Hello,
I am using the mentioned controlCARD for my application for which I have designed my own Docking Station. In this docking station I use a switch connected to the pin 33 of the DIMM100 connector to use it as an input peripheral. If the controlCARD is not connected, the switch works fine, with a value close to 0 V when in the OFF position and close to 3 V when if in the ON position.
The problem comes when I plug the controlCARD in the DIMM100 connector, because then the value, when it is in OFF position, becomes 2.5 V. I have 4 more switches using GPIO11,13,30 and 31 and all of them work perfectly, so I decided to test the controlCARD itself because in the schematics I do not see any connection between the PB4_GPIO12 and anything else but the DIMM100 connector.
If I power the controlCARD with the microUSB connector at the top of the board and measure the voltage of pin 33 (GPIO12) of the DIMM100 connector and pin 8 (GND) the voltage is again 2.5 V, and if I check the resistance (without powering the board) between the pin 33 and ground and pin 33 and this 5 V point both result in approximately 2 KOhm.
I do not think it is a software problem because it does not happen with other GPIOs, but just in case I include my M3 code, which is written to the flash memory:
#include "inc/hw_sysctl.h"
#include "inc/hw_ints.h"
#include "inc/hw_memmap.h"
#include "inc/hw_nvic.h"
#include "inc/hw_types.h"
#include "inc/hw_gpio.h"
#include "driverlib/ipc.h"
#include "driverlib/sysctl.h"
#include "driverlib/interrupt.h"
#include "driverlib/debug.h"
#include "driverlib/cpu.c"
#include "driverlib/gpio.h"
void main(void)
{
volatile int i = 0;
// Allow writes to protected registers.
HWREG(SYSCTL_MWRALLOW) = 0xA5A5A5A5;
// Sets up PLL, M3 running at 75MHz and C28 running at 150MHz
SysCtlClockConfigSet(SYSCTL_USE_PLL | (SYSCTL_SPLLIMULT_M & 0xF) | SYSCTL_SYSDIV_1 | SYSCTL_M3SSDIV_2 | SYSCTL_XCLKDIV_4);
// Enable all GPIOs
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOB);
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOC);
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOD);
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOE);
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOF);
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOG);
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOH);
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOJ);
// Unlock the register to change the commit register value for Port B Pin 7
// This disables the NMI functionality on the pin and allows other muxing options to be used
HWREG(GPIO_PORTB_BASE+GPIO_O_LOCK) = GPIO_LOCK_KEY_DD;
// Write to commit register
HWREG(GPIO_PORTB_BASE+GPIO_O_CR) |= 0x000000FF;
// Delay
for (i=0;i<20;i++){};
// Enable Pull-ups on EPWM(1-8)A/B capable pins
GPIOPadConfigSet(GPIO_PORTA_BASE, 0xFF, GPIO_PIN_TYPE_STD_WPU);
GPIOPadConfigSet(GPIO_PORTB_BASE, 0x00, GPIO_PIN_TYPE_STD_WPU);
GPIOPadConfigSet(GPIO_PORTD_BASE, 0xB9, GPIO_PIN_TYPE_STD_WPU);
GPIOPadConfigSet(GPIO_PORTE_BASE, 0x00, GPIO_PIN_TYPE_STD_WPU);
// Give C28 control of all GPIOs
GPIOPinConfigureCoreSelect(GPIO_PORTA_BASE, 0xFF, GPIO_PIN_C_CORE_SELECT);
GPIOPinConfigureCoreSelect(GPIO_PORTB_BASE, 0xFF, GPIO_PIN_C_CORE_SELECT);
GPIOPinConfigureCoreSelect(GPIO_PORTC_BASE, 0xFF, GPIO_PIN_C_CORE_SELECT);
GPIOPinConfigureCoreSelect(GPIO_PORTD_BASE, 0xFF, GPIO_PIN_C_CORE_SELECT);
GPIOPinConfigureCoreSelect(GPIO_PORTE_BASE, 0xFF, GPIO_PIN_C_CORE_SELECT);
GPIOPinConfigureCoreSelect(GPIO_PORTF_BASE, 0xFF, GPIO_PIN_C_CORE_SELECT);
GPIOPinConfigureCoreSelect(GPIO_PORTG_BASE, 0xFF, GPIO_PIN_C_CORE_SELECT);
GPIOPinConfigureCoreSelect(GPIO_PORTH_BASE, 0xFF, GPIO_PIN_C_CORE_SELECT);
GPIOPinConfigureCoreSelect(GPIO_PORTJ_BASE, 0xFF, GPIO_PIN_C_CORE_SELECT);
// Delay
for (i=0;i<20;i++){};
// Disable clock supply for the watchdog modules
SysCtlPeripheralDisable(SYSCTL_PERIPH_WDOG1);
SysCtlPeripheralDisable(SYSCTL_PERIPH_WDOG0);
// Enable processor interrupts
IntMasterEnable();
#ifdef _STANDALONE
#ifdef _FLASH
// Send boot command to allow the C28 application to begin execution
IPCMtoCBootControlSystem(CBROM_MTOC_BOOTMODE_BOOT_FROM_FLASH);
#else
// Send boot command to allow the C28 application to begin execution
IPCMtoCBootControlSystem(CBROM_MTOC_BOOTMODE_BOOT_FROM_RAM);
#endif
#endif
// Main Code
while(1);
}
So my question is, is this a problem of my controlCARD that may be damaged or is it a general problem? Or there is something that I am doing wrong?
Thank you in advance for your help.
Pablo Armero
