Measuring input from a reed switch with STM32L100RB

[idris]

Posted on October 02, 2015 at 17:08

I want to count pulses generated from a reed switch. The switch has three outputs connected to WKUP1, WKUP2 and PCO of the STM32L100RB. I need an example or suggestions on how to achieve this. Kindly assist.

[Tesla DeLorean]

Posted on October 02, 2015 at 19:36

Take a look at the EXTI examples where the pins could generate interrupts. Might need to consider debouncing

STM32L1xx_StdPeriph_Lib_V1.2.0\Project\STM32L1xx_StdPeriph_Examples\EXTI\EXTI_Example\main.c

[idris]

Posted on October 05, 2015 at 09:46

Thanks Clive1.

[idris]

Posted on October 05, 2015 at 09:56

Hi Clive1,

Kindly send me the link to the V1.2.0 Library. I can only find the latest version i.e. V1.3.1.

[Tesla DeLorean]

Posted on October 05, 2015 at 18:29

Pretty sure the newer version has the same examples, I just went through the most recent library I had unpacked.

[idris]

Posted on January 21, 2016 at 13:59

Hello Clive1,

Please see the attachment for my implementation. I set up two interrupts for the signal lines. One on GPIO PA0 connected to EXTI_Line0. The second on GPIO PC13 connected to EXTI_Line However, the first interrupt is working fine, but the second isn't. I want to be able to get input from both signal lines. how can I achieve this?

________________

Attachments :

Switch_Interrupt_Implementation.docx : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006I0Tm&d=%2Fa%2F0X0000000biD%2F60tvLLytkJ8zmjsOqI5cYTAJbucx465frvnpUExwYOc&asPdf=false

[Tesla DeLorean]

Posted on January 21, 2016 at 18:29

Probably want a more complete/consistent use of defines, or create a pin structure holding all the details,

void EXTI15_10_IRQHandler(void) {
if (EXTI_GetITStatus(EXTI_Line13) != RESET) {
if (GPIO_ReadOutputDataBit(GPIOA, GPIO_Pin_9)) // <<< SURELY THIS SHOULD BE PC.13 ???
{
GPIO_ResetBits(GPIOA, GPIO_Pin_9);
delay (500);
GPIO_SetBits(GPIOA, GPIO_Pin_9);
delay (500);
}
EXTI_ClearITPendingBit(EXTI_Line13);
} 
}

[idris]

Posted on January 23, 2016 at 17:01

Thanks Clive1. I did make the adjustment but still no response. Do I need to include EXTI_GenerateSWInterrupt(EXTI_Line13) in the main?

[Tesla DeLorean]

Posted on January 23, 2016 at 18:21

And have we confirmed that the GPIOs transition as expected if you just loop polling the pins, and outputting via LEDs?