EMTime/libopencm3-examples
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

f3:i2c: use printf and update docs

Browse Source 
Preparations for updating the tree was making sure the existing example
worked :)
This commit is contained in:
Karl Palsson
2017-09-01 23:01:56 +00:00
parent 2107faf5ee
commit d6876b1f77
2 changed files with 24 additions and 28 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
examples/stm32/f3/stm32f3-discovery/i2c/README.md
View File

@@ -1,5 +1,8 @@
# README # README
I2C example reading from the stm32f3discovery accelerometer. UART TX on PA2 @ 115200/8n1
This example reads the onboard accelerometer and dumps the raw value
of the ACC_OUT_X_L_A/ACC_OUT_X_H_A registers. (you should see ~0 for flat,
and positive/negative values for tipping the board along it's long axis,
ranging up to plus/minus 16k or so for vertical.

45
examples/stm32/f3/stm32f3-discovery/i2c/i2c.c
View File

@@ -20,6 +20,8 @@
* along with this library. If not, see <http://www.gnu.org/licenses/>. * along with this library. If not, see <http://www.gnu.org/licenses/>.
*/ */
#include <errno.h>
#include <stdio.h>
#include <libopencm3/stm32/rcc.h> #include <libopencm3/stm32/rcc.h>
#include <libopencm3/stm32/usart.h> #include <libopencm3/stm32/usart.h>
#include <libopencm3/stm32/i2c.h> #include <libopencm3/stm32/i2c.h>
@@ -97,34 +99,24 @@ static void gpio_setup(void)
GPIO14 | GPIO15); GPIO14 | GPIO15);
} }
static void my_usart_print_int(uint32_t usart, int32_t value) int _write(int file, char *ptr, int len)
{ {
int8_t i; int i;
int8_t nr_digits = 0;
char buffer[25];
if (value < 0) { if (file == 1) {
usart_send_blocking(usart, '-'); for (i = 0; i < len; i++) {
value = value * -1; if (ptr[i] == '\n') {
} usart_send_blocking(USART2, '\r');
}
if (value == 0) { usart_send_blocking(USART2, ptr[i]);
usart_send_blocking(usart, '0'); }
} return i;
}
while (value > 0) { errno = EIO;
buffer[nr_digits++] = "0123456789"[value % 10]; return -1;
value /= 10;
}
for (i = nr_digits-1; i >= 0; i--) {
usart_send_blocking(usart, buffer[i]);
}
usart_send_blocking(usart, '\r');
usart_send_blocking(usart, '\n');
} }
static void clock_setup(void) static void clock_setup(void)
{ {
rcc_clock_setup_hsi(&rcc_hsi_8mhz[RCC_CLOCK_64MHZ]); rcc_clock_setup_hsi(&rcc_hsi_8mhz[RCC_CLOCK_64MHZ]);
@@ -150,13 +142,14 @@ int main(void)
clock_setup(); clock_setup();
gpio_setup(); gpio_setup();
usart_setup(); usart_setup();
printf("Hello, we're running\n");
i2c_setup(); i2c_setup();
/*uint8_t data[1]={(0x4 << ACC_CTRL_REG1_A_ODR_SHIFT) | ACC_CTRL_REG1_A_XEN};*/ /*uint8_t data[1]={(0x4 << ACC_CTRL_REG1_A_ODR_SHIFT) | ACC_CTRL_REG1_A_XEN};*/
uint8_t data[1]={0x97}; uint8_t data[1]={0x97};
write_i2c(I2C1, I2C_ACC_ADDR, ACC_CTRL_REG1_A, 1, data); write_i2c(I2C1, I2C_ACC_ADDR, ACC_CTRL_REG1_A, 1, data);
data[0]=0x08; data[0]=0x08;
write_i2c(I2C1, I2C_ACC_ADDR, ACC_CTRL_REG4_A, 1, data); write_i2c(I2C1, I2C_ACC_ADDR, ACC_CTRL_REG4_A, 1, data);
uint16_t acc_x; int16_t acc_x;
while (1) { while (1) {
@@ -166,7 +159,7 @@ int main(void)
acc_x=data[0]; acc_x=data[0];
read_i2c(I2C1, I2C_ACC_ADDR, ACC_OUT_X_H_A, 1, data); read_i2c(I2C1, I2C_ACC_ADDR, ACC_OUT_X_H_A, 1, data);
acc_x|=(data[0] << 8); acc_x|=(data[0] << 8);
my_usart_print_int(USART2, (int16_t) acc_x); printf("data was %d\n", acc_x);
//int i; //int i;
//for (i = 0; i < 800000; i++) /* Wait a bit. */ //for (i = 0; i < 800000; i++) /* Wait a bit. */
// __asm__("nop"); // __asm__("nop");