DPM1000: add external discharge resistor control via GPIO

Signed-off-by: Cornelius Claussen <[email protected]>

modules/DPM1000/CMakeLists.txt

@@ -17,6 +17,7 @@ target_sources(${MODULE_NAME}
 target_link_libraries(${MODULE_NAME}
     PRIVATE
         can_protocols::dpm1000
+        everest::gpio
 )
 # ev@bcc62523-e22b-41d7-ba2f-825b493a3c97:v1
 

modules/DPM1000/DPM1000.hpp

@@ -26,6 +26,9 @@ struct Conf {
     double current_limit_A;
     double voltage_limit_V;
     std::string series_parallel_mode;
+    std::string discharge_gpio_chip;
+    int discharge_gpio_line;
+    bool discharge_gpio_polarity;
     bool debug_print_all_telemetry;
 };
 

modules/DPM1000/main/power_supply_DCImpl.cpp

@@ -103,6 +103,12 @@ void power_supply_DCImpl::init() {
     config_voltage_limit = mod->config.voltage_limit_V;
     config_power_limit = mod->config.power_limit_W;
 
+    if (!mod->config.discharge_gpio_chip.empty()) {
+        discharge_gpio.open(mod->config.discharge_gpio_chip, mod->config.discharge_gpio_line,
+                            !mod->config.discharge_gpio_polarity);
+        discharge_gpio.set_output(false);
+    }
+
     can_broker = std::make_unique<CanBroker>(mod->config.device, mod->config.device_address);
 
     // ensure the module is switched off
@@ -182,6 +188,14 @@ void power_supply_DCImpl::ready() {
             }
         }
 
+        // Discharge output if it is higher then setpoint voltage.
+        // Note that this has no timeout, so HW must be designed to sustain the worst case load (e.g. 1000V) continously
+        if (vc.voltage_V > (voltage + 10)) {
+            discharge_gpio.set(true);
+        } else {
+            discharge_gpio.set(false);
+        }
+
         if (mod->config.debug_print_all_telemetry) {
             // read additional meta data
             float current_real_part = 0, current_limit = 0, dcdc_temperature = 0, ac_voltage = 0, voltage_limit = 0,

modules/DPM1000/main/power_supply_DCImpl.hpp

@@ -14,6 +14,8 @@
 
 // ev@75ac1216-19eb-4182-a85c-820f1fc2c091:v1
 #include <atomic>
+
+#include <gpio.hpp>
 // ev@75ac1216-19eb-4182-a85c-820f1fc2c091:v1
 
 namespace module {
@@ -58,6 +60,8 @@ class power_supply_DCImpl : public power_supply_DCImplBase {
     float config_voltage_limit{0};
     float config_power_limit{0};
     float config_min_voltage_limit{50.};
+
+    Everest::Gpio discharge_gpio;
     // ev@3370e4dd-95f4-47a9-aaec-ea76f34a66c9:v1
 };
 

modules/DPM1000/manifest.yaml

@@ -37,6 +37,20 @@ config:
       - Parallel
       - Automatic
     default: Series
+  discharge_gpio_chip:
+    description: >-
+      GPIO chip to use to switch external discharge load on and off. An empty string disables discharging.
+      Note that the hardware load must be designed to allow permanent discharge from the highest voltage (e.g. 1000V)
+    type: string
+    default: ''
+  discharge_gpio_line:
+    description: GPIO line to use to switch discharge load
+    type: integer
+    default: 0
+  discharge_gpio_polarity:
+    description: GPIO polarity, false means active low, true means active high
+    type: boolean
+    default: true
   debug_print_all_telemetry:
     description: Read and print all telemetry from the power module. Helpful while debugging.
     type: boolean