nbytes;
while (status_libreria == 0)
;
unsigned char buffer[256];
// FILE * fPtr;
int i=0,x=0;
//fPtr = fopen("Test.txt", "w");
while (1) {
do {
nbytes = read(s, &frame, sizeof(struct canfd_frame));
} while (nbytes == 0);
msg.id.ext = frame.can_id;
msg.dlc = frame.len;
if (msg.dlc > 8)
msg.dlc = 8; //Protecci�n hasta adaptar AC3LIB a CANFD
Numas_memcpy(&(msg.data.bdata), &(frame.data), msg.dlc);
can_frame_2_ac3lib(&msg, BUS_VERTICAL);
for(x=0;x<64;x++) buffer[i*64+x] = frame.data[x];
printf("%d \r\n",frame.data[x]);
printf("i:%d \r\n",i);
// Copiar datos a fichero.wav y reproducirlo simultaneamente
if (i == 3) {
printf("Datos IN\r\n");
write_wav("prueba.wav",256 , (short int *)buffer, 16000);
//fwrite(buffer,1,sizeof(buffer),fPtr);
//fclose(fPtr);
system("aplay prueba.wav -f cd");
i = 0;
system("rm prueba.wav");
}
i++;
}
32 first bytes of the audio file being recorded
In the picture, as you can see, the data is being recorded. moreover, this data is the same data as in the ADC, but when I play it, I only hear noise.
Simplify the problem first. Make sure you can transmit known data from one end to the other first at low rates. I'm sure the suggestion below will sound far too trivial. But until you are absolutely confident you understand it all, I predict you sill have many struggles.
Slowly - one frame per second, or even slower.
Learn to send one 0x55 byte from one end to the other and verify at the receiver.
Learn to send a few 0x55 in one frame and verify.
Learn to send 0x12345678 - verify it ends up with the bytes in the right order at the other end
Learn to send a counter. Check it at the receiver, make sure you do not drop any data.
Now do it all again but 10x faster.
Continue until you can send a counter at 10x the rate you need to for the audio without dropping any frames at all, for minutes and then hours.
Stress the rest of the system to make sure it still works under stress.
Only now, can you start to learn about sending audio.
Trust me, you will learn a lot!
I'm just trying to learn to use external ADC and DAC (PT8211) with my PIC32MX534f06h.
So far, my code is just about sampling a signal with my ADC every time a timer-interrupt is triggered, then sending then same signal out to the DAC.
The interrupt and ADC part works fine and have been tested independently, but the voltages that my DAC outputs don't make much sens to me and stay at 2,5V (it's powered at 0 - 5V).
I've tried to feed the DAC various values ranging from 0 to 65534 (16bits DAC so i guess it should be the expected range of the values to feed to it, right?) voltage stays at 2.5V.
I've tried changing the SPI configuration, using different SPIs (3 and 4) and DACs (I have one soldered to my pcb, soldered to SPI3, and one one breadboard, linked to SPI4 in case the one soldered on my board was defective).
I made sure that the chip selection line works as expected.
I couldn't see the data and clock that are transmissed since i don't have a scope yet.
I'm a bit out of ideas now.
Chip selection and SPI configuration settings
signed short adc_value;
signed short DAC_output_value;
int Empty_SPI3_buffer;
#define Chip_Select_DAC_Set() {LATDSET=_LATE_LATE0_MASK;}
#define Chip_Select_DAC_Clr() {LATDCLR=_LATE_LATE0_MASK;}
#define SPI4_CONF 0b1000010100100000 // SPI on, 16-bit master,CKE=1,CKP=0
#define SPI4_BAUD 100 // clock divider
DAC output function
//output to external DAC
void DAC_Output(signed int valueDAC) {
INTDisableInterrupts();
Chip_Select_DAC_Clr();
while(!SPI4STATbits.SPITBE); // wait for TX buffer to empty
SPI4BUF=valueDAC; // write byte to TX buffer
while(!SPI4STATbits.SPIRBF); // wait for RX buffer to fill
Empty_SPI3_buffer=SPI4BUF; // read RX buffer
Chip_Select_DAC_Set();
INTEnableInterrupts();
}
ISR sampling the data, triggered by Timer1. This works fine.
