"MSP430" key program (including circuit diagram and source code)
＃i nclude
void Init_ Port(void){ // Set all pins of P1 port as input mode during initialization P1DIR = 0; // Set all pins of port P1 as general I / O ports P1SEL = 0; // Set P1.4 P1.5 P1.6 P1.7 to the output direction P1DIR |= BIT4; P1DIR |= BIT5; P1DIR |= BIT6; P1DIR |= BIT7;
// Output low level first P1OUT = 0x00;
// Reset interrupt register P1IE = 0; P1IES = 0; P1IFG = 0; // Turn on the interrupt function of the pin // The corresponding pin jumps from high to low level to set the corresponding flag P1IE |= BIT0; P1IES |= BIT0; P1IE |= BIT1; P1IES |= BIT1; P1IE |= BIT2; P1IES |= BIT2; P1IE |= BIT3; P1IES |= BIT3; _ EINT();// Open interrupt return;} void Delay(void){ int i; for(i = 100; i--; i > 0) ;// Delay a little time}int keyprocess (void){ int nP10,nP11,nP12,nP13; int nRes = 0; // P1.4 output low level P1OUT &= ~(BIT4); nP10 = P1IN & BIT0; if (nP10 == 0) nRes = 13; nP11 = P1IN & BIT1; if (nP11 == 0) nRes = 14; nP12 = P1IN & BIT2; if (nP12 == 0) nRes = 15; nP13 = P1IN & BIT3; if (nP13 == 0) nRes = 16; // P1.5 output low level P1OUT &= ~(BIT4); nP10 = P1IN & BIT0; if (nP10 == 0) nRes = 9; nP11 = P1IN & BIT1; if (nP11 == 0) nRes = 10; nP12 = P1IN & BIT2; if (nP12 == 0) nRes = 11; nP13 = P1IN & BIT3; if (nP13 == 0) nRes = 12; // P1.6 output low level P1OUT &= ~(BIT4); nP10 = P1IN & BIT0; if (nP10 == 0) nRes = 5; nP11 = P1IN & BIT1; if (nP11 == 0) nRes = 6; nP12 = P1IN & BIT2; if (nP12 == 0) nRes = 7; nP13 = P1IN & BIT3; if (nP13 == 0) nRes = 8; // P1.7 output low level P1OUT &= ~(BIT4); nP10 = P1IN & BIT0; if (nP10 == 0) nRes = 1; nP11 = P1IN & BIT1; if (nP11 == 0) nRes = 2; nP12 = P1IN & BIT2; if (nP12 == 0) nRes = 3; nP13 = P1IN & BIT3; if (nP13 == 0) nRes = 4;
P1OUT = 0x00;// Restore previous values.
// Read the status of each pin nP10 = P1IN & BIT0; nP11 = P1IN & BIT1; nP12 = P1IN & BIT2; nP13 = P1IN & BIT3; for(;;) { if(nP10 == 1 && nP11 == 1 && nP12 == 1 && nP13 == 1) { // Wait for the key to be released break; } } return nRes;}// Process interrupt from port 1 [port1]_ VECTOR] void PORT_ ISR(void){ Delay(); KeyProcess(); if(P1IFG & BIT0) { P1IFG &= ~(BIT0);// Clear interrupt flag bit } if(P1IFG & BIT1) { P1IFG &= ~(BIT1);// Clear interrupt flag bit } if(P1IFG & BIT2) { P1IFG &= ~(BIT2);// Clear interrupt flag bit } if(P1IFG & BIT3) { P1IFG &= ~(BIT3);// Clear interrupt flag bit }} void Init_ CLK(void){ unsigned int i; BCSCTL1 = 0X00; // Clear the contents of the register // XT2 oscillator on // Lftx1 operates in low frequency mode // The frequency division factor of aclk is 1 do { IFG1 &= ~OFIFG; // Clear oscfault flag for (i = 0x20; i > 0; i--); } while ((IFG1 & OFIFG) == OFIFG); // If oscfault = 1 BCSCTL2 = 0X00; // Clear the contents of the register BCSCTL2 += SELM1; // The clock source of MCLK is tx2clk, and the frequency division factor is 1 BCSCTL2 += SELS; // The clock source of smclk is tx2clk, and the frequency division factor is 1}
MSP430 key interface circuit diagram, technical zone
How do bare metal programs drive hardware? Look what the elder said
Introduction and configuration of arm tightly coupled memory
Armv8 simplifies software migration through design
The higher priority of STM32 interrupt is mainly determined according to two aspects
Design scheme of master-slave Dual CPU embedded four-axis motion controller based on arm and DSP“
Our other product:
