I am using a CC2530 and I want to use timer 3 to PWM two LEDs that are on my board. I have the LEDs connected to the correct Pins (Port 1, bits 3 and 4) and I have made sure no other functions on the chip are using timer 3. Since I want to use both ports for seperate PWMs I chose free running mode (0x00 to 0xFF) and compare mode 5 (set on compare, clear on 0xFF. However this does not seem to be working, when I turn either of the P1SEL bits high (whichever LED I want to be on) that port just goes high, no PWM. I have verified through debug that the timer is running and the correct P1SEL bits are getting set. Here is a code snippet:
#define GRN_LED_PWM (0x4F)#define RED_LED_PWM (0x07)#define GRN_LED_ON {P1SEL |= BIT4;}#define GRN_LED_OFF {P1SEL &= ~BIT4; P1 &= ~BIT4;}#define RED_LED_ON {P1SEL |= BIT3;}#define RED_LED_OFF {P1SEL &= ~BIT3; P1 &= ~BIT3;}
//Initialize Timer3 for LED PWM and I/O P1DIR |= BIT4 + BIT3; T3CTL |= BIT7 + BIT6 + BIT5 + BIT2; T3CCTL0 |= BIT5 + BIT3 + BIT2; T3CC0 = RED_LED_PWM; T3CCTL1 = T3CCTL0; T3CC1 = GRN_LED_PWM; T3CTL |= BIT4; //Start Timer 3
If anyone has any advice I would greatly appreciate it.
Hi Stephen,
Even if no other peripherals that use P1 are switched on, they are still taken into account in the priority for use of the P1 pins. You will probably need to set some priority bits to make sure Timer 3 has control of the P1 pins. Section 7.6.2 in the user guide may help:
"P2SEL.PRI2P1 and P2SEL.PRI3P1 select the order of precedence when assigning several peripherals to Port 1. The Timer 3 channels have precedence when both bits are set high."
I hope that helps.
Peder
have you solve this problem，i recently encountered the problem as similar as you，i want the timer3 of CC2530 to generate PWMs on P1.3 ,but no thing was get,if you solved the problem,can you share how you resolvethe process of the problem,thank you.