ADC_input inputs the data in the global variable adc_value (12 bits, signed)
//ISR to sample data
void __ISR( _TIMER_1_VECTOR, IPL7SRS) Test_data_sampling_in( void)
{
IFS0bits.T1IF = 0;
ADC_Input();
//rescale the signed 12 bit audio values to unsigned 16 bits wide values
DAC_output_value = adc_value + 2048; //first unsign the signed 12 bit values (between 0 - 4096, center 2048)
DAC_output_value = DAC_output_value *16; // the scale between 12 and 16 bits is actually 16=65536/4096
DAC_Output(DAC_output_value);
}
main function with SPI, IO, Timer configuration
void main() {
SPI4CON = SPI4_CONF;
SPI4BRG = SPI4_BAUD;
TRISE = 0b00100000;
TRISD = 0b000000110100;
TRISG = 0b0010000000;
LATD = 0x0;
SYSTEMConfigPerformance(80000000L); //
INTCONSET = _INTCON_MVEC_MASK; /* Set the interrupt controller for multi-vector mode */
//
T1CONbits.TON = 0; /* turn off Timer 1 */
T1CONbits.TCKPS = 0b11; /* pre-scale = 1:1 (T1CLKIN = 80MHz (?) ) */
PR1 = 1816; /* T1 period ~ ? */
TMR1 = 0; /* clear Timer 1 counter */
//
IPC1bits.T1IP = 7; /* Set Timer 1 interrupt priority to 7 */
IFS0bits.T1IF = 0; /* Reset the Timer 1 interrupt flag */
IEC0bits.T1IE = 1; /* Enable interrupts from Timer 1 */
T1CONbits.TON = 1; /* Enable Timer 1 peripheral */
INTEnableInterrupts();
while (1){
}
}
I would expect to see the voltage at the ouput of my DAC to mimic those I put at the input of my ADC, instead the DAC output value is always constant, no matter what I input to the ADC
What am i missing?
Also, when turning the SPIs on, should I still manually manage the IO configuration of the SDI SDO SCK pins using TRIS or is it automatically taken care of?
First of all I agree that the documentation I first found for PT8211 is rather poor. I found extended documentation here. Your DAC (PT8211) is actually an I2S device, not SPI. WS is not chip select, it is word select (left/right channel). In I2S, If you are setting WS to 0, that means the left channel. However it looks like in the extended datasheet I found that WS 0 is actually right channel (go figure).
The PIC you've chosen doesn't seem to have any I2S hardware so you might have to bit bash it. There is a lot of info on I2S though ,see I2S bus specification .
There are some slight differences with SPI and I2C. Notice that the first bit is when WS transitions from high to low is the LSB of the right channel. and when WS transitions from low to high, it is not the LSB of the left channel. Note that the output should be between 0.4v to 2.4v (I2S standard), not between 0 and 5V. (Max is 2.5V which is what you've been seeing).
I2S
Basically, I'd try it with the proper protocol first with a bit bashing algorithm with continuous flip flopping between a left/right channel.
First of all, thanks a lot for your comment. It helps a lot to know that i'm not looking at a SPI transmission and that explains why it's not working.
A few reflexions about it
I googled Bit bashing (banging?) and it seems to be CPU intensive, which I would definately try to avoid
I have seen a (successful) projet (in MikroC) where someone transmit data from that exact same PIC, to the same DAC, using SPI, with apparently no problems whatsoever So i guess it SHOULD work, somehow?
