jens/HendiControlFirmware
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

- UART takes baudrate on init

Browse Source 
- UART calculate optimized baud prescaler

git-svn-id: http://moon:8086/svn/projects/HendiControl@47 fda53097-d464-4ada-af97-ba876c37ca34
This commit is contained in:
jens
2019-03-03 08:39:07 +00:00
parent 62a224defa
commit b915c39801
4 changed files with 104 additions and 84 deletions
Download Patch File Download Diff File Expand all files Collapse all files
Control/firmware/uart_echo/main.c
+3 -10
View File
@@ -13,6 +13,7 @@
#include <avr/wdt.h>
#include <avr/interrupt.h>
#include "machine.h"
#include "fifo.h"
#include "message.h"
#include "adc.h"
@@ -23,16 +24,8 @@
#include "mcp42x6.h"
#define PRINT(a,...) printf(a, ##__VA_ARGS__)
#define ARDUINO_NANO 1
#define PRINT_PROMPT putchar(0x0D);putchar(0x0A);putchar(':');
#if ARDUINO_NANO
#define F_CPU (16000000UL) // MHz
#else
#define F_CPU (18432000UL) // MHz
#endif
#define USART_BAUDRATE 9600UL
#define BAUD_PRESCALE (((F_CPU / (USART_BAUDRATE * 16UL))) - 1)
#define USART_BAUDRATE 115200UL
#define TIMER_HW_CLOCK (F_CPU/8)
#define TIMER_IRQ_CLOCK 1000UL
#define TIMER_HW_RELOAD (0xFFFF-(TIMER_HW_CLOCK/TIMER_IRQ_CLOCK))
@@ -96,7 +89,7 @@ int main(void)
fifo_init(&messageFifo, 8, sizeof(Msg_t), "Fifo");
/* Replace with your application code */
uart_init(&messageFifo, BAUD_PRESCALE);
uart_init(&messageFifo, USART_BAUDRATE);
timer_init(&messageFifo, TIMER_HW_RELOAD, TimerClockSel_PS_8);
adc_init(&messageFifo);
i2c_init();
Control/firmware/uart_echo/uart.c
+21 -3
View File
@@ -33,13 +33,31 @@ ISR(USART_RX_vect)
}
}
void uart_init(Fifo *pFifo, uint16_t BAUD_PRESCALE)
void uart_init(Fifo *pFifo, uint32_t baudrate)
{
g_pFifo = pFifo;
uint16_t prescale8 = UART_PRESCALE(baudrate, 8UL);
uint16_t prescale16 = UART_PRESCALE(baudrate, 16UL);
uint32_t baud8 = ((prescale8+1) * 8);
uint32_t baud16 = ((prescale16+1) * 16);
uint32_t err8 = abs(baudrate - baud8);
uint32_t err16 = abs(baudrate - baud16);
uint16_t prescale = prescale16;
if (err8 < err16)
{
prescale = prescale8;
// Double UART speed
UCSR0A |= 1 << U2X0;
}
// Set baud rate
UBRR0L = (uint8_t)BAUD_PRESCALE;
UBRR0H = (uint8_t)(BAUD_PRESCALE >> 8);
UBRR0L = (uint8_t)prescale;
UBRR0H = (uint8_t)(prescale >> 8);
// Enable receiver and transmitter
UCSR0B = (1<<TXEN0)|(1<<RXEN0);
Control/firmware/uart_echo/uart.h
+5 -1
View File
@@ -9,11 +9,15 @@
#ifndef UART_H_
#define UART_H_
#include "machine.h"
#include "fifo.h"
void uart_init(Fifo *pFifo, uint16_t BAUD_PRESCALE);
#define UART_PRESCALE(baudrate, smpPerBit) ((5+ 10*F_CPU / (baudrate*smpPerBit) - 1)/10)
void uart_init(Fifo *pFifo, uint32_t baudrate);
void uart_putc(char c);
int uart_putchar(char c, FILE *stream);
void uart_puts(char const *str);
#endif /* UART_H_ */
Control/firmware/uart_echo/uart_echo.cproj
+5
View File
@@ -95,6 +95,7 @@
<avrgcc.compiler.symbols.DefSymbols>
<ListValues>
<Value>NDEBUG</Value>
<Value>ARDUINO_NANO=1</Value>
</ListValues>
</avrgcc.compiler.symbols.DefSymbols>
<avrgcc.compiler.directories.IncludePaths>
@@ -134,6 +135,7 @@
<avrgcc.compiler.symbols.DefSymbols>
<ListValues>
<Value>DEBUG</Value>
<Value>ARDUINO_NANO=1</Value>
</ListValues>
</avrgcc.compiler.symbols.DefSymbols>
<avrgcc.compiler.directories.IncludePaths>
@@ -179,6 +181,9 @@
<Compile Include="i2c.h">
<SubType>compile</SubType>
</Compile>
<Compile Include="machine.h">
<SubType>compile</SubType>
</Compile>
<Compile Include="main.c">
<SubType>compile</SubType>
</Compile>