From a498a1f984b1bc8701e0f403e0e349f59dfc2d6e Mon Sep 17 00:00:00 2001
From: Unknown <pfguenette@gmail.com>
Date: Mon, 9 Mar 2020 21:08:49 -0400
Subject: [PATCH] Convert endstop debounce_ms to a uint32 to avoid potential
 overflow bug

---
 Firmware/MotorControl/endstop.cpp | 4 ++--
 Firmware/MotorControl/endstop.hpp | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/Firmware/MotorControl/endstop.cpp b/Firmware/MotorControl/endstop.cpp
index f8fc4480..d4be0f41 100644
--- a/Firmware/MotorControl/endstop.cpp
+++ b/Firmware/MotorControl/endstop.cpp
@@ -10,14 +10,14 @@ void Endstop::update() {
     GPIO_TypeDef* gpio_port = get_gpio_port_by_pin(config_.gpio_num);
     bool last_pin_state = pin_state_;
     pin_state_ = HAL_GPIO_ReadPin(gpio_port, gpio_pin);
-    float now = axis_->loop_counter_ * current_meas_period;
+    uint32_t now = static_cast<uint32_t>(axis_->loop_counter_ * current_meas_period);
     if (pin_state_ != last_pin_state) {
         debounce_timer_ = now;
     }
     if (config_.enabled) {
         if ((now - debounce_timer_) >= (config_.debounce_ms * 0.001f)) {         // Debounce timer expired, take the new pin state
             endstop_state_ = config_.is_active_high ? pin_state_ : !pin_state_;  // endstop_state is the logical state
-            debounce_timer_ = now - (config_.debounce_ms * 0.001f);              // Ensure timer doesn't have overflow issues
+            debounce_timer_ = config_.debounce_ms;              // Ensure timer doesn't have overflow issues
         } else {
             endstop_state_ = endstop_state_;  // Do nothing
         }
diff --git a/Firmware/MotorControl/endstop.hpp b/Firmware/MotorControl/endstop.hpp
index eb1e3c8e..b5c6e6d8 100644
--- a/Firmware/MotorControl/endstop.hpp
+++ b/Firmware/MotorControl/endstop.hpp
@@ -5,7 +5,7 @@ class Endstop {
    public:
     struct Config_t {
         float offset = 0;
-        float debounce_ms = 50.0f;
+        uint32_t debounce_ms = 50;
         uint16_t gpio_num = 0;
         bool enabled = false;
         bool is_active_high = false;
@@ -42,6 +42,6 @@ class Endstop {
    private:
     bool pin_state_                = false;
     float pos_when_pressed_        = 0.0f;
-    volatile float debounce_timer_ = 0;
+    uint32_t debounce_timer_ = 0;
 };
 #endif
\ No newline at end of file