Maybe he's transforming the data so that it works? here is the code he's using, I'm not sure what happens with the F15 bit toggle, I was thinking that it was done to manage the LSB shift problem. Here is the piece of (working) MikroC code that i'm talking about
valueDAC = valueDAC + 32768;
valueDAC.F15 =~ valueDAC.F15;
Chip_Select_DAC = 0;
SPI3_Write(valueDAC);
Chip_Select_DAC = 1;
From my understanding, the two biggest differences between SPI and I2S is that SPI sends "bursts" of data where I2S continuously sends data. Another difference is that data sent after the word change state is the LSB of the last word.
So i was thinking that my SPI is triggered by a timer, which is always the same, so even if the data is not sent continuously, it will just make the sound wave a bit more 'aliased' and if it's triggered regularly enough (say at 44Mhz), it should not be SO different from sending I2S data at the same frequency, right?
If that is so, and I undertand correctly, the "only" problem left is to manage the LSB-next-word-MSB place problem, but i thought that the LSB is virtually negligible over 16bit values, so if I could just bitshift my value to the right and then just fix the LSB value to 0 or 1, the error would be small, and the format would be right.
Does it sounds like I have a valid 'Mc-Gyver-I2S-from-my-SPI' or am I forgetting something important?
I have tried to implement it, so far without success, but I need to check my SPI configuration since i'm not sure that it's configured correctly
Here is the code so far
SPI config
#define Chip_Select_DAC_Set() {LATDSET=_LATE_LATE0_MASK;}
#define Chip_Select_DAC_Clr() {LATDCLR=_LATE_LATE0_MASK;}
#define SPI4_CONF 0b1000010100100000
#define SPI4_BAUD 20
DAaC output function
//output audio to external DAC
void DAC_Output(signed int valueDAC) {
INTDisableInterrupts();
valueDAC = valueDAC >> 1; // put the MSB of ValueDAC 1 bit to the right (becase the MSB of what is transmitted will be seen by the DAC as the LSB of the last value, after a word select change)
//Left channel
Chip_Select_DAC_Set(); // Select left channel
SPI4BUF=valueDAC;
while(!SPI4STATbits.SPITBE); // wait for TX buffer to empty
SPI4BUF=valueDAC; // write 16-bits word to TX buffer
while(!SPI4STATbits.SPIRBF); // wait for RX buffer to fill
Empty_SPI3_buffer=SPI4BUF; // read RX buffer (don't know why we need to do this here, but we do)
//SPI3_Write(valueDAC); MikroC option
// Right channel
Chip_Select_DAC_Clr();
SPI4BUF=valueDAC;
while(!SPI4STATbits.SPITBE); // wait for TX buffer to empty
SPI4BUF=valueDAC; // write 16-bits word to TX buffer
while(!SPI4STATbits.SPIRBF); // wait for RX buffer to fill
Empty_SPI3_buffer=SPI4BUF;
INTEnableInterrupts();
}
The data I send here is signed, 16 bits range, I think you said that it's allright with this DAC, right?
Or maybe i could use framed SPI? the clock seems to be continous in this mode, but I would still have the LSB MSB shifting problem to solve.
I'm a bit lost here, so any help would be cool
In an attempt to understand C memory alignment or whatever the term is (data structure alignment?), i'm trying to write code that results in a alignment error. The original reason that brought me to learning about this is that i'm writing data parsing code that reads binary data received over the network. The data contains some uint32s, uint64s, floats, and doubles, and i'd like to make sure they are never corrupted due to errors in my parsing code.
An unsuccessful attempt at causing some problem due to misalignment:
uint32_t integer = 1027;
uint8_t * pointer = (uint8_t *)&integer;
uint8_t * bytes = malloc(5);
bytes[0] = 23; // extra byte to misalign uint32_t data
bytes[1] = pointer[0];
bytes[2] = pointer[1];
bytes[3] = pointer[2];
bytes[4] = pointer[3];
uint32_t integer2 = *(uint32_t *)(bytes + 1);
printf("integer: %u\ninteger2: %u\n", integer, integer2);
On my machine both integers print out the same. (macbook pro with Intel 64 bit processor, not sure what exactly determines alignment behaviour, is it the architecture? or exact CPU model? or compiler maybe? i use Xcode so clang)
I guess my processor/machine/setup supports unaligned reads so it takes the above code without any problems.
