Strange behavior Button 2 and Button 3 on nRF51 DK

RE: Strange behavior Button 2 and Button 3 on nRF51 DK

Øyvind Karlsen — Fri, 15 Jul 2016 06:07:51 GMT

You can use the port event from GPIOTE to trigger an interrupt, then handle that interrupt and evaluate current GPIO state.

For the nrf_drv_gpiote_in_init I think you might be right, when I was debugging it seemed to change behaviour of the code, but it might have been a coincidence.

RE: Strange behavior Button 2 and Button 3 on nRF51 DK

Hieu — Fri, 15 Jul 2016 04:44:48 GMT

First of all, those wrong flags are exactly the problem. I kept looking elsewhere for the issue while it is such a fundamental one. Many apologies.

I used GPIOTE simply because that was the only way I found to get an event upon GPIO change. I tried looking into the GPIO peripheral driver, but all I could find was setting up a GPIO as input, not setting up an interrupt for that. I think I simply haven't found the right way to do things yet. You seem to imply that there is a better way to do this. Could you point me to where I could find a better way to do this? I would be glad to learn.

Finally, regarding clearing pending interrupt, to my understanding, because I am using nrf_drv_gpiote_in_init() to assign a handler, the driver would automatically clear the pending interrupt before calling my handler. Could I have misunderstood this as well?

RE: Strange behavior Button 2 and Button 3 on nRF51 DK

Øyvind Karlsen — Thu, 14 Jul 2016 09:22:11 GMT

I didn't quite get why you were using GPIOTE, either way you need to clear the pending interrupt at the start of each interrupt handler. For example by calling NVIC_ClearPendingIRQ(GPIOTE_IRQn);. Otherwise the interrupt will call itself again and again.

You were also setting the wrong flags to false, change to the code below.

#if DEV_CFG_USE_FLAG
        if (m_group1_input_it_flag)
        {
            nrf_gpio_pin_toggle(GROUP1_OUTPUT1_PIN);
            nrf_gpio_pin_toggle(GROUP1_OUTPUT2_PIN);
            
            m_group1_input_it_flag = false;
        }
        if (m_group2_input_it_flag)
        {
            nrf_gpio_pin_toggle(GROUP2_OUTPUT1_PIN);
            nrf_gpio_pin_toggle(GROUP2_OUTPUT2_PIN);
            
            m_group2_input_it_flag = false; //Change this
        }
        if (m_group3_input_it_flag)
        {
            nrf_gpio_pin_toggle(GROUP3_OUTPUT1_PIN);
            nrf_gpio_pin_toggle(GROUP3_OUTPUT2_PIN);
            
            m_group3_input_it_flag = false; //Change this
        }
#endif // #if DEV_CFG_USE_FLAG

Be aware that there is a limit on the maximum low power resources, this can be changed in the file nrf_drv_config, found in ble_app_uart\config.

RE: Strange behavior Button 2 and Button 3 on nRF51 DK

Hieu — Thu, 14 Jul 2016 02:50:13 GMT

I thought I replied last week already but it turns out I didn't. I probably forgot to hit the add comment button or something. Sorry about this. The reason is because I often need to run a fair amount of work at a GPIO event, not just a couple of GPIO toggling like this. Meanwhile, I believe I should avoid running large amount of code in the interrupt context (unless there is some difference thanks to nRF's PPI system?). That is why I often use the flag raising strategy, sacrificing a little response time for safety. Therefore I would like to find the root of the problem to avoid issues in the future.

But you are right that for my current particular case, I could just run the simple GPIO toggling in the handler.

RE: Strange behavior Button 2 and Button 3 on nRF51 DK

Øyvind Karlsen — Tue, 05 Jul 2016 06:58:04 GMT

If its working without the flag implementation, why not stick with that?

RE: Strange behavior Button 2 and Button 3 on nRF51 DK

Hieu — Thu, 30 Jun 2016 10:06:08 GMT

Just updated the question with a better edited main.c and the modified pca10028.h I used for your convenience.

RE: Strange behavior Button 2 and Button 3 on nRF51 DK

Hieu — Thu, 30 Jun 2016 09:36:05 GMT

Sorry Øyvind, I missed those when I trimmed out the unrelevant part. Another thing I forgot is enable the flag macro. If you change DEV_CFG_USE_FLAG to 1 it should enable using flag instead of using handler directly. DEV_CFG_USE_BSP on the other hand enable and disable BSP feature

RE: Strange behavior Button 2 and Button 3 on nRF51 DK

Øyvind Karlsen — Thu, 30 Jun 2016 09:19:04 GMT

Hi,

Had to include some .h files and comment out ir_raw.h. When I compiled and ran it LED 1, 2 and 3 on the DK lit up, and these become unlit when I hold Button 1, 2 and 3 respectively. I am also able to connect to it using master control panel on a android device. None of the LEDs are blinking by themselves in either connected or advertising mode.

RE: Strange behavior Button 2 and Button 3 on nRF51 DK

Hieu — Thu, 30 Jun 2016 08:26:05 GMT

Øyvind, I think my problem is a little different. What I am seeing is that after pressing button 2 or 3, pressing any button (1, 2 or 3) will cause button 2 or 3's flagged routine to run. For example, after pressing button 2, when I pressed button 1 I will see both LED 1 and 2 blink.

You could check that out with my attached main.c. It should work by just replacing it into an ble_app_uart example of SDK v10.

I would like to understand the root of this problem a little better for future use of GPIO interrupt and flags, since I foresee a need to run a heavy workload at an GPIO event.

RE: Strange behavior Button 2 and Button 3 on nRF51 DK

Øyvind Karlsen — Tue, 28 Jun 2016 07:54:17 GMT

Setting the LEDs in main might get tangled up in interrupts that occur at the same time. Since it works in the handler and not in main I guess this is what you are seeing.

If what you want to do is to toggle LEDs every time you press a button you can follow the BSP tutorial, as it implements this.

RE: Strange behavior Button 2 and Button 3 on nRF51 DK

Hieu — Tue, 28 Jun 2016 07:41:31 GMT

Øyvind,

I tried a little more without BSP, and has observed that even without BSP, using nRF51 Button 2 and 3 along with flag raising still cause events to be tangled up with each other. Do you have any guess what is going on?

RE: Strange behavior Button 2 and Button 3 on nRF51 DK

Øyvind Karlsen — Mon, 27 Jun 2016 09:05:42 GMT

Hi,

I've also had trouble with unexpected behavior when running BSP and BLE simultaneously. What happens is that the function bsp_led_indication() in bsp.c will turn off all LEDs and then blink LED1.

LEDS_OFF(LEDS_MASK & ~BSP_LED_0_MASK & ~m_alert_mask);

// in advertising blink LED_0
if (LED_IS_ON(BSP_LED_0_MASK))
{
    LEDS_OFF(BSP_LED_0_MASK);
    next_delay = indicate == BSP_INDICATE_ADVERTISING ? ADVERTISING_LED_OFF_INTERVAL : ADVERTISING_SLOW_LED_OFF_INTERVAL;
}

You can comment out the line LEDS_OFF line. For me the BSP is too much of an abstraction and I prefer to implement buttons and LEDs myself to have full control over what is happening.

Best regards,

Øyvind