From 9d87c925a9eaa4fc256be3173c14a20d1469472d Mon Sep 17 00:00:00 2001
From: fishsoupisgood <github@madingley.org>
Date: Wed, 9 Sep 2020 11:53:37 +0100
Subject: everything, mostly, working

---
 boiler-monster/stm32/app/ticker.c | 105 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 105 insertions(+)
 create mode 100644 boiler-monster/stm32/app/ticker.c

(limited to 'boiler-monster/stm32/app/ticker.c')

diff --git a/boiler-monster/stm32/app/ticker.c b/boiler-monster/stm32/app/ticker.c
new file mode 100644
index 0000000..9e268ca
--- /dev/null
+++ b/boiler-monster/stm32/app/ticker.c
@@ -0,0 +1,105 @@
+#include "project.h"
+
+
+static volatile uint32_t delay_hms_count;
+static volatile uint32_t ticks;
+static uint32_t scale = 7;
+
+void
+delay_us (uint32_t d)
+{
+  d *= scale;
+
+  while (d--)
+    __asm__ ("nop");
+}
+
+
+void
+sys_tick_handler (void)
+{
+  if (delay_hms_count)
+    delay_hms_count--;
+
+
+  led_tick();
+  ot_phy_tx_tick();
+  ot_tick();
+  onewire_tick();
+  temp_tick();
+  adc_tick();
+  pressure_tick();
+
+
+  ticks++;
+}
+
+
+
+void
+delay_ms (uint32_t d)
+{
+  delay_hms_count = d << 1;
+
+  while (delay_hms_count);
+}
+
+#if 0
+int
+timed_out (uint32_t then, unsigned int ms)
+{
+  then = ticks - then;
+
+  if (then > ms)
+    return 1;
+
+  return 0;
+}
+
+int
+timed_out_cycles (uint32_t then, unsigned int cycles)
+{
+  then = dwt_read_cycle_counter() - then;
+
+  if (then > cycles)
+    return 1;
+
+  return 0;
+}
+#endif
+
+
+
+void
+ticker_init (void)
+{
+  uint32_t v, w;
+
+  /*Start periodic timer */
+
+  systick_set_clocksource (STK_CSR_CLKSOURCE_AHB_DIV8);
+  /* 72MHz / 8 = > 9Mhz */
+  systick_set_reload (4500);
+  /* 9MHz / 4500 => 2kHz */
+  systick_interrupt_enable();
+  systick_counter_enable();
+
+  /*Calibrate the delay loop */
+
+
+
+  do {
+    scale--;
+    v = ticks;
+
+    while (v == ticks);
+
+    delay_us (500);
+    w = ticks;
+    v++;
+    w -= v;
+  } while (w);
+
+
+
+}
-- 
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