LUA : restructure to manage prearm-checks

To manage pre-arm checks from multiple modules, this is subdivided into
 - cx_build_in_test.lua : main module for built in tests
 - cx_modules : directory containing all sub modules
 - cx_utils : libraries support other modules

libraries/AP_HAL_ChibiOS/hwdef/CarbonixCommon/scripts/bit_subsystems/esc.lua

@@ -0,0 +1,168 @@
+local cx_msg = require("scripts.utils.msg")
+local aircraft_type = require("scripts.utils.aircraft")
+
+local ESC = {
+    name = "ESC",
+
+    number_of_esc = 5,
+
+    -- CONSTANTS
+    ESC_WARMUP_TIME = 3000,
+    ESC_RPM_THRESHOLD = 10,
+    SERVO_OUT_THRESHOLD = 1010,
+
+    -- Add a new table to store the warm-up end times for each ESC
+    esc_warmup_end_time = {},
+
+    srv_prv_telem_ms = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
+    srv_telem_in_err_status  = {false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false},
+    srv_rpm_in_err_status  = {false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false},
+
+
+    -- Counters to debounce nil checks on esc rpm and servo output, this is a
+    -- workaround to avoid giving the pilot a critical warning for an unexplained
+    -- one-loop dropout we saw recently
+    NIL_WARN_THRESHOLD = 3,
+    esc_rpm_nil_counter = {0, 0, 0, 0, 0},
+    servo_out_nil_counter = {0, 0, 0, 0, 0},
+
+    srv_number = {
+        [1] = {"Motor1", 33},
+        [2] = {"Motor2", 34},
+        [3] = {"Motor3", 35},
+        [4] = {"Motor4", 36},
+        [5] = {"Motor5", 70},
+        [6] = {"Motor6", 38},
+        [7] = {"Elevator", 19},
+        [8] = {"Rudder", 21},
+        [9] = {"GPIO", -1},
+        [10] = {"Script1", 94},
+        [11] = {"Aileron", 4}
+    },
+}
+
+-- Get the number of ESCs based on the aircraft type
+function ESC:get_num_esc()
+    if aircraft_type == "Volanti" then
+        self.number_of_esc = 5
+    elseif aircraft_type == "Ottano" then
+        self.number_of_esc = 4
+    else
+        assert(false, "ESC init failed: Aircraft type not set")
+    end
+end
+
+-- Initialize the ESC module
+function ESC:init()
+    self:get_num_esc()
+    if self.number_of_esc == 0 then
+        cx_msg:send(cx_msg.MAV_SEVERITY.CRITICAL, "ESC init failed: Aircraft type not set")
+        return
+    end
+    for i = 1, self.number_of_esc do
+        self.esc_warmup_end_time[i] = nil
+        self.srv_prv_telem_ms[i] = 0
+    end
+    cx_msg:send(cx_msg.MAV_SEVERITY.INFO, "ESC init (" .. aircraft_type .. ": " .. self.number_of_esc .. " ESCs)")   
+end
+
+
+-- Call this function whenever a motor starts running
+function ESC:esc_is_started(i)
+    -- Set the warm-up end time for this ESC to 3 seconds from now
+    self.esc_warmup_end_time[i] = millis() + self.ESC_WARMUP_TIME
+end
+
+-- Call this function whenever a motor stops running
+function ESC:esc_is_stopped(i)
+    -- Clear the warm-up end time for this ESC
+    self.esc_warmup_end_time[i] = nil
+end
+
+function ESC:update()
+    for i = 1, self.number_of_esc  do
+        local esc_last_telem_data_ms = esc_telem:get_last_telem_data_ms(i-1):toint()
+        local esc_rpm = esc_telem:get_rpm(i-1)
+        local servo_out = SRV_Channels:get_output_pwm(self.srv_number[i][2])
+        -- Telem data timestamp check
+        if not esc_last_telem_data_ms or esc_last_telem_data_ms == 0 or esc_last_telem_data_ms == self.srv_prv_telem_ms[i] then
+            if self.srv_telem_in_err_status[i] == false then
+                cx_msg:send(cx_msg.MAV_SEVERITY.CRITICAL, "ESC " .. i .. " Telemetry Lost")
+                self.srv_telem_in_err_status[i] = true
+            end
+        -- Nil check for RPM reading
