MSP430 digital tube display problem

某蓝色外功心法

MSP430 digital tube display problem [Copy link]

When I was familiar with MSP430F149 recently, I used a learning board to program an eight-digit digital tube to display the numbers 0-7 in a cycle. I found that after downloading the program into 430 using the downloader, the segment code displayed normally, but the bit code was always abnormal, and each time the microcontroller was powered on, the result displayed by the digital tube was different, and the program running results were different each time. I would like to ask all the experts to help me figure out what is going on. Thank you very much! The program code and learning board circuit diagram are as follows: #include "msp430x14x.h" void delay( int i) { while(i>0) { i--; } } int cnt; int n; int duanma[16] = {0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71}; int weima[8] = {0xfe,0xfd,0xfb,0xf7,0xef,0xdf,0xbf,0x7f}; void main( void ) { // Stop watchdog timer to prevent time out reset WDTCTL = WDTPW + WDTHOLD; //Clock setting of time base module //When the microcontroller is powered on, the source of the MCLK main clock is selected by default as provided by DCO. The default setting of the F1 series DCO is 800KHZ. //The default setting of the ACLK auxiliary clock is XT1, and XT1 is generally connected to a 32768HZ crystal. //The default setting of the SMCLK sub-clock is DCO, which is also 800KHZ. //XT2 needs to be turned on manually, and it is necessary to detect whether it is turned on successfully. BCSCTL1 &= ~(XT2OFF + XTS); //Start the XT2 high-speed clock module// BCSCTL3 |= XT2S3; //XT2 was just turned on, and it takes a certain amount of time for XT2 to enter a stable state. So it is necessary to wait and detect the stable state. do { IFG1 &=~OFIFG; //Clear OSCFault flag for(n=0xff;n>0;n--); //Delay and wait for it to turn on and stabilize} while((IFG1 & OFIFG) !=0); //Check whether the OSCFault flag is 0. If it is 0, it means that XT2 is turned on and stabilized. //Otherwise keep waiting... BCSCTL2 |= SELM1; //MCLK master clock selects XT2 as the clock source. TX2 input is not divided. BCSCTL2 &= ~SELS; //SMCLK selects DCO as the clock source. //----------------------------------------------- //-----------------Initialize IO ports P1DIR = 0xff; P1OUT = 0xff; P2DIR = 0xff; P2OUT = 0xff; P3DIR = 0xff; P3OUT = 0xff; P4DIR = 0xff; P4OUT = 0xff; P5DIR = 0xff; P5OUT = 0x5f; P6DIR = 0xff; P6OUT = 0xbf; cnt = 0;//------------------ TACCTL0 = CCIE; CCR0 = 8000; TACTL = TASSEL_2 + MC_1; _EINT(); while(1); } #pragma vector=TIMER0_A0_VECTOR __interrupt void Timer_A (void) { _DINT(); while(cnt<8) { P4OUT = duanma[cnt]; P6OUT |= BIT6; delay(10); P6OUT = 0x00; P4OUT = weima[cnt]; P5OUT |= BIT5; delay(10); P5OUT = 0x00; delay(30000); delay(30000); delay(30000); delay(30000); delay(30000); delay(30000); delay(30000); delay(30000); delay(30000); delay(30000); delay(30000); delay(30000); delay(30000); cnt++; } cnt = 0; _EINT(); }

tuago尤

The segment select and bit select of the digital tube connected through 74HC573 should not be connected to the same group of IO ports (PD0~PD7) ---> P4

某蓝色外功心法

tuago尤 posted on 2018-11-15 11:09 The segment select and bit select of the digital tube connected through 74HC573 should not be connected to the same group of IO ports (PD0~PD7)--->P4

Thank you for your reply! However, this hardware connection diagram has been drawn on the learning board, so we have no way to modify it when we use it. If you draw the board yourself, you can consider trying this way. Based on this hardware, theoretically, the above functions can be achieved through the control of P55 and P66.

szjrft

Don't understand code

某蓝色外功心法

szjrft posted on 2018-11-15 15:21 I don’t understand code

某蓝色外功心法

Solved! The problem lies in the circuit design of the learning board itself! Because the learning board may not have taken into account the load capacity of the microcontroller pin when designing the circuit, the microcontroller pin P55 is directly connected to the above-mentioned 74HC573 shift register. At the same time, P55 is also connected to an 8-way bus transceiver and a 3.3V to 5V SN74LVC4245 chip as shown below, resulting in the high-level voltage output by the microcontroller P55 pin being only about 0.3V. The correct logical judgment cannot be achieved on the 74HC573, which leads to problems with the digital tube shift! Get it! Learned!

xiaowai90

I just came to take a look.

alan000345

I learned a lot from following this, it’s a good post

tiankai001

Therefore, microcontroller debugging is not just program debugging, but also hardware circuit debugging.