I'm interfacing an SD card to ATmega128 using EFSL.
Card gets initialised, but I get an error saying "Unknown error 0xff(see sandisk docs p5-13)"... on serial port output.
That's not all, I hv used 'sprintf' to form strings which I display on serial port. The puzzling thing is, I'm also getting the actual formatting characters like "%02d" on the output ! I think my application itself is crashing. I can give my source code, but it's too big. If anyone wants to look at it , i'll copy paste it here.
I've also checked the sandisk docs p5-13 but I can't figure it out...
I'm gonna need help on this one guys...
Please let me know if anyone knows anything about this
Thanxs...
I happen to have written some code for an ATmega8 and written my own printf function that outputs to the serial port here.
the SerWrite function is your function that transfers a 0-terminated unsigned char array to the serial port.
#define SIZE_STATUS 80
void ser_printf(const char *fmt, ...) {
va_list args;
uchar STATUS[SIZE_STATUS];
va_start(args, fmt);
uchar s = (uchar) vsnprintf(STATUS, SIZE_STATUS, fmt, args);
va_end(args);
SerWrite(STATUS, s);
}
I don't know how, but problem was solved when I used a different card. I tried two 1/2 GB cards with FAT32 formatting; both didn't work, But the card that worked was 16 MB canon card with FAT12 formatting.I'm trying to figure this out. I'll post the answer if I find it,
Thanks anyway guys...
Related
I am trying to implement a system so that it retrieves sound and extracts the mfcc of it. I'd like to implement my own mfcc function because librosa library wasn't implemented in C and other implementations of mfcc extractions doesn't yield the same outputs as librosa library does.
So I wrote a code, however, when I would like create hanning window, program doesn't take a step further and always stays the same statement while debugging. The statement is below:
float *mul = malloc(sizeof(float)*fftsize);
The whole code is as follows:
float* hanning(int fftsize){
float *mul = malloc(sizeof(float)*fftsize);
for (int i = 0; i<fftsize; i++){
mul[i] = 0.5 * (1 - cos(2*PI*i/(fftsize-1)));
}
return mul;
}
I put an LCD code to all error handler functions in stm32f7xx_it.c file to determine which fault I'm facing, and I see that it is hard_fault.
So what's the problem? I hope the issue is explained clearly. Due to the privacy, I couldn't put here whole code. Sorry for that. Thx in advance for your response.
Edit: I am chaning malloc to normal array with a variable length array. But still it takes me to HardFault_Handler function. SCB->SHCSR returns sometimes 65535 and sometimes 1.
I'm writing 8-bit PIC microcontroller C code in Microchip's MPLAB X tool using their XC8 compiler for a demo / evaluation board for a sensor IC. The PIC I'm using has multiple serial ports, so I'm using UART2 to output only sensor data. I wanted to be able to format the output data for hex or decimal so I have stdio redirected to this port. The Rx side of UART2 is unused.
UART1 is used for command and control. This port needs to be able to output ASCII messages such as "Enter the register address:". The sensor is highly configurable, so my code initializes it with default values, but the user can halt sampling, read and write registers and re-start sampling.
Since I can't use printf when writing to UART1, I had to find another way to do this. Here's an example of what I'm doing. The file is large so I'm just cutting and pasting the relevent stuff here:
char msgString[64];
switch(command)
{
case (READCMD): // Read command
{
if (SERIAL_STATE_IDLE == serialPortState)
{
strcpy (msgString, "Input Read Address Hex Value 00-18");
Display_PrintMessage();
Display_PrintChar(prompt);
serialPortState = SERIAL_STATE_READ;
}
...
void Display_PrintMessage(void)
{
msgLength=strlen(msgString);
for (i=0; i<msgLength; ++i)
{
UART1_Write(msgString[i]);
}
Display_PrintChar(newLine);
}
void Display_PrintChar(char c)
{
UART1_Write(c);
}
I've verified that the port is working by writing some characters out to it early in main and they do appear on my terminal. I think the problem is with how I'm using the strcpy function. In the MPLAB debugger it appears that msgString is still all null characters after the strcpy executes. The strlen function may see msgString as zero length, hence, nothing prints out.
I would love to hear what you think may be wrong with my code, or, please suggest another way of accomplishing what I need.
Thanks in advance for any and all responses, they are much appreciated.
