From: Federica Di Lauro <federicadilauro1998@gmail.com>
Date: Tue, 8 Oct 2019 09:11:58 +0000 (+0200)
Subject: ticks to linear velocity
X-Git-Url: http://git.leonardobizzoni.com/?a=commitdiff_plain;h=8e2ed0f893114dc4e0263954d30b27e6d7497640;p=pioneer-stm32

ticks to linear velocity
---

diff --git a/otto_controller_source/Inc/encoder.h b/otto_controller_source/Inc/encoder.h
index 45e614f..f3cd05b 100644
--- a/otto_controller_source/Inc/encoder.h
+++ b/otto_controller_source/Inc/encoder.h
@@ -9,6 +9,7 @@ class Encoder {
   uint32_t elapsed_millis;
   uint32_t kTicksPerRevolution = 148000;
   float kPi = 3.14159;
+  float kWheelCircumference = 0.7539; //in meters
 
   Encoder(TIM_HandleTypeDef* timer);
 
diff --git a/otto_controller_source/Src/encoder.cpp b/otto_controller_source/Src/encoder.cpp
index b658a14..47b8a84 100644
--- a/otto_controller_source/Src/encoder.cpp
+++ b/otto_controller_source/Src/encoder.cpp
@@ -6,13 +6,13 @@ Encoder::Encoder(TIM_HandleTypeDef* timer) {
   elapsed_millis = HAL_GetTick();
 }
 
-float Encoder::GetAngularVelocity(){
+float Encoder::GetLinearVelocity(){
   uint32_t ticks = this->GetCount();
   uint32_t previous_millis = this->elapsed_millis;
   this->elapsed_millis = HAL_GetTick();
-  float radiants = (ticks * 2 * kPi) / kTicksPerRevolution;
-  float angular_velocity = radiants /
+  float meters =  (ticks * kWheelCircumference) / kTicksPerRevolution;
+  float linear_velocity = meters /
       ((this->elapsed_millis - previous_millis) / 1000);
-  return angular_velocity;
+  return linear_velocity;
 }