USART design consideration

Started by tguclu in comp.arch.embedded10 years ago 6 replies

Hi everyone ,i'm new to group. In my project i need to use 3xUSART ports in order to build a SDLC network. USART ports will function as the phy...

Hi everyone ,i'm new to group. In my project i need to use 3xUSART ports in order to build a SDLC network. USART ports will function as the phy of SDLC as V.24 Anyway , this is not the point. Each USART will work at 64kbps. So there is a network traffic of almost 192 kps. The problem ise my cpu board doesn't have 2x UART but no USART port so i have use a microcontroller with at least 3xUS...


USART Transmit Issue

Started by elamaranv in comp.arch.embedded10 years ago 5 replies

Hi All, I am facing an issue with the USART Transmit. My code is as shown below...... #include #include void main( void ) {...

Hi All, I am facing an issue with the USART Transmit. My code is as shown below...... #include #include void main( void ) { char group[10]="Microchip "; int i; OpenUSART( USART_TX_INT_OFF & USART_RX_INT_OFF & USART_ASYNCH_MODE & USART_EIGHT_BIT & USART_CONT_RX & USART_BRGH_HIGH, 129 ); while( 1 ) { for(i=0; i


PIC P18F4550 USART Receive Problem

Started by Anonymous in comp.arch.embedded10 years ago

Hi, I'm using the Microchip PICDEM board to test USART on the 4550 PIC. I'm using the default settings and the test code to tx/rx data...

Hi, I'm using the Microchip PICDEM board to test USART on the 4550 PIC. I'm using the default settings and the test code to tx/rx data via USART. I can Tx data but Rx doesn't work at all. I've tried all routes to get it working - any ideas? Is there any pins I need to set up although I've already tested with: RISCbits.TRISC7=1; and TRISCbits.TRISC6=0; but still not working on Rx. All B...


How accurate/tolerant is the PIC USART clock rate?

Started by pome...@hotmail.com in comp.arch.embedded11 years ago 10 replies

I am looking at a design which uses a PIC18F8520 whose USART is connected to a PC serial port running at a fairly high data rate. I am also...

I am looking at a design which uses a PIC18F8520 whose USART is connected to a PC serial port running at a fairly high data rate. I am also looking at the design of a serial port instantiated in an FPGA connected to the same data stream in an RS-485 network. Having to deal with the internal details of the FPGA "USART" makes me wonder about the internal details of the PIC USART. FOr instanc...


Atmega8 Sleep mode doesn't work with USART

Started by Anonymous in comp.arch.embedded12 years ago 5 replies

Hi. I'd like to use sleep operation with USART but when I use USART with sleep operation, the system was crashed. my code like...

Hi. I'd like to use sleep operation with USART but when I use USART with sleep operation, the system was crashed. my code like this. #include #include #include #include void Uart_Put_Char(unsigned char data) { while ( !( UCSRA & (1 <


Pic18f252 usart problem

Started by PigPOg in comp.arch.embedded9 years ago 5 replies

Hello all I'm probably overlooking the obvious but I can't seem to get the USART on the 18F252 working. I've tested Port RC6 to see if...

Hello all I'm probably overlooking the obvious but I can't seem to get the USART on the 18F252 working. I've tested Port RC6 to see if anything is being transmitted but the output remains high. I suspect that I haven't configured the associated registers properly or the Test Routine is wrong. Using other code I know the port works OK. Below are a few details, can anyone advise please? ...


USART microcontroller communication

Started by ahme...@gmail.com in comp.arch.embedded12 years ago 3 replies

Hello all, Consider the atmega48 microcontroller by Atmel corp. I want to connects its USART to my PC. Basically i want the microcontroller to...

Hello all, Consider the atmega48 microcontroller by Atmel corp. I want to connects its USART to my PC. Basically i want the microcontroller to talk to to computer. How can i do this? 1. Using a serial port? 2. Can a build my own PCI/ISA card for the pc so that it can read from the uC and send the data to the computer where other devices can use the information? 3. Other options?...


ATmega8535 and USART post-initialisation delay required?

Started by Joe in comp.arch.embedded13 years ago 3 replies

Is there a requirement to delay using the USART (at least for asynchronous transmission) for a period of time after initially setting it up...

Is there a requirement to delay using the USART (at least for asynchronous transmission) for a period of time after initially setting it up and enabling interupts until transmitting the first character? I ask, because when I set it up and then immediately use it to output a character (or string of characters), they are consistently wrong. I tried outputing the following string: "sys init...


HELP!! Pleas....PIC16F627a can't make usart receive interrupt work

Started by Anbeyon in comp.arch.embedded11 years ago 1 reply

Hi Can someone take a peek at the code below and see if I have enabled the USART on the PIC16F627A correctly please. All I want to do right...

Hi Can someone take a peek at the code below and see if I have enabled the USART on the PIC16F627A correctly please. All I want to do right now is set up a pic running @ 10MHz to 28800 baud and jump to my interrupt routine when it see a char. I can't make it happen. I have done this lots f times on other PICS but am getting nowhre in the 627A. Please also see the lines reagrding TR...


AT91RM900 USART problem

Started by Anonymous in comp.arch.embedded11 years ago 11 replies

We have been developing code for the AT91RM9200 and have found problems with the UART when running the USART 1.5% slower than the selected boaud...

We have been developing code for the AT91RM9200 and have found problems with the UART when running the USART 1.5% slower than the selected boaud rate. A natural consequence with certain clocks and the available divisors available. The problem is that framing errors are not correctly detected. i.e for 115200 we have a 18.432 MHz crystal clock, and processors runs at 179.712MHz, main clock=59....


