RoboSavvy Forum

USART Question

2008-05-30T08:09:06+01:00

bergere wrote:
So UDR0 is just 4 the motors and the UDR1 for the communication between CM-5 and "Terminal"

Note that UDR1 is used also for zigbee option.

You have to manage corresponding i/o pins to select output interface (zigbee/terminal). That should be well initialized by default if you didn't change PORTD configuration.

I concerns these pins:

Switch to output direction and to true (1) state these pins to select pc direction:
BIT_ZIGBEE_RESET PortD4;
BIT_ENABLE_RXD_LINK_PC PortD5;
BIT_ENABLE_RXD_LINK_ZIGBEE PortD6;

switch this one to input direction:
BIT_LINK_PLUGIN Port_D7;

a very fast configuration that works : (wrote inAda)

Code:: ------------------------- -- Initialize_Pc_Rs232 -- ------------------------- procedure Initialize_Pc_Rs232 is BIT_ZIGBEE_RESET : constant Pin := Port_D4; BIT_ENABLE_RXD_LINK_PC : constant Pin := Port_D5; BIT_ENABLE_RXD_LINK_ZIGBEE : constant Pin := Port_D6; BIT_LINK_PLUGIN : constant Pin := Port_D7; begin -- Init Port -- Set output Zigbee and pc control pins; Switch_Output(BIT_ZIGBEE_RESET); -- (switch_Ouput writes 1 in corresponding DDRx) Switch_Output(BIT_ENABLE_RXD_LINK_PC); Switch_Output(BIT_ENABLE_RXD_LINK_ZIGBEE); Switch_Input(BIT_LINK_PLUGIN); --(no pull up) -- (switch_Input writes 0 in corresponding DDRx) -- Select pc connection Output(BIT_ZIGBEE_RESET, true); -- ('ouput' writes value in corresponding PORTx) Output(BIT_ENABLE_RXD_LINK_PC, true); Output(BIT_ENABLE_RXD_LINK_ZIGBEE, true); -- Init USART 1 Set(UBRR1H, 0); Set(UBRR1L, 34);--Default_Bdr : 56700 bds; -- (note we disabled interrupt before all initializations... in case of...) Set(UCSR1C, 16#06#); -- 8bits, 1 stop, no parity Set(UCSR1A, 16#02#);-- Receive Data Bit 8 Set_Bit(UCSR1B, RXCIE1_Bit, false);-- RxD interrupt disabled Set_Bit(UCSR1B, RXEN1_Bit, true); -- Rx enable Set_Bit(UCSR1B, TXCIE1_Bit, false);-- TxD interrupt disabled Set_Bit(UCSR1B, TXEN1_Bit, true); -- Tx enable end Initialize_Pc_Rs232;

For a good unitary test, without any doubt on your terminal conf, you can link Rx and Tx together and control that this echoes well... telling the result to a DEL...)

Statistics: Posted by le fatumbi — Fri May 30, 2008 8:09 am

USART Question

2008-05-28T10:07:15+01:00

So UDR0 is just 4 the motors and the UDR1 for the communication between CM-5 and "Terminal".

Thx 4 Help

Statistics: Posted by bergere — Wed May 28, 2008 10:07 am

USART Question

2008-05-27T16:34:20+01:00

I trust you are referring to CM5 ?

In this case one UART is used to communicate with the AX12 servos and the other, to communicate with PC/Zigbee/Bluetooth.

For this type of setup you can find some working example code posted here previously. see the Bioloid Wiki for links.

Statistics: Posted by limor — Tue May 27, 2008 4:34 pm

USART Question

2008-05-26T13:55:25+01:00

Hello again,

I want to transmit Data via USART. This works fine for UDR1 on my Atmega128. I was surprised that works without any initialisation.

Code:: void TxD81(byte bTxdData) { while(!(bit_is_set(UCSR1A,5))); UDR1 = bTxdData; }

But if i try to use UDR0 it doesn´t work. So i want to initialise UDR0.

Code:: void USART_Init( unsigned int ubrr ) { /* Activate USART Transmitter */ UCSR0B |= (1< /* Set 1 Stop Bit */ UCSR0C &= ~(1< /* Activate Asynchronus Transfermode */ UCSR0C &= ~(1< /* Choose Frame Format */ UCSR0C |= (1< UCSR0C |= (1< UCSR0B &= ~(1< /* Synchronisation */ UBRR0H = 0x00; UBRR0L = 0x22; }

My UDRR is 34 for Asynchronous Transfer Mode.

Question Number 1: Why i havn´t to initalise UDR1???
Question Number 2: Is this Initialisation correct? Or do i forgot something?
Question Number 3: Maybe UDR0 isn´t Used for Transmitting Data because i found that his UBRRL isn´t correctly defined in the iom128.h file.

For example:

Code:: /* USART0 Baud Rate Register High */ #define UBRR0H _SFR_MEM8(0x90) /* USART0 Control and Status Register C */ #define UCSR0C _SFR_MEM8(0x95) /* USART1 Baud Rate Register High */ #define UBRR1H _SFR_MEM8(0x98) /* USART1 Baud Rate Register Low*/ #define UBRR1L _SFR_MEM8(0x99) /* USART1 Control and Status Register B */ #define UCSR1B _SFR_MEM8(0x9A) /* USART1 Control and Status Register A */ #define UCSR1A _SFR_MEM8(0x9B) /* USART1 I/O Data Register */ #define UDR1 _SFR_MEM8(0x9C) /* USART1 Control and Status Register C */ #define UCSR1C _SFR_MEM8(0x9D)

You can see that there isnt defined the UBRRL and many other things. But in the Atmega 128 Documentation they are listed. For example
||$09 ($29)|| UBRR0L USART0 Baud Rate Register Low
But it isn´t defined in the iom128.h. Why?

OK I hope you understand my problem despite my bad english.

Statistics: Posted by bergere — Mon May 26, 2008 1:55 pm