At first - sorry for my english
I need to read data from serial port (from GPS reciever)
I wrote a small app using SerialPort X2. It works.
But. I read data every 1 sec (on timer fire). And the recieving data is not very well. it could be without some first bytes or last bytes. So I need to read data from the "thread" (I did it when I wrote using Delphi in Windows).
I know that it could be using ObjC, but I am quit newbie in C
If someone have a small example (with tons of comments) on how to do it - it will be very helpfull
thanks
xCode 4, MacOSX 10.6
Related
I am building a SD card/SCSI adapter using NCR 53CF94 IC and STM32.
All goes pretty well, even manged to make my device work to some degree, i.e. accepting all basic commands and even booting from it to DOS. BUT i have a problem, when asking initiator (PC) to write something to my device , all goes well i get the block address and the data. Then i write the data to SD card and finally responding with status=0 and message=0 to complete the write command, but the initiaor never increasing the secoor number to continue to write proccess and always tries to write the first one, then after few attempts it gives error on the PC (Error writing to drive...). I can't figure it out why the initiaor is not satisfied with the GOOD status and message. Do i need to send some specific data back to the initiator ? Linke CRC ? Or there is some specific command i need to issue for 53C94 ?
Banging my head for few days now.
Need your assistance please.
Thanks !
Artiom.
I figured it out. I was writing 512 byte blocks to a 256 byte array. I'm not sure how this is related to the issue, but after fixing the size everything started to work.
Situation:
I'm trying to manipulate/hack a Debian kernel to be able to use 9-bit UART via the parity hack that you can find reference to everywhere on the NET. Now for some reason Tx is working just fine, but when we look at Rx we're dropping bytes. We're expecting 9 bytes back, including the crc, but we get a variable amount back between 4-7. It will vary with the exact same code run a few times in a row, so it almost appears to be buffer related. Hooking it up to the logic analyzer the response is proper(9 expected bytes) from the slave device, but it is getting "mangled" somewhere low level that I can't track down.
Attempted:
So I started dumping all the bytes(char) that come in here:
static void serial_omap_rdi(struct uart_omap_port *up, unsigned int lsr)
Which still results in only seeing 4-7 bytes of bad data. I'm assuming this is due to parity/framing/FIFO errors but I just can't seem to get any deeper to where I can see exactly where it's failing.
Questions:
Has anyone seen anything like this type of discarded data on the UART line with a linux kernel? If so would you know any possible avenues to take in tracking it down?
Is there anyplace in the kernel I can look to actually dump the bit-by-bit data that is coming into the UART Rx line?
Any help is greatly appreciated as I'm at my wits end understanding how/where exactly the kernel is discarding these bytes...
Platform:
BBB Debian Linux 3.8.13-bone53 armv7l GNU/Linux
16750 UART (I Believe)
I have a a Sparkfun Max 7456 breakout board that I am trying to rewrite the character table to an ASCII format. I have been following the Arduino + MAX7456 OSD thread but cannot seem to load the .mcm file to the breakout board. I have tried hyper terminal and tera term. Tera term allows me to "transfer" the mcm file but I do not get any type of confirmation in the terminal window. When I try simple sample code like "Hello World.ino" I get no response and the default character set is still displayed. Hyper terminal tells me there is a COM port conflict with the Arduino IDE. I know the steps are available in the above mentioned thread but the picture/ code resources have mostly been removed. I don't know if I'm missing something in the code or if I am not using the terminal program correctly. I have the following connections between the breakout board and the Uno and have been trying Arduino code provided at the start of the thread;
Breakout/ Uno;
CS-->D10
SDIN--> D11
SCK--> D12
SDOUT--> D13
+5V
GND
I have tried using wires that are <5cm and >=10cm and I am using NTSC. Can anybody determine what I am doing wrong or point me in the right direction please. Thanks in advance,
I figured out my issue. Using Google translate I was able to get code from;
http://f5mna.free.fr/Arduiexpert.htm
Previously, I was only making the connections listed in the code when the full list is;
D13--> SCLK
D12--> SDOUT
D11--> SDIN
D10--> CS
+5VDC must be applied to the +5V pin on the board as well as a 1k resistor in series with LOS and a 10k with RESET.
As for using tera term. First shutdown the Arduino IDE and open the connection in the terminal program. The code provided in the above link will indicate it is ready for file transfer and will prompt you with a transfer complete message.
All in all, simple solutions but I was a newcomer to a very old thread. Hope this helps anyone else having the same issues in the future.
I am using a FT232RL chip with FTD2XX_NET.dll I've made a program which writes and reads data to/from AVR atmega32 mcu. First writes data, then reads data as answer.
Now, i want to make an event which indicated me if there's available unreaded data, only when AVR sends data to FTDI buffer and ONLY then. Whithout forcing my program to making loops for checking available data. For my purpose, i want to do the mcu to sends data only when he wants, and the PC must to knows when there's new data in FTDI buffer's chip.
I know that It's impossible for the pc to know when AVR sending data to the FTDI. But this which I mean it's that I need some way for my program to know if FTDI have New unreaded data to it's own buffer.
I don't won't to running read operator over and over in an infinity loop as I do now.
You should create a read thread which does your reading in the background. Then from that thread you can signal an even to notify another part of your application when you have data. I'm not sure what language you are using but you should easily be able to find an example of threading and event notification with a Google search.
Well, the question says it all.
What I would like to do is that, every time I power up the micro-controller, it should take some data from the saved data and use it. It should not use any external flash chip.
If possible, please give some code-snippet so that I can use them in AVR studio 4. for example if I save 8 uint16_t data it should load those data into an array of uint16_t.
You have to burn the data to the program memory of the chip if you don't need to update them programmatically, or if you want read-write support, you should use the built-in EPROM.
Pgmem example:
#include <avr/pgmspace.h>
PROGMEM uint16_t data[] = { 0, 1, 2, 3 };
int main()
{
uint16_t x = pgm_read_word_near(data + 1); // access 2nd element
}
You need to get the datasheet for the part you are using. Microcontrollers like these typically contain at least a flash and sometimes multiple banks of flash to allow for different bootloaders while making it easy to erase one whole flash without affecting another. Likewise some have eeprom. This is all internal, not external. Esp since you say you need to save programatically this should work (remember how easy it is to wear out a flash do dont save unless you need to). Either eeprom or flash will meet the requirement of having that information there when you power up, non-volatile. As well as being able to save it programmatically. Googling will find a number of examples on how to do this, in addition to the datasheet you apparently have not read, as well as the app notes that also contain this information (that you should have read). If you are looking for some sort of one time programmable fuse blowing thing, there may be OTP versions of the avr, and you will have to read the datasheets, programmers references and app notes on how to program that memory, and should tell you if OTP parts can be written programmatically or if they are treated differently.
The reading of the data is in the memory map in the datasheet, write code to read those adresses. Writing is described in the datasheet (programmers reference manual, users guide, whatever atmel calls it) as well and there are many examples on the net.