Hi everyone,
I am trying to make work a stepper motor by Bluetooth with a nrf51822, Actually it is working, the motor turn, but the thing is I Don't know how to control the number or rotation it makes precisely.
I am using a stepper motor (www.pololu.com/.../2267, this stepper motor) it takes 200 steps so make a full rotation.
What I do in the code is this :
first I receive a data from the Bluetooth app that send on to turn in one side and off to turn in the other side, I also receive a number that is use as a counter to control the time it should turn :
static void nus_data_handler(ble_nus_t * p_nus, uint8_t * p_data, uint16_t length)
{
char on[2] = "on";
char off[3] = "off";
for (uint32_t i = 0; i < length; i++)
{
while (app_uart_put(p_data[i]) != NRF_SUCCESS);
}
while (app_uart_put('\r') != NRF_SUCCESS);
while (app_uart_put('\n') != NRF_SUCCESS);
//uint8_t param[6] = (char*)p_data;
ble_nus_string_send(&m_nus, (char*)p_data, strlen((char*)p_data));
char *ret;
const char esc = '/';
ret = strchr((char*)(p_data),esc);
memmove(ret, ret+1, strlen(ret));
ble_nus_string_send(&m_nus, ret, strlen((char*)ret));
char *ptr;
if(strstr((char*)(p_data), on)){
nrf_gpio_pin_set(sleepPin);
nrf_gpio_pin_clear(LED3);
//use to controle the number of rotation it makes
steps_left = strtol(ret, &ptr, 10);
Direction=true;
uint8_t close[5] = "close";
ble_nus_string_send(&m_nus, close, strlen((char*)close));
}
if(strstr((char*)(p_data), off)){
nrf_gpio_pin_set(sleepPin);
nrf_gpio_pin_set(LED3);
//use to controle the number of rotation it makes
steps_left = strtol(ret, &ptr, 10);
Direction=false;
uint8_t open[4] = "open";
ble_nus_string_send(&m_nus, open, strlen((char*)open));
}
}
Then I have a function that makes rotate the motor and that set the direction :
I use APP_TIMER_TICKS as a counter, I have set correctly all the things related to this function I think, I followed the app_timer tutorial.
void stepper(){
uint32_t err_code;
uint32_t err_code2;
if(Direction == true){
nrf_gpio_pin_set(dirPin);
}else{
nrf_gpio_pin_clear(dirPin);
}
err_code = app_timer_start(timer_step, APP_TIMER_TICKS(1 , APP_TIMER_PRESCALER), NULL);
APP_ERROR_CHECK(err_code);
}int main(void)
{
uint32_t err_code;
bool erase_bonds;
// Initialize.
APP_TIMER_INIT(APP_TIMER_PRESCALER, APP_TIMER_OP_QUEUE_SIZE, false);
uart_init();
buttons_leds_init(&erase_bonds);
ble_stack_init();
gap_params_init();
services_init();
advertising_init();
conn_params_init();
printf("\r\nUART Start!\r\n");
err_code = ble_advertising_start(BLE_ADV_MODE_FAST);
APP_ERROR_CHECK(err_code);
create_timers();
nrf_gpio_pin_dir_set(stepPin, NRF_GPIO_PIN_DIR_OUTPUT);
nrf_gpio_pin_dir_set(dirPin, NRF_GPIO_PIN_DIR_OUTPUT);
nrf_gpio_pin_dir_set(sleepPin, NRF_GPIO_PIN_DIR_OUTPUT);
nrf_gpio_pin_dir_set(MS1, NRF_GPIO_PIN_DIR_OUTPUT);
nrf_gpio_pin_dir_set(MS2, NRF_GPIO_PIN_DIR_OUTPUT);
// Enter main loop.
for (;;)
{
nrf_gpio_pin_clear(MS1);
nrf_gpio_pin_clear(MS2);
//nrf_gpio_pin_set(stepPin);
if(steps_left != 0){
stepper();
steps_left--;
if(steps_left == 0){
nrf_gpio_pin_clear(sleepPin);
nrf_gpio_pin_clear(stepPin);
nrf_gpio_pin_clear(dirPin);
err_code = app_timer_stop_all();
uint8_t step0[5] = "step0";
ble_nus_string_send(&m_nus, step0, strlen((char*)step0));
}
}
power_manage();
}
}
