Hello,
I've been starting to get into level 0.1 programming after being able to loosely control an LED with GPIOTE and a timer interrupt using examples and API references (copying code parts from the example)
And now I'm just trying to read data(With the simplest method of ACTUAL Serial interface using a Clock and a Data pin)
and for some reason after enabling the timer the while loop doesn't seems to want to exit despite the sanctification of the condition which as a beginner realy makes the vision over this platform distorted and difficult
Here's the code:
#include "nrf_drv_gpiote.h" //GPIOTE driver
#include "nrf_gpio.h"
#include "pca10040.h" //Pins mapping to meaningful macroas for the nRF52840-DK (aka pca10056)
#include "nrf_drv_timer.h"
#define CLK_PIN 24
#define DT_PIN 25
#define GAIN 1
int Data = 0;
int BitPos = 27;
void timer0_event_handler(nrf_timer_event_t event_type, void *p_context){
Data << 1;
nrf_gpio_pin_set(CLK_PIN);
Data |= nrf_gpio_pin_read(DT_PIN);
nrf_gpio_pin_clear(CLK_PIN);
BitPos++;
}
//create a constant variable of type struct nrf_drv_timer_t and initialize it with the desired TIMER number(0-5 for nRF52840) to use.
const nrf_drv_timer_t TIMER0_INS = NRF_DRV_TIMER_INSTANCE(0);
int main(void)
{
uint32_t time_us = 1; //Time(in miliseconds) between consecutive compare events.
uint32_t time_ticks; // converted time in ticks to set the capture register of the timer.
nrf_gpio_cfg_input(DT_PIN, NRF_GPIO_PIN_NOSENSE);
nrf_gpio_cfg_output(CLK_PIN);
//Create a variable of type struct nrf_drv_timer_config_t and initialize this variable to NRF_DRV_TIMER_DEFAULT_CONFIG.
nrf_drv_timer_config_t timer_cfg = NRF_DRV_TIMER_DEFAULT_CONFIG;
//Set timer bit width to 32 bit <3> instead of the default 16 bit for better timer resolution.
timer_cfg.bit_width = 3;
/*Setup GPIOTE*/
nrf_drv_timer_init(&TIMER0_INS, &timer_cfg, timer0_event_handler);
time_ticks = nrf_drv_timer_us_to_ticks(&TIMER0_INS, time_us);
//set the timer comare/capture in extended compare mode, which means it will keep triggering indefinitely
//NRF_TIMER_SHORT_COMPARE0_CLEAR_MASK is a shortcut to clear the timer after compare0 is triggered
nrf_drv_timer_extended_compare(&TIMER0_INS, NRF_TIMER_CC_CHANNEL0, time_ticks, NRF_TIMER_SHORT_COMPARE0_CLEAR_MASK, true);
nrf_gpio_pin_clear(CLK_PIN);
for(int c = 0;c <= 25; c++)
{
nrf_gpio_pin_set(CLK_PIN);
nrf_gpio_pin_clear(CLK_PIN);
}
nrf_drv_timer_enable(&TIMER0_INS);
while(BitPos <= 24){
}
BitPos = 0;
nrf_drv_timer_disable(&TIMER0_INS);
while (true)
{
/*Enter sleep, more on sleep modes in Lesson 14 */
__SEV();
__WFE();
__WFE();
}
}
Also pretty sure what ever I tried there to read that 24 bit data from that HX711 is not the proper way(using timer and all that salad there) but can't get to my mind how to do this otherwise sins the main clock frequency is realy too high for purely pulsing the clock signal the HX711 needs and in arduino you'd just write the shiftIn() function but here I have no idea of even how to look for it sins example API are rare and not that clear, and it'd take ages to scan the nordic info center documentation for that, so If there is a simpler method to read Serial data I'd be highly appreciated.
thanks for helping!
