Fail to handle interruption

[Edgar]

Hello,

I've a problem with handling interruption on nrf51dk (SDK12.1.0). I set GPIOTE to handle interruption based on the example code "pin_change_int". I work with the gyroscope of a LSM9DS0 sensor who generate interruption after a specified amount of measure.

When i flash the nrf51dk with my soft and connect the wire to the pin i configure to handle the interruption all work fine (i have a led who blink if an interruption is handle). But if i reset the nrf51dk with the reset button and with the wire already connect i handle no interruption. (idem with re-flashing the nrf51 or if i shutdown/poweron). In this situation if i unplug and replug the wire all work fine and the interruption is handle.

I have do some electric test:

• When the wire are not plug i have around 0V on the pin
• When i start the nrf51 with wire pluged i have around 2,7V on the pin
• When i plug the wire (the interrupt was handle) i have a value who varied between 0,7 and 0,9V (because the sensor generate a lot of interruption i think).

So... Someone have an idea on why it doesn't work when plugged at start ?

Thanks

[Ole Bauck]

What is the gpiote pin config (nrf_drv_gpiote_in_config_t)?

[Edgar]

The gpiote pin config was initialized with GPIOTE_CONFIG_IN_SENSE_TOGGLE(true) and "pull" attribute was set to NRF_GPIO_PIN_PULLDOWN

[Ole Bauck]

You should not need the pull down resistor as the sensor should drive the line between 0V and Vdd, but I don't think that is the problem.

I guess you cannot go into debug mode, as the pin reset will not be the same, but you should in some way check if the GPIOTE_IRQHandler is called at all after the reset. Check what the PIN_CNF register of the gpio pin you use is.

It is hard to know what the problem is from the information given.

[Edgar]

Thanks, i will try to check that. And try to use the same system with another sensor to see if i have the same issue. I can't do this now so i will try latter and come back here to post some news on my issue.