+        elseif not esc_rpm then
+            self.esc_rpm_nil_counter[i] = self.esc_rpm_nil_counter[i] + 1
+            if self.esc_rpm_nil_counter[i] < self.NIL_WARN_THRESHOLD then
+                cx_msg:send(cx_msg.MAV_SEVERITY.INFO, "ESC " .. i .. " RPM nil")
+            elseif self.srv_rpm_in_err_status[i] == false then
+                cx_msg:send(cx_msg.MAV_SEVERITY.CRITICAL, "ESC " .. i .. " RPM nil")
+                self.srv_telem_in_err_status[i] = true
+            end
+        -- Nil check for servo output
+        elseif not servo_out then
+            self.servo_out_nil_counter[i] = self.servo_out_nil_counter[i] + 1
+            if self.servo_out_nil_counter[i] < self.NIL_WARN_THRESHOLD then
+                cx_msg:send(cx_msg.MAV_SEVERITY.INFO, "ESC " .. i .. " Servo Out nil")
+            elseif self.srv_rpm_in_err_status[i] == false then
+                cx_msg:send(cx_msg.MAV_SEVERITY.CRITICAL, "ESC " .. i .. " Servo Out nil")
+                self.srv_telem_in_err_status[i] = true
+            end
+        -- Telemetry data is fresh and valid
+        else
+            if self.srv_telem_in_err_status[i] == true then
+                cx_msg:send(cx_msg.MAV_SEVERITY.INFO, "ESC " .. i .. " Telemetry Recovered")
+                self.srv_telem_in_err_status[i] = false
+                self.servo_out_nil_counter[i] = 0
+                self.esc_rpm_nil_counter[i] = 0
+            end
+            -- If armed, check that the motor is actually turning when it is commanded to
+            if arming:is_armed() then
+                -- If the PWM is below the threshold, it is okay for the motor to be stopped
+                if servo_out < self.SERVO_OUT_THRESHOLD then
+                    self:esc_is_stopped(i)
+                -- If the PWM has just gone above the threshold, start the warm-up timer
+                elseif servo_out > self.SERVO_OUT_THRESHOLD and not self.esc_warmup_end_time[i]  then
+                    self:esc_is_started(i)
+                -- If the motor is running, and the warmup timer has expired, check that the motor is spinning
+                elseif self.esc_warmup_end_time[i] and millis() > self.esc_warmup_end_time[i] then
+                    if servo_out > self.SERVO_OUT_THRESHOLD and esc_rpm < self.ESC_RPM_THRESHOLD then
+                        if self.srv_rpm_in_err_status[i] == false then
+                            cx_msg:send(cx_msg.MAV_SEVERITY.CRITICAL, "ESC " .. i .. " RPM Drop")
+                            self.srv_rpm_in_err_status[i] = true
+                        end
+                    else
+                        if self.srv_rpm_in_err_status[i] == true then
+                            cx_msg:send(cx_msg.MAV_SEVERITY.INFO, "ESC " .. i .. " RPM Recovered")
+                            self.srv_rpm_in_err_status[i] = false
+                        end
+                    end
+                end
+            end
+        end
+        -- Update srv_prv_telem_ms[i] if it had valid data this loop
+        if esc_last_telem_data_ms and esc_last_telem_data_ms ~= 0 then
+            self.srv_prv_telem_ms[i] = esc_last_telem_data_ms
+        end
+    end
+end
+
+-- Return error code
+function ESC:check_for_errors()
+    local error_count = 0
+    for _, status in ipairs(self.srv_telem_in_err_status) do
+        if status then
+            error_count = error_count + 1
+        end
+    end
+    for _, status in ipairs(self.srv_rpm_in_err_status) do
+        if status then
+            error_count = error_count + 1
+        end
+    end
+
+    -- No errors found
+    return error_count
+end
+
+return ESC