topic Re: LPC546xx: CT1_CAP0 on P2_0 doesn't work in LPC Microcontrollers

LPC546xx: CT1_CAP0 on P2_0 doesn't work

giusloq — Mon, 14 Mar 2022 12:05:22 GMT

I want to use P2_0 as the capture input 0 for CTIMER1, so, starting from lpcxpresso54628_hello_world SDK example for LPCXpresso EVB, I added the following code:

#define CTIMER CTIMER1 #define TIMER_RESOLUTION_ns 100 #if 0 #define PIN_CAPTURE 2, 0 #define CAPNUM 0 #define IOCON_PIO_FUNC4 4 #elif 1 #define PIN_CAPTURE 2, 17 #define CAPNUM 1 #define IOCON_PIO_FUNC4 4 #endif CLOCK_AttachClk(kMAIN_CLK_to_ASYNC_APB); IOCON_PinMuxSet(IOCON, PIN_CAPTURE, IOCON_PIO_FUNC4 | IOCON_PIO_MODE_INACT | /* No addition pin function */ IOCON_PIO_INV_DI | /* Input function is not inverted */ IOCON_PIO_DIGITAL_EN | /* Enables digital function */ IOCON_PIO_INPFILT_OFF | /* Input filter disabled */ IOCON_PIO_OPENDRAIN_DI); /* Open drain is disabled */ ctimer_config_t ctmr_cfg; ctmr_cfg.mode = kCTIMER_TimerMode; ctmr_cfg.prescale = (CLOCK_GetAsyncApbClkFreq() / 1000000) * TIMER_RESOLUTION_ns / 1000 - 1; CTIMER_Init(CTIMER, &ctmr_cfg); CTIMER_SetupCapture(CTIMER, kCTIMER_Capture_0 + CAPNUM, kCTIMER_Capture_BothEdge, true); /* Enable interrupt */ NVIC_EnableIRQ(CTIMER1_IRQn); CTIMER_StartTimer(CTIMER); void CTIMER1_IRQHandler(void) { CTIMER_ClearStatusFlags(CTIMER, CTIMER_IR_CR0INT_MASK << CAPNUM); }

P2_0 is on pin 8 of J12 Analog In connector on EVB. When I connect alternatively this pin to GND and VCC, no interrupt is fired.

When I try to use P2_17 as CT1_CAP1 (pin 20 of J13 Digital connector) it works, the interrupt is triggered.

What's wrong with P2_0? It's a type A pin, but it seems it can be used as CT1_CAP0.

Re: LPC546xx: CT1_CAP0 on P2_0 doesn't work

xiangjun_rong — Tue, 15 Mar 2022 02:52:02 GMT

Hi,

I have checked your code, I think you have to add the line:

CLOCK_EnableClock(kCLOCK_Iocon);

before you call the IOCON_PinMuxSet();

If you had added the line in your code, I have no idea, I think your code is correct. If you still can not fire the capture interrupt with P2_0 pin, pls try to configure the P2_0 as GPIO output mode, then set/clear the P2_0 pin, check the pin 8 of J12 Analog In connector on EVB, check if the state of the pin changes.

XiangJun Rong

Re: LPC546xx: CT1_CAP0 on P2_0 doesn't work

giusloq — Tue, 15 Mar 2022 09:21:14 GMT

I have checked your code, I think you have to add the line:
CLOCK_EnableClock(kCLOCK_Iocon);
before you call the IOCON_PinMuxSet();

Yes I have that code.

pls try to configure the P2_0 as GPIO output mode, then set/clear the P2_0 pin, check the pin 8 of J12 Analog In connector on EVB, check if the state of the pin changes.

I already made this test and it works.

Re: LPC546xx: CT1_CAP0 on P2_0 doesn't work

xiangjun_rong — Tue, 15 Mar 2022 10:06:29 GMT

Hi,

In the case, I have no idea, You have to use debugger to check the CTimer1 registers and the PIO2_0 register.

XiangJun Rong

Re: LPC546xx: CT1_CAP0 on P2_0 doesn't work

giusloq — Wed, 16 Mar 2022 09:48:00 GMT

In the case, I have no idea, You have to use debugger to check the CTimer1 registers and the PIO2_0 register.

Yes, I checked in Peripherals window of MCUXpresso and all the registers seem configured well.

Have you the possibility to check with one of your LPCXpresso54628 EVB and test a sample project to share with me? Many thanks.