This file contains an example on how to use the TWI driver library. It sets up the TWI in master mode. Depending on the global definitions READ and WRITE, it will try to read and write data to a TWI slave. See documentation or comments in this file for further information
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Definition in file twi_example.c.
#include "twi.h"
Go to the source code of this file.
Defines | |
| #define | CPU_HZ 20000000 |
| #define | ERROR -1 |
| #define | READ 0 |
| #define | SUCCESS 0 |
| #define | WRITE 0 |
Typedefs | |
| typedef unsigned char | avr32_piomap_t [][2] |
Functions | |
| int | main (void) |
| int | pio_enable_module (avr32_piomap_t piomap, unsigned int size) |
| Set the pins under module control. | |
| #define CPU_HZ 20000000 |
| #define ERROR -1 |
| #define READ 0 |
| #define SUCCESS 0 |
| #define WRITE 0 |
| typedef unsigned char avr32_piomap_t[][2] |
Definition at line 83 of file twi_example.c.
| int main | ( | void | ) |
Definition at line 89 of file twi_example.c.
References twi_package_t::addr, twi_package_t::addr_length, twi_package_t::buffer, twi_package_t::chip, CPU_HZ, twi_options_t::cpu_hz, ERROR, twi_package_t::length, pio_enable_module(), READ, twi_options_t::speed, SUCCESS, twi_options_t::twi_addr, twi_init(), twi_read(), TWI_SUCCESS, twi_write(), and WRITE.
00090 { 00091 struct twi_options_t opt; 00092 struct twi_package_t package; 00093 00094 int bytes; 00095 char buf_out[32] = "testing_testing\0"; 00096 char buf_in[32]; 00097 00098 00099 avr32_piomap_t twi_piomap = { \ 00100 {AVR32_TWI_SCL_0_PIN, AVR32_TWI_SCL_0_FUNCTION}, \ 00101 {AVR32_TWI_SDA_0_PIN, AVR32_TWI_SDA_0_FUNCTION} \ 00102 }; 00103 00104 pio_enable_module(twi_piomap, 2); 00105 00106 // TWI - 200kpbs, own address 0x42 (NOT USED) 00107 opt.cpu_hz = CPU_HZ; 00108 opt.speed = 200000; 00109 opt.twi_addr = 0x42; 00110 00111 if( twi_init(&opt) != TWI_SUCCESS ) 00112 return ERROR; 00113 00114 /* master write */ 00115 if (WRITE){ 00116 package.chip = 0x34; // Chip address for receiver 00117 package.addr = package.chip; // Address/command within the remote device 00118 package.addr_length = 0; // Address/command length in bytes 00119 package.length = 4; // Number of bytes in the data package 00120 package.buffer = buf_out; // The data package itself 00121 00122 bytes = twi_write(&package); 00123 if(bytes != package.length) 00124 return ERROR; 00125 } 00126 00127 /* master read */ 00128 if (READ){ 00129 package.chip = 0x34; // Chip address for receiver 00130 package.addr = package.chip; // Address/command within the remote device 00131 package.addr_length = 0; // Address/command length in bytes 00132 package.length = 13; // Number of bytes in the data package 00133 package.buffer = buf_in; // The data package itself 00134 00135 bytes = twi_read(&package); 00136 if(bytes != package.length) 00137 return ERROR; 00138 } 00139 00140 return SUCCESS; 00141 }
| int pio_enable_module | ( | avr32_piomap_t | piomap, | |
| unsigned int | size | |||
| ) |
Set the pins under module control.
| piomap | a map describing how the setup of the PIO | |
| size | number of elements in the map |
| SUCCESS | on success | |
| ERROR | on bad values in piomap |
Definition at line 153 of file twi_example.c.
References ERROR, and SUCCESS.
Referenced by main().
00154 { 00155 int i; 00156 volatile struct avr32_pio_t *pio; 00157 00158 /* get the base address for the port */ 00159 switch (**piomap/32) { 00160 00161 case 0: 00162 pio = &AVR32_PIOA; 00163 break; 00164 case 1: 00165 pio = &AVR32_PIOB; 00166 break; 00167 case 2: 00168 pio = &AVR32_PIOC; 00169 break; 00170 case 3: 00171 pio = &AVR32_PIOD; 00172 break; 00173 case 4: 00174 pio = &AVR32_PIOE; 00175 break; 00176 default : 00177 return ERROR; 00178 00179 } 00180 00181 for(i=0; i<size; i++){ 00182 00183 pio->pdr |= ( 1<<( (**piomap) % 32) ); 00184 pio->pudr |= ( 1<<( (**piomap) % 32) ); 00185 00186 switch( *(*piomap+1) ){ 00187 case 0: 00188 pio->asr |= ( 1<<( (**piomap) % 32) ); 00189 break; 00190 case 1: 00191 pio->bsr |= ( 1<<( (**piomap) % 32) ); 00192 break; 00193 default: 00194 return ERROR; 00195 } 00196 00197 ++piomap; 00198 00199 } 00200 00201 return SUCCESS; 00202 }
1.5.3