CobraRGuy
So I tried using code from another post around here to see if I could use it, it was a code meant to utilize a potentiometer to move a servo motor, but when I attempted to compile it is gave the error above saying No operator "=" matches these operands in "Servo_Project.cpp". How do I go about fixing this error?
Just in case ill say this, the boards I was trying to compile the code were a NUCLEO-L476RG, the board from the post I mentioned utilized Nucleo L496ZG board and a Tower Pro Micro Servo 9G.
#include "mbed.h"
#include "Servo.h"
Servo myservo(D6);
AnalogOut MyPot(A0);
int main() {
float PotReading;
PotReading = MyPot.read();
while(1) {
for(int i=0; i<100; i++) {
myservo = (i/100);
wait(0.01);
}
}
}
This line:
myservo = (i/100);
Is wrong in a couple of ways. First, i/100 will always be zero - integer division truncates in C++. Second, there's not an = operator that allows an integer value to be assigned to a Servo object. YOu need to invoke some kind of Servo method instead, likely write().
myservo.write(SOMETHING);
The SOMETHING should be the position or speed of the servo you're trying to get working. See the Servo class reference for an explanation. Your code tries to use fractions from 0-1 and thatvisn't going to work - the Servo wants a position/speed between 0 and 180.
You should look in the Servo.h header to see what member functions and operators are implemented.
Assuming what you are using is this, it does have:
Servo& operator= (float percent);
Although note that the parameter is float and you are passing an int (the parameter is also in the range 0.0 to 1.0 - so not "percent" as its name suggests - so be wary, both the documentation and the naming are poor). You should have:
myservo = i/100.0f;
However, even though i / 100 would produce zero for all i in the loop, that does not explain the error, since an implicit cast should be possible - even if clearly undesirable. You should look in the actual header you are using to see if the operator= is declared - possibly you have the wrong file or a different version or just an entirely different implementation that happens to use teh same name.
I also notice that if you look in the header, there is no documentation mark-up for this function and the Servo& operator= (Servo& rhs); member is not documented at all - hence the confusing automatically generated "Shorthand for the write and read functions." on the Servo doc page when the function shown is only one of those things. It is possible it has been removed from your version.
Given that the documentation is incomplete and that the operator= looks like an after thought, the simplest solution is to use the read() / write() members directly in any case. Or implement your own Servo class - it appears to be only a thin wrapper/facade of the PwmOut class in any case. Since that is actually part of mbed rather than user contributed code of unknown quality, you may be on firmer ground.
I'm currently trying to do some tests with the buffer overflow vulnerability.
Here is the vulnerable code
void win()
{
printf("code flow successfully changed\n");
}
int main(int argc, char **argv)
{
volatile int (*fp)();
char buffer[64];
fp = 0;
gets(buffer);
if(fp) {
printf("calling function pointer, jumping to 0x%08x\n", fp);
fp();
}
}
The exploit is quite sample and very basic: all what I need here is to overflow the buffer and override the fp value to make it hold the address of win() function.
While trying to debug the program, I figured out that fb is placed below the buffer (i.e with a lower address in memory), and thus I am not able to modify its value.
I thought that once we declare a local variable x before y, x will be higher in memory (i.e at the bottom of the stack) so x can override y if it exceeds its boundaries which is not the case here.
I'm compiling the program with gcc gcc version 5.2.1, no special flags (only tested -O0)
Any clue?
The order of local variable on the stack is unspecified.
It may change between different compilers, different versions or different optimization options. It may even depend on the names of the variables or other seemingly unrelated things.
The order of local variables on the stack is not defined until compile/link (build) time. I'm no expert certainly, but I think you'd have to do some sort of a "hex dump", or perhaps run the code in a debugger environment to find out where it's allocated. And I'd also guess that this would be a relative address, not an absolute one.
And as #RalfFriedl has indicated in his answer, the location could change under any number of compiler options invoked for different platforms, etc.
But we do know it's possible to do buffer overflows. Although you do hear less about them now due to defensive measures such as address space layout randomization (ASLR), they're still around and paying the bills for someone I'd guess. There are of course many many online articles on the subject; here's one that seems fairly current(https://www.synopsys.com/blogs/software-security/detect-prevent-and-mitigate-buffer-overflow-attacks/).
Good luck (should you even say that to someone practicing buffer overflow attacks?). At any rate, I hope you learn some things, and use it for good :)
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