Posted on August 28, 2015 at 17:05
Here is my initializaion code for the TSC. When the acquisition is done I just read the value from TSC->IOGXCR and restart it after a delay (to allow for the capacitor to discharge properly).-------------------------------------------------------------------------- tsc init code GPIO_InitTypeDef GPIO_InitStructure; // turn on touch clock RCC->AHBENR |= RCC_AHBENR_TSEN; // setup io as af 3 RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE); GPIO_PinAFConfig(GPIOA, GPIO_PinSource0, GPIO_AF_3); GPIO_PinAFConfig(GPIOA, GPIO_PinSource1, GPIO_AF_3); // channels and sheilds should be push pull GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF; GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ; GPIO_Init(GPIOA, &GPIO_InitStructure); // sample should be open drain GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF; GPIO_InitStructure.GPIO_OType = GPIO_OType_OD; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ; GPIO_Init(GPIOA, &GPIO_InitStructure); // interrupt enable TSC->IER = 0x01; // int flag clear TSC->ICR = 0x03; // sampling TSC->IOSCR = (1 << 1); // channel TSC->IOCCR = 1; // enable the group TSC->IOGCSR = 1; union { uint32_t TSC_CR; struct { uint8_t TSCE :1; uint8_t START :1; uint8_t AM :1; uint8_t SYNCPOL :1; uint8_t IODEF :1; uint8_t MCV :3; uint8_t unused :4; uint8_t PGPSC :3; uint8_t SSPSC :1; uint8_t SSE :1; uint8_t SSD :7; uint8_t CTPL :4; uint8_t CTPH :4; } bits; } CR; CR.bits.CTPH = 0xf; // 16 clk high CR.bits.CTPL = 0xf; // 16 clk low CR.bits.SSD = 127; // 127 spread CR.bits.SSE = 0; // spread off CR.bits.SSPSC = 1; // spread clk/2 CR.bits.PGPSC = 0; // pulse clk /0 CR.bits.MCV = 6; // max count 16383 CR.bits.IODEF = 0; // default low CR.bits.SYNCPOL = 0;// sync pol CR.bits.AM = 0; // no sync CR.bits.START = 0; // aquisition start CR.bits.TSCE = 1; // module enable TSC->CR = CR.TSC_CR; // start TSC->CR |= 2;-------------------------------------------------------------- end of codeDoes anyone know what the problem might be? #tsc-sawtooth
Hi, I have a problem with the Touch Sense (TSC) module. No matter how I configure it and measure I always get a sawtooth wave added to it with an amplitude of a few percent of the total count. It seems to remain fairly constant in time with a period of about 80 seconds (haven't measured it exactly). I can't find any external sources for it nor internal. Even with all peripherals off except for TSC it's still present. If you turn of the TSC periodically and then after a while start to measure again you can see that the rise has been ongoing while the TSC has been disabled.
Here is my initializaion code for the TSC. When the acquisition is done I just read the value from TSC->IOGXCR and restart it after a delay (to allow for the capacitor to discharge properly).-------------------------------------------------------------------------- tsc init code GPIO_InitTypeDef GPIO_InitStructure; // turn on touch clock RCC->AHBENR |= RCC_AHBENR_TSEN; // setup io as af 3 RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE); GPIO_PinAFConfig(GPIOA, GPIO_PinSource0, GPIO_AF_3); GPIO_PinAFConfig(GPIOA, GPIO_PinSource1, GPIO_AF_3); // channels and sheilds should be push pull GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF; GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ; GPIO_Init(GPIOA, &GPIO_InitStructure); // sample should be open drain GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF; GPIO_InitStructure.GPIO_OType = GPIO_OType_OD; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ; GPIO_Init(GPIOA, &GPIO_InitStructure); // interrupt enable TSC->IER = 0x01; // int flag clear TSC->ICR = 0x03; // sampling TSC->IOSCR = (1 << 1); // channel TSC->IOCCR = 1; // enable the group TSC->IOGCSR = 1; union { uint32_t TSC_CR; struct { uint8_t TSCE :1; uint8_t START :1; uint8_t AM :1; uint8_t SYNCPOL :1; uint8_t IODEF :1; uint8_t MCV :3; uint8_t unused :4; uint8_t PGPSC :3; uint8_t SSPSC :1; uint8_t SSE :1; uint8_t SSD :7; uint8_t CTPL :4; uint8_t CTPH :4; } bits; } CR; CR.bits.CTPH = 0xf; // 16 clk high CR.bits.CTPL = 0xf; // 16 clk low CR.bits.SSD = 127; // 127 spread CR.bits.SSE = 0; // spread off CR.bits.SSPSC = 1; // spread clk/2 CR.bits.PGPSC = 0; // pulse clk /0 CR.bits.MCV = 6; // max count 16383 CR.bits.IODEF = 0; // default low CR.bits.SYNCPOL = 0;// sync pol CR.bits.AM = 0; // no sync CR.bits.START = 0; // aquisition start CR.bits.TSCE = 1; // module enable TSC->CR = CR.TSC_CR; // start TSC->CR |= 2;-------------------------------------------------------------- end of codeDoes anyone know what the problem might be? #tsc-sawtooth