What would a case where parsing of say an uint32_t would fail because of code not taking alignment in account? Is there a way to make it fail on a modern Intel 64 bit system? Or am i safe from alignment errors when using simple datatypes like integers and floats (no structs)?
Edit: If anyone's reading this later, i found a similar question with interesting info: Mis-aligned pointers on x86
Normally, the x86 architecture doesn't have alignment requirements [except for some SIMD instructions like movdqa).
However, since you're trying to write code to cause such an exception ...
There is an alignment check exception bit that can be set into the x86 flags register. If you turn in on, an unaligned access will generate an exception which will show up [under linux at least] as a bus error (i.e. SIGBUS)
See my answer here: any way to stop unaligned access from c++ standard library on x86_64? for details and some sample programs to generate an exception.
I know that there is a lot in internet (http://forum.arduino.cc/index.php?topic=159557.0 for example) about OV7670 and I read a lot about it, but seems something is missing.
First of all I took a look into the way how can we read pixel by pixel from the camera to build the rectangular 600 X 480 image, and this was quite easy to understand considering HREF, VSYNCH and PCLOCK described on documentation here: http://www.voti.nl/docs/OV7670.pdf. I understand XCLOCK as an input I need to give to OV7670 as a kind of cycle controller and RESET would be something to reset it.
So at this point I thought that the functionality of such camera would be covered by wiring the following pins:
D0..D7 - for data (pixel) connected to arduino digital pins 0 to 7 as INPUT on arduino board
XCLK - for camera clock connected to arduino digital pin 8 as OUTPUT from arduino board
PCLK - for pixel clock connected to arduino digital pin 9 as INPUT on arduino board
HREF - to define when a line starts / ends connected to arduino digital pin 10 as INPUT on arduino board
VSYCH - to define when a frame starts / ends connected to arduino digital pin 11 as INPUT on arduino board
GRD - groud connected to arduino GRD
3V3 - 3,3 INPUT connected to arduino 3,3v
RESET - connected to arduino RESET
PWDN - connected to arduino GRD
The implementation for such approach from my point of view would be something like:
Code:
for each loop function do
write high to XCLK
if VSYNCH is HIGH
return;
if HREF is LOW
return;
if lastPCLOCK was HIGH and currentPCLOCK is LOW
readPixelFromDataPins();
end for
My readPixelFromDataPins() basically read just the first byte (as I'm just testing if I can even read something from the camera), and it is written as follows:
Code:
byte readPixelFromDataPins() {
byte result = 0;
for (int i = 0; i < 8; i++) {
result = result << 1 | digitalRead(data_p[i]);
}
return result;
}
In order to check if something is being read from the camera I just print it to the Serial 9600, the byte read from data pins as a number. But currently I'm receiving only zero values. The code I'm using to retrieve an image is stored here: https://gist.github.com/franciscospaeth/8503747.
Did somebody that makes OV7670 work with Arduino already figure out what am I doing wrong? I suppose I'm using the XCLOCK wrongly right? What shall I do to get it working?
I searched a lot and I didn't found any SSCCE (http://sscce.org/) for this camera using arduino, if somebody have it please let me know.