AT91SAM7 USART

Started by comp.zrch.embedded in comp.arch.embedded8 years ago

I have an issue with the baud rate clock on a AT91SAM7S processor. The processor will run from an external 18.432MHz crystal and run at this...

I have an issue with the baud rate clock on a AT91SAM7S processor. The processor will run from an external 18.432MHz crystal and run at this frequency or will divide this down to 1.152MHz when it is required to run in low power mode. We also need to use the USART and do not want to loose any characters that are currently being received when we we switch over clock frequency. We also which a...


Unusual USART behaviour on AVR AT90CAN128

Started by Rav in comp.arch.embedded10 years ago 5 replies

Hi, I have found some unusual USART behaviour when i was trying to send characters from USART1 of my AT90CAN128 to the PC terminal. Below...

Hi, I have found some unusual USART behaviour when i was trying to send characters from USART1 of my AT90CAN128 to the PC terminal. Below is the code that i have been using for the same. The problem is, what i am getting on my PC hyperterminal is some garbage. I did some calculations and found that there was a difference of 128 between the characters sent and the character received. For ex...


PDC w/ USART

Started by jgoshorn in comp.arch.embedded12 years ago 1 reply

Hello All, I am implementing hardware handshaking with USART on AT91RM9200 board (24.6.3.12 in data sheet). I need to make RTS signal...

Hello All, I am implementing hardware handshaking with USART on AT91RM9200 board (24.6.3.12 in data sheet). I need to make RTS signal orignating from CP drop to allow the remote device with which the CPU is communicating t transmit information to the CPU. The data sheet states that the USAR needs requires the use of the PDC (peripheral DMA controller) fo reception when using hardware han...


Nucleus PLUS sdc.c usart tx buffer seems always full

Started by aclassifier in comp.arch.embedded10 years ago 2 replies

We have a case where we 1) some times loose send character on the usart and now 2) Nucleus _always_ sees a full tx buffer (after sending a...

We have a case where we 1) some times loose send character on the usart and now 2) Nucleus _always_ sees a full tx buffer (after sending a "random" number of characters first - several KB) and does a NU_Sleep(1) in a loop forever. This seems to hog the machine. We have sdc.c version "Nucleus PLUS\Integrator\RVCT 1.15.17" and run on for ARM9. If this is,a s I presume, an sdc.c error - doe...


how to initializatize/re-configure usart?

Started by bcincin in comp.arch.embedded10 years ago 2 replies

Hi. I want to change reset uart and change baud rate with an interface (combobox) on windows. At the beginning default baud rate is 2400....

Hi. I want to change reset uart and change baud rate with an interface (combobox) on windows. At the beginning default baud rate is 2400. ME2 |= UTXE1 + URXE1; // Enable USART1 TXD/RXD UCTL1 |= CHAR; // 8-bit character UTCTL1 |= SSEL0; // UCLK = ACLK UBR01 = 0x0D; // 32k/2400 - 13.65 UBR11 = 0x00; UMCTL1 = 0x6B; // Modulation UCTL1 &= ~SWRST; // Initialize USART state machine ...


atmel_serial driver modifications for 6Mb/s throughput in synchronous mode

Started by wzab in comp.arch.embedded6 years ago 14 replies

Hi, I need to transmit serial data at rate 6Mb through the AT91SAM9260 USART. I have succesfully modified the driver to work in synchronous...

Hi, I need to transmit serial data at rate 6Mb through the AT91SAM9260 USART. I have succesfully modified the driver to work in synchronous mode (see thread: https://groups.google.com/group/comp.arch.embedded/browse_thre= ad/thread/503dd4dfd723e74f ) However then I have faced strange problems at high data rates. I use USART with DMA. Tha application sets tty into "raw" mode. Anyway at ...


USART, setting of TRIS register needed (PIC 16F-types) ?

Started by Stef Mientki in comp.arch.embedded11 years ago 2 replies

I'm a little bit confused about the TX and RX pins in UART mode. I checked several PIC types: If you read the text carefully, you will read...

I'm a little bit confused about the TX and RX pins in UART mode. I checked several PIC types: If you read the text carefully, you will read several times: "bit SPEN () and the TRIS register have to be set in order to configure the TX and RX pins as the USART" Now look at the schematics of the ports, and see that it doesn't matter to set the TRIS register, because the "peripheral OE" wi...


USART communication in PIC

Started by Anuhas in comp.arch.embedded9 years ago 10 replies

Dear Experts, I want to send some AT commands from a PIC through RS232. Give me the codes in C to send something from PIC that should be...

Dear Experts, I want to send some AT commands from a PIC through RS232. Give me the codes in C to send something from PIC that should be displayed in a hyperterminal Regards Anuhas


Atmel

Started by Peter Keller in comp.arch.embedded9 years ago 19 replies

Hello, I've done some PIC development before, with the PIC16F690, PIC18F4321, etc. and I'm thinking about trying out the Atmel processors...

Hello, I've done some PIC development before, with the PIC16F690, PIC18F4321, etc. and I'm thinking about trying out the Atmel processors since I've heard they have a flat memory space (no banks), a software stack, and other things I am interested in. What would be a good entry level atmel microprocessor to experiment with (maybe having features like USART, SPI, USB, external data/program ...


global jumps and stack

Started by Arnim Zichner in comp.arch.embedded14 years ago 3 replies

Hello! I'm programming two ATmega162s which should do some communication via their USART-interfaces. I'm using the C-programming language with...

Hello! I'm programming two ATmega162s which should do some communication via their USART-interfaces. I'm using the C-programming language with the CodeVision AVR Compiler. I preferred C, because I do not have too much experience in programming in assembly language and to this point everything worked pretty good. But sadly a serious problem occured: My Programm runs in an endless loop ("m...