Acceleration active and deactivate GPS

[Hoang]

Dear, 

Im trying to use the motion to activate the GPS and deactivate GPS:

    1. when it moves, GPS will be activated: Position-ON 

   2. when it stops, GPS will be activated again: Position-OFF

Currently, I used the sensor_trigger_set() to enable GPS when it detects the motion as in :https://github.com/NordicPlayground/fw-nrfconnect-nrf/tree/master/applications/asset_tracker

But, I dont know how to implement the step 2:  when it stops, GPS will be activated again: Position-OFF

Could you plz help me, thanks so much 

My HW: THINGY:91 

Modem FW: v1.1.1

ncs_1.2.0

BR, 

Hoang Ng

[Håkon Alseth]

Hi,

 

But, I dont know how to implement the step 2:  when it stops, GPS will be activated again: Position-OFF

Do you want to stop the GPS, or start it again? These two functions enable/disable the gps_controller library: https://github.com/NordicPlayground/fw-nrfconnect-nrf/blob/master/applications/asset_tracker/src/gps_controller/gps_controller.c#L125-L133

 

If you're using asset_tracker, as-is, you can also look at this function:

https://github.com/NordicPlayground/fw-nrfconnect-nrf/blob/master/applications/asset_tracker/src/main.c#L1221

 

Kind regards,

Håkon

[Hoang]

Håkon Alseth said:

Do you want to stop the GPS, or start it again? These two functions enable/disable the gps_controller

I want to start GPS again. For example, my thingy:91 is staying in my car, when the car is moving: start GPS and capture the start-Position, then stop GPS. When the car stops, start GPS again, and capture the stop-Position. During the moving time of the car, the THINGY:91 will sleep (to save the power), it just captures 2 positions: start and stop position. 

[Håkon Alseth]

Hi,

 

You are asserting because a kernel function is called from interrupt context. Try setting a flag and handle it in main, or push the work to a workqueue instead.

Note that all socket operations will trigger an interrupt to communicate with the modem, so no socket functions should be called from an interrupt.

 

Kind regards,

Håkon

[Hoang]

Thank Håkon Alseth, 

I will read and try to understand your guide. Thanks a lot ( Sorry, I don't have knowledge about programming )

BR, 

Hoang Nguyen

[Håkon Alseth]

Hi Hoang,

 

Its not stated directly that you shouldn't call socket operations directly from interrupt, nor that the kernel timers are executed in interrupt context, and we should document this a bit better. I'll write it down as a improvement and report it internally.

 

Kind regards,

Håkon

[Hoang]

Hi Håkon Alseth, 

in the timer.zip 

#define TIMEOUT 60000 //milisecond 

static u32_t timestamp_prev;
int counter ;
bool gps_enable_timeout; 

nrfx_timer_t my_timer = NRFX_TIMER_INSTANCE(0);
nrfx_timer_config_t my_timer_config = NRFX_TIMER_DEFAULT_CONFIG;

void timer_cb(nrf_timer_event_t event_type, void * p_context) {
    
    timestamp_prev = k_uptime_get_32();
    counter += 1;
    printk("counter: %d \r",counter);
    printk("timestamp_prev: %d \n\r",timestamp_prev); 
    printk("set_gps_enable----------\r");
    printk("start GPS ..\n");
    set_gps_enable(true);
    gps_enable_timeout = true ; 

    printk("gps_enable_timeout: %d \n\r", gps_enable_timeout); 
}

void main() {

    printk("Timer sample started\n");
    counter = 0; 
    gps_enable_timeout = false; 

    IRQ_CONNECT(DT_NORDIC_NRF_TIMER_TIMER_0_IRQ_0, 
                DT_NORDIC_NRF_TIMER_TIMER_0_IRQ_0_PRIORITY, 
                nrfx_isr, 
                nrfx_timer_0_irq_handler, 
                0);


    my_timer_config.frequency = NRF_TIMER_FREQ_31250Hz;
    
    nrfx_err_t err = nrfx_timer_init(&my_timer, &my_timer_config, timer_cb);
    if (err != NRFX_SUCCESS) {
        printk("timer_init error: %d\n", err);
        return;
    }

    // Set the timer to trigger every second.
    
      uint32_t time_ticks = nrfx_timer_ms_to_ticks(&my_timer, TIMEOUT);
      printk("Setting compare, timeout after %d ticks\n", time_ticks ); 
    
  // nrfx_timer_compare(&my_timer, NRF_TIMER_CC_CHANNEL0, nrfx_timer_ms_to_ticks(&my_timer, TIMEOUT), true);
     nrfx_timer_compare(&my_timer, NRF_TIMER_CC_CHANNEL0,time_ticks, true);
   
    
     printk("Starting timer\n");
     nrfx_timer_enable(&my_timer);
    
     printk("Timer started\n");
    
    
}

I changed the TIMEOUT to 60000 (miliseconds), I expected the timer will "trigger" after TIMEOUT 

But, it always trigger after 1s. 

I check the document:  https://infocenter.nordicsemi.com/index.jsp?topic=%2Fsdk_nrf5_v16.0.0%2Fgroup__nrfx__timer.html&cp=7_1_6_9_0_37_1_10&anchor=ga949efcc263af88d63ecdce7eaa3d5761

Did I misunderstand somewhere? 

Thanks, 

Best Regards, 

Hoang

[Håkon Alseth]

Hi Hoang,

 

Can this be your issue? The timer is by default 16 bit, so it will not be able to count as long as 60 secs:

https://infocenter.nordicsemi.com/topic/ps_nrf9160/timer.html?cp=2_0_0_5_15_4_18#register.BITMODE

 

You can use the kernel timer API as well, since you already have the "schedule to main" functionality implemented.

https://docs.zephyrproject.org/1.12.0/kernel/timing/timers.html#defining-a-timer

 

To get it reoccurring, remember to add this to the _start function call:

k_timer_start(&my_sync_timer, K_SECONDS(10), K_SECONDS(10);
 
Kind regards,
Håkon