From c5f06845c2b5eb3242654451ca640d615ac8362e Mon Sep 17 00:00:00 2001
From: Paul Guenette <pfguenette@gmail.com>
Date: Mon, 25 Mar 2019 20:04:45 +0100
Subject: [PATCH 1/3] Allow for regen current before braking

---
 Firmware/MotorControl/low_level.cpp | 8 ++++----
 Firmware/MotorControl/odrive_main.h | 1 +
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/Firmware/MotorControl/low_level.cpp b/Firmware/MotorControl/low_level.cpp
index 82e54049..2b834e55 100644
--- a/Firmware/MotorControl/low_level.cpp
+++ b/Firmware/MotorControl/low_level.cpp
@@ -585,10 +585,10 @@ void update_brake_current() {
             Ibus_sum += axes[i]->motor_.current_control_.Ibus;
         }
     }
-    float brake_current = -Ibus_sum;
-    // Clip negative values to 0.0f
-    if (brake_current < 0.0f) brake_current = 0.0f;
-    float brake_duty = brake_current * board_config.brake_resistance / vbus_voltage;
+    
+    // Don't start braking until -Ibus > regen_current_allowed
+    float brake_current        = std::max(-Ibus_sum - board_config.max_regen_current, 0.0f);
+    float brake_duty           = std::max(brake_current * std::abs(board_config.brake_resistance) / vbus_voltage, 0.0f);
 
     // Duty limit at 90% to allow bootstrap caps to charge
     // If brake_duty is NaN, this expression will also evaluate to false
diff --git a/Firmware/MotorControl/odrive_main.h b/Firmware/MotorControl/odrive_main.h
index 8bff6d81..d8e569da 100644
--- a/Firmware/MotorControl/odrive_main.h
+++ b/Firmware/MotorControl/odrive_main.h
@@ -71,6 +71,7 @@ struct BoardConfig_t {
     bool enable_uart = true;
     bool enable_i2c_instead_of_can = false;
     bool enable_ascii_protocol_on_usb = true;
+    float max_regen_current = 0.0f;
 #if HW_VERSION_MAJOR == 3 && HW_VERSION_MINOR >= 5 && HW_VERSION_VOLTAGE >= 48
     float brake_resistance = 2.0f;     // [ohm]
 #else

From a7dfb6ca060b6d3a483426797d0cdee2bec9f4f9 Mon Sep 17 00:00:00 2001
From: Oskar Weigl <oskar.weigl@gmail.com>
Date: Thu, 30 Jan 2020 13:31:20 -0800
Subject: [PATCH 2/3] add max regen current to protocl

---
 Firmware/communication/communication.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Firmware/communication/communication.cpp b/Firmware/communication/communication.cpp
index 79982e64..fe426a9d 100644
--- a/Firmware/communication/communication.cpp
+++ b/Firmware/communication/communication.cpp
@@ -152,6 +152,7 @@ static inline auto make_obj_tree() {
         ),
         make_protocol_object("config",
             make_protocol_property("brake_resistance", &board_config.brake_resistance),
+            make_protocol_property("max_regen_current ", &board_config.max_regen_current ),
             // TODO: changing this currently requires a reboot - fix this
             make_protocol_property("enable_uart", &board_config.enable_uart),
             make_protocol_property("enable_i2c_instead_of_can" , &board_config.enable_i2c_instead_of_can), // requires a reboot

From 8cbc09e168186ccd1454daf5111727d027b6f11f Mon Sep 17 00:00:00 2001
From: Oskar Weigl <oskar.weigl@gmail.com>
Date: Thu, 30 Jan 2020 16:16:39 -0800
Subject: [PATCH 3/3] feed watchdog on enter closed loop

---
 Firmware/MotorControl/axis.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Firmware/MotorControl/axis.cpp b/Firmware/MotorControl/axis.cpp
index 8ed9a4a3..6a3d0444 100644
--- a/Firmware/MotorControl/axis.cpp
+++ b/Firmware/MotorControl/axis.cpp
@@ -419,6 +419,7 @@ void Axis::run_state_machine_loop() {
                     goto invalid_state_label;
                 if (!encoder_.is_ready_)
                     goto invalid_state_label;
+                watchdog_feed();
                 status = run_closed_loop_control_loop();
             } break;