clean up SPI code

This commit is contained in:
King Kévin 2016-01-22 16:33:03 +01:00
parent ad7754d488
commit 21a2567d1d
3 changed files with 18 additions and 49 deletions

View File

@ -350,7 +350,6 @@ void vfd_matrix(uint8_t nb, char c)
/* shift out the VFD data */
void vfd_shift(void)
{
// prepare SPI data
for (uint8_t i=0; i<LENGTH(vfd_data) && (uint8_t)(i*2+1)<LENGTH(vfd_spi); i++) {
vfd_spi[i*2] = vfd_data[i];
@ -358,29 +357,8 @@ void vfd_shift(void)
}
vfd_spi_i = 0;
spi_enable(VFD_SPI); // enable SPI (the tx empty interrupt will trigger)
//while (true) {
//spi_send(VFD_SPI, vfd_spi[vfd_spi_i++]); // send first data (also enables latch)
//}
/*
gpio_clear(VFD_PORT, VFD_NLE); // do not latch data
gpio_set(VFD_PORT, VFD_CLK); // clock is idle high
for (uint8_t i=0; i<sizeof(vfd_data)/sizeof(vfd_data[0]); i++) {
for (uint8_t b=0; b<32; b++) {
gpio_clear(VFD_PORT, VFD_CLK); // change data on low
if (vfd_data[i]&(1<<b)) { // shift the value
gpio_set(VFD_PORT, VFD_DIN);
} else {
gpio_clear(VFD_PORT, VFD_DIN);
}
gpio_set(VFD_PORT, VFD_CLK); // signal need to be valid on high edge
}
}
gpio_set(VFD_PORT, VFD_NLE); // latch data
gpio_clear(VFD_PORT, VFD_NLE); // stop latching data
*/
// enable SPI (the tx empty interrupt will trigger)
spi_enable(VFD_SPI);
}
/* transmit every digit and matrix */
@ -456,15 +434,11 @@ void vfd_off(void)
void vfd_setup(void)
{
rcc_periph_clock_enable(VFD_PORT_RCC); // enable clock for VFD GPIO
gpio_set_mode(VFD_PORT, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, VFD_STR); // set VFD pin to 'output push-pull'
gpio_set_mode(VFD_PORT, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, VFD_NLE); // set VFD pin to alternative function push-pull
//gpio_set_mode(VFD_PORT, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, VFD_DIN);
//gpio_set_mode(VFD_PORT, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, VFD_CLK);
gpio_set_mode(VFD_PORT, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, VFD_STR); // set VFD pin to output push-pull
gpio_set_mode(VFD_PORT, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, VFD_NLE); // set VFD pin to output push-pull
gpio_set(VFD_PORT, VFD_STR); // disable HV output
gpio_clear(VFD_PORT, VFD_NLE); // do not output latched data
//gpio_set(VFD_PORT, VFD_CLK); // clock is idle high
rcc_periph_clock_enable(VFD_SPI_RCC); // enable SPI clock
gpio_set_mode(VFD_PORT, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, VFD_CLK); // set VFD pin to alternative function push-pull
@ -479,20 +453,21 @@ void vfd_setup(void)
* - send 16 bits at a time
* - send least significant bit first (that's how I coded the data)
*/
spi_init_master(VFD_SPI, SPI_CR1_BAUDRATE_FPCLK_DIV_64, SPI_CR1_CPOL_CLK_TO_1_WHEN_IDLE, SPI_CR1_CPHA_CLK_TRANSITION_2, SPI_CR1_DFF_16BIT, SPI_CR1_LSBFIRST);
spi_init_master(VFD_SPI, SPI_CR1_BAUDRATE_FPCLK_DIV_8, SPI_CR1_CPOL_CLK_TO_1_WHEN_IDLE, SPI_CR1_CPHA_CLK_TRANSITION_2, SPI_CR1_DFF_16BIT, SPI_CR1_LSBFIRST);
//spi_set_bidirectional_transmit_only_mode(VFD_SPI); // only use MOSI to transmit
//spi_set_unidirectional_mode(VFD_SPI); // MISO is unused
//spi_disable_software_slave_management(VFD_SPI); // use hardware NSS
spi_set_unidirectional_mode(VFD_SPI); // MISO is unused
/* set NSS high to enable transmission
* the NSS in STM32 can not be used as hardware slave select
* RM0008 reference manual 25.3.1 is misleading
* when hardware NSS is used and output is enabled NSS never goes up after transmission, even if SPI is disabled
* when software NSS is used, NSS can not be set high again, even when writing to the register
* the slave select must be done manually using GPIO */
spi_enable_software_slave_management(VFD_SPI);
//spi_enable_ss_output(VFD_SPI); // allow slave select
spi_set_nss_high(VFD_SPI); // set NSS high
spi_enable_tx_buffer_empty_interrupt(VFD_SPI); // enable TX empty interrupt
nvic_enable_irq(VFD_SPI_IRQ); // enable SPI interrupt
//spi_enable(VFD_SPI);
//SPI_CR1(VFD_SPI) &= ~SPI_CR1_SSM;
//SPI_CR2(VFD_SPI) |= SPI_CR2_SSOE;
vfd_clear(); // initialize values
}
@ -507,13 +482,7 @@ void spi2_isr(void)
gpio_clear(VFD_PORT, VFD_NLE); // slave select to latch data
spi_send(VFD_SPI, vfd_spi[vfd_spi_i++]); // send next data
} else { // all data transmitted
while (SPI_SR(VFD_SPI) & SPI_SR_BSY); // wait until transmission is complete (not sure it's a good idea in an isr)
gpio_set(VFD_PORT, VFD_NLE); // output latched data
//spi_set_nss_high(VFD_SPI); // set NSS high
spi_clean_disable(VFD_SPI); // disable latch to output data
//spi_set_nss_high(VFD_SPI); // set NSS high
gpio_set(GPIOA, GPIO1); // toggle LED
//gpio_set(VFD_PORT, VFD_NLE); // do not output latched data
spi_clean_disable(VFD_SPI); // wait for transmission to complete
}
}
}

View File

@ -37,8 +37,8 @@
/* latch enable pin
* store the shifted data on low
* output the parallel data on high
* use the SPI NSS (PA4) */
#define VFD_NLE GPIO_SPI1_NSS
* use GPIO (PA4) (NSS does not work as SS) */
#define VFD_NLE GPIO4
/* clock signal
* drive using SPI SCK (PA5) */
#define VFD_CLK GPIO_SPI1_SCK

2
main.c
View File

@ -108,7 +108,7 @@ int main(void)
vfd_flag = true;
}
while (vfd_flag) {
//vfd_flag = false;
vfd_flag = false;
gpio_toggle(LED_PORT, LED_PIN); // toggle LED
vfd_transmit();
}