A simple IR RC probe

diff --git a/ir-probe/Makefile b/ir-probe/Makefile
new file mode 100644 (file)
index 0000000..81ed48b
--- /dev/null
+++ b/ir-probe/Makefile
@@ -0,0 +1,9 @@
+ROOT=..
+BINARY=test
+OBJS=test.o
+LIB_OBJS=util-debug.o
+
+WITH_BOOT_LOADER=1
+WITH_DFU_FLASH=1
+
+include $(ROOT)/mk/bluepill.mk

diff --git a/ir-probe/config.h b/ir-probe/config.h
new file mode 100644 (file)
index 0000000..2806e8c
--- /dev/null
+++ b/ir-probe/config.h
@@ -0,0 +1,7 @@
+// Processor clock
+
+#define CPU_CLOCK_MHZ 72
+
+// Debug port
+
+#define DEBUG_USART USART1

diff --git a/ir-probe/kerm b/ir-probe/kerm
new file mode 100644 (file)
index 0000000..988f567
--- /dev/null
+++ b/ir-probe/kerm
@@ -0,0 +1,5 @@
+set port /dev/ttyUSB0
+set speed 115200
+set flow-control none
+set carrier-watch off
+connect

diff --git a/ir-probe/test.c b/ir-probe/test.c
new file mode 100644 (file)
index 0000000..9a2520a
--- /dev/null
+++ b/ir-probe/test.c
@@ -0,0 +1,122 @@
+#include "util.h"
+
+#include <libopencm3/cm3/cortex.h>
+#include <libopencm3/cm3/nvic.h>
+#include <libopencm3/cm3/systick.h>
+#include <libopencm3/stm32/rcc.h>
+#include <libopencm3/stm32/gpio.h>
+#include <libopencm3/stm32/usart.h>
+
+static void clock_setup(void)
+{
+       rcc_clock_setup_in_hse_8mhz_out_72mhz();
+
+       rcc_periph_clock_enable(RCC_GPIOB);
+       rcc_periph_clock_enable(RCC_GPIOC);
+       rcc_periph_clock_enable(RCC_USART1);
+
+       rcc_periph_reset_pulse(RST_GPIOB);
+       rcc_periph_reset_pulse(RST_GPIOC);
+       rcc_periph_reset_pulse(RST_USART1);
+}
+
+static void gpio_setup(void)
+{
+       // PC13 = BluePill LED
+       gpio_set_mode(GPIOC, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO13);
+       gpio_clear(GPIOC, GPIO13);
+
+       // PB9 = SFH5110 output (5V tolerant)
+       gpio_set_mode(GPIOC, GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO9);
+}
+
+static void usart_setup(void)
+{
+       gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO_USART1_TX);
+
+       usart_set_baudrate(USART1, 115200);
+       usart_set_databits(USART1, 8);
+       usart_set_stopbits(USART1, USART_STOPBITS_1);
+       usart_set_mode(USART1, USART_MODE_TX_RX);
+       usart_set_parity(USART1, USART_PARITY_NONE);
+       usart_set_flow_control(USART1, USART_FLOWCONTROL_NONE);
+
+       usart_enable(USART1);
+}
+
+static void tick_setup(void)
+{
+       systick_set_reload(0xffffff);
+       systick_counter_enable();
+       systick_interrupt_disable();
+       systick_clear();
+}
+
+static u16 get_bit(void)
+{
+       return !gpio_get(GPIOB, GPIO9);
+}
+
+#define MAX_SAMPLES 1024
+u32 samples[MAX_SAMPLES];
+
+int main(void)
+{
+       clock_setup();
+       gpio_setup();
+       usart_setup();
+       tick_setup();
+
+       debug_puts("\n\n### Infrared Remote Control receiver ###\n\n");
+
+       for (;;) {
+               gpio_set(GPIOC, GPIO13);
+
+               if (get_bit()) {
+                       debug_puts("Waiting for silence\n");
+                       while (get_bit())
+                               ;
+               }
+               debug_puts("Ready...");
+
+               u16 last = 0;
+               uint nsamp = 0;
+               u32 start;
+
+               do {
+                       start = systick_get_value();
+                       last = get_bit();
+               } while (!last);
+
+               gpio_clear(GPIOC, GPIO13);
+
+               for (;;) {
+                       u32 now;
+                       u16 curr;
+                       uint len;
+                       do {
+                               now = systick_get_value();
+                               len = (start - now) & 0xffffff;
+                               if (len > 5000000) {
+                                       samples[nsamp++] = len;
+                                       goto timeout;
+                               }
+                               curr = get_bit();
+                       } while (curr == last);
+                       samples[nsamp++] = len;
+                       if (nsamp >= MAX_SAMPLES)
+                               break;
+                       start = now;
+                       last = curr;
+               }
+
+       timeout:
+               for (uint i=0; i<nsamp; i++) {
+                       debug_putc(i ? ' ' : '\n');
+                       debug_printf("%u", (samples[i] + CPU_CLOCK_MHZ - 1) / CPU_CLOCK_MHZ);   // in μs
+               }
+               debug_putc('\n');
+       }
+
+       return 0;
+}