From 8ce66c6ec79e24fd69b9530213025831d0309646 Mon Sep 17 00:00:00 2001
From: Samuel Sadok <samuel.sadok@bluewin.ch>
Date: Fri, 27 Sep 2019 17:57:42 +0200
Subject: [PATCH] change power supply limit from watts to amps

---
 CHANGELOG.md                             | 2 +-
 Firmware/MotorControl/axis.cpp           | 9 +++++----
 Firmware/MotorControl/axis.hpp           | 3 ++-
 Firmware/MotorControl/odrive_main.h      | 3 ++-
 Firmware/communication/communication.cpp | 3 ++-
 5 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 685845fc..eb0d96f6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -16,7 +16,7 @@ Please add a note of your changes below this heading if you make a Pull Request.
 * Gain scheduling for anti-hunt when close to 0 position error
 * Velocity Limiting in Current Control mode according to `vel_limit` and `vel_gain`
 * Regen current limiting according to `max_regen_limit`, in Amps
-* DC Bus Power limiting according to `power_supply_wattage`
+* DC Bus hard current limiting according to `power_supply_min_current` and `power_supply_max_current`
 * Unit Testing with Doctest has been started for select algorithms, see [Firmware/Tests/test_runner.cpp](Firmware/Tests/test_runner.cpp)
 * Added support for Flylint VSCode Extension for static code analysis
 * Using an STM32F405 .svd file allows CortexDebug to view registers during debugging
diff --git a/Firmware/MotorControl/axis.cpp b/Firmware/MotorControl/axis.cpp
index 4319bb3c..21dd73ea 100644
--- a/Firmware/MotorControl/axis.cpp
+++ b/Firmware/MotorControl/axis.cpp
@@ -174,10 +174,11 @@ bool Axis::do_checks() {
         }
     }
 
-    if(board_config.power_supply_wattage > 0.0f && 
-            (Ibus_sum * vbus_voltage) > board_config.power_supply_wattage) 
-    {
-        error_ |= ERROR_DC_BUS_OVER_POWER;
+    if (Ibus_sum > board_config.power_supply_max_current) {
+        error_ |= ERROR_DC_BUS_OVER_CURRENT;
+    }
+    if (Ibus_sum < board_config.power_supply_min_current) {
+        error_ |= ERROR_DC_BUS_UNDER_CURRENT;
     }
 
     // Sub-components should use set_error which will propegate to this error_
diff --git a/Firmware/MotorControl/axis.hpp b/Firmware/MotorControl/axis.hpp
index 858df43b..46e3b15b 100644
--- a/Firmware/MotorControl/axis.hpp
+++ b/Firmware/MotorControl/axis.hpp
@@ -24,7 +24,8 @@ public:
         ERROR_MIN_ENDSTOP_PRESSED = 0x1000,
         ERROR_MAX_ENDSTOP_PRESSED = 0x2000,
         ERROR_ESTOP_REQUESTED = 0x4000,
-        ERROR_DC_BUS_OVER_POWER = 0x8000,
+        ERROR_DC_BUS_UNDER_CURRENT = 0x8000, // too much current pushed into the power supply
+        ERROR_DC_BUS_OVER_CURRENT = 0x10000, // too much current pulled out of the power supply
     };
 
     enum State_t {
diff --git a/Firmware/MotorControl/odrive_main.h b/Firmware/MotorControl/odrive_main.h
index 88f4de0c..88d7b902 100644
--- a/Firmware/MotorControl/odrive_main.h
+++ b/Firmware/MotorControl/odrive_main.h
@@ -83,7 +83,8 @@ struct BoardConfig_t {
                                                                         //<! This protects against cases in which the power supply fails to dissipate
                                                                         //<! the brake power if the brake resistor is disabled.
                                                                         //<! The default is 26V for the 24V board version and 52V for the 48V board version.
-    float power_supply_wattage = 0.0f;
+    float power_supply_max_current = INFINITY; // Max current [A] the power supply can source
+    float power_supply_min_current = 0.0f; // Max current [A] the power supply can sink
     PWMMapping_t pwm_mappings[GPIO_COUNT];
     PWMMapping_t analog_mappings[GPIO_COUNT];
 };
diff --git a/Firmware/communication/communication.cpp b/Firmware/communication/communication.cpp
index d7281d02..153d3e87 100644
--- a/Firmware/communication/communication.cpp
+++ b/Firmware/communication/communication.cpp
@@ -156,7 +156,8 @@ static inline auto make_obj_tree() {
             make_protocol_property("enable_ascii_protocol_on_usb", &board_config.enable_ascii_protocol_on_usb),
             make_protocol_property("dc_bus_undervoltage_trip_level", &board_config.dc_bus_undervoltage_trip_level),
             make_protocol_property("dc_bus_overvoltage_trip_level", &board_config.dc_bus_overvoltage_trip_level),
-            make_protocol_property("power_supply_wattage", &board_config.power_supply_wattage),
+            make_protocol_property("power_supply_min_current", &board_config.power_supply_min_current),
+            make_protocol_property("power_supply_max_current", &board_config.power_supply_max_current),
 #if HW_VERSION_MAJOR == 3 && HW_VERSION_MINOR >= 3
             make_protocol_object("gpio1_pwm_mapping", make_protocol_definitions(board_config.pwm_mappings[0])),
             make_protocol_object("gpio2_pwm_mapping", make_protocol_definitions(board_config.pwm_mappings[1])),