This question is present on arduino forum (http://forum.arduino.cc/index.php?topic=211741.0) too.
your idea is not bad but ...
the xclock need to be a clock (in your program is just a transition from 0 to 1 and is freezing there)
you need also to use I2C with SIOC and SIOD for configuring the camera (or you can use the default settings, but I am not sure if is the correct output format for you, 30F/s,VGA, YUV format ....)
your code execution is slower using the serial output in the same loop with reading data
I will recommend you to toggle the xclock pin and to move the pixel print in a if(). Also you will be able to read Data only in a very precise time, if you want to read only one byte, than after a transition from 0 to 1 of HREF you need to wait for a new transition from 0 to 1 of PCLK (you will be able to see only one 0-1 transition of HREF after 784x2 transitions of PCLK, (640 active pixels + 144 dead time for each line) x 2 (for YUV or RGB are 2 bytes received for each pixel) )
Hello I am Mr_Arduino from the arduino forums. Your issue is that you are reading pixels too slow please do not use digital read to do such a thing. Also if you insist on using a separate function just to read a byte make sure the function is being inlined. You can do this by declaring your function as static inline. Also as mentioned above how are you generating the clock. You can generate the XCLK using PWM on the arduino.
I have created a working example here:
https://github.com/ComputerNerd/arduino-camera-tft/blob/master/captureimage.c
Edit: a 3rd party has copied part but not all of the code from the above link into the answer here. However, the link must remain as the code posted below requires additional files from that source to actually work.
Edit 2: Removed irrelevant code. You will need to modify what you do with the data.
void capImg(void){
cli();
uint8_t w,ww;
uint8_t h;
w=160;
h=240;
tft_setXY(0,0);
CS_LOW;
RS_HIGH;
RD_HIGH;
DDRA=0xFF;
//DDRC=0;
#ifdef MT9D111
while (PINE&32){}//wait for low
while (!(PINE&32)){}//wait for high
#else
while (!(PINE&32)){}//wait for high
while (PINE&32){}//wait for low
#endif
while (h--){
ww=w;
while (ww--){
WR_LOW;
while (PINE&16){}//wait for low
PORTA=PINC;
WR_HIGH;
while (!(PINE&16)){}//wait for high
WR_LOW;
while (PINE&16){}//wait for low
PORTA=PINC;
WR_HIGH;
while (!(PINE&16)){}//wait for high
WR_LOW;
while (PINE&16){}//wait for low
PORTA=PINC;
WR_HIGH;
while (!(PINE&16)){}//wait for high
WR_LOW;
while (PINE&16){}//wait for low
PORTA=PINC;
WR_HIGH;
while (!(PINE&16)){}//wait for high
}
}
CS_HIGH;
sei();
}
You can also find it on github.
You can use my instruction: how to retrieve image from ov7670 It contains all the steps you need. There is also instuction to setup FrameGrabber: how to run framegrabber
I realize there is not any public documentation about the use of the isight light sensor, however programs such as ShadowBook (shown here) are able to access the the brightness data and I was simply wondering if anyone has been able to achieve a similar result and know how to access this sensor? Thanks!
You can access the light sensor with IOService, from the IOKit library. The name for the light sensor is "AppleLMUController". Here's a good example: light sensor.
Simply put, get the service like this: io_service_t service = IOServiceGetMatchingService(kIOMasterPortDefault, IOServiceMatching("AppleLMUController"));
Then, connect to the service using:
io_connect_t port = 0;
IOServiceOpen(service, mach_task_self(), 0, &port);
Get the light levels using: IOConnectMethodScalarIScalarO(port, 0, 0, 2, &left, &right);
Where left and right are integers that now hold the light levels of the sensors.
Note that many IOService methods return a kern_return_t variable, which will hold KERN_SUCCESS, unless the method failed. Also be sure to release the service object using IOObjectRelease(service);
EDIT: On second thought, IOConnectMethodScalarIScalarO() appears to be deprecated.
Instead, use:
uint32_t outputs = 2;
uint64_t values[outputs];
IOConnectCallMethod(port, 0, nil, 0, nil, 0, values , &outputs, nil, 0);
The left and right values will be stored in values[0] and values[1] respectively. Be aware that not all MacBooks work this way: on my mid 2010 15'' pro, both values are the same, as the light sensor is in the iSight camera.