lua: cruise control example

By Dmitriy Zav

only:uaefi

Author: dron0gus

firmware/controllers/lua/examples/CruiseCheck.lua

@@ -0,0 +1,162 @@
+-- Cruise Control + Check Engine LED
+--
+-- Hardware:
+--   LED          : PWM output 0, 50 Hz
+--   Buttons      : AuxAnalog 0, resistor-ladder
+--     Set        : 0.75-1.40 V   -- engage / disengage cruise 4x4.7k in parallel
+--     Decrease   : 1.80-2.70 V   -- target RPM - RPM_STEP 2x4.7k in parallel
+--     Increase   : 2.90-3.55 V   -- target RPM + RPM_STEP 1x4.7k 
+--     No button  : all other voltages
+--   Brake pedal  : getOutput("brakePedalState")
+--
+-- LED priority (highest first):
+--   1. Fault (CLT > 100)        -- blink 1 s period, 100 %
+--   2. Engine stopped (RPM = 0) -- 100 % steady
+--   3. Cruise active            -- 50 % steady
+--   4. Normal run               -- off
+
+-- ========= tuneable constants =========
+local CRUISE_MIN_RPM   = 1200  -- minimum RPM to allow engagement
+local CRUISE_MAX_RPM   = 4000  -- RPM above this forces disengagement
+local RPM_STEP         = 100   -- RPM per increase / decrease press
+local CLT_FAULT_TEMP   = 100   -- degrees C for fault LED blink
+local PID_KP           = 0.02  -- %ETB per RPM of error
+local PID_KI           = 0.003 -- integrator gain
+local PID_MIN          = 0.0   -- don't wont to decrease ETB below baseline
+local PID_MAX          = 50.0  -- limit max ETB increase to avoid big throttle jumps
+local BLINK_HALF       = 0.5   -- fault blink half-period [s]
+local DEBOUNCE         = 20    -- ticks of stable reading (~100 ms at 200 Hz)
+-- ======================================
+
+-- button state constants
+local BTN_NONE     = 0
+local BTN_SET      = 1
+local BTN_DECREASE = 2
+local BTN_INCREASE = 3
+
+startPwm(0, 50, 0)  -- LED: PWM output 0, 50 Hz, off
+
+local pid = Pid.new(PID_KP, PID_KI, 0, PID_MIN, PID_MAX)
+
+local cruiseActive = false
+local targetRpm    = 0
+
+-- debounce state
+local btnCandidate = BTN_NONE
+local btnCount     = 0
+local btnStable    = BTN_NONE
+local btnPrev      = BTN_NONE
+
+-- LED blink state
+local blinkTimer = Timer.new()
+local blinkOn    = false
+
+-- ---- helpers ----
+
+local function readBtn()
+    local v = getAuxAnalog(0)
+    if v == nil                then return BTN_NONE     end
+    if v >= 0.75 and v <= 1.40 then return BTN_SET      end
+    if v >= 1.80 and v <= 2.70 then return BTN_DECREASE end
+    if v >= 2.90 and v <= 3.55 then return BTN_INCREASE end
+    return BTN_NONE
+end
+
+local function disengageCruise()
+    cruiseActive = false
+    pid:reset()
+    setEtbAdd(0)
+    setLuaGauge(1, 0)
+    setLuaGauge(2, 0)
+    print("Cruise OFF")
+end
+
+-- ---- main loop ----
+
+function onTick()
+    local rpm = getSensor("RPM") or 0
+
+    -- ---- button debounce ----
+    local raw = readBtn()
+    if raw == btnCandidate then
+        btnCount = btnCount + 1
+        if btnCount >= DEBOUNCE then btnStable = btnCandidate end
+    else
+        btnCandidate = raw
+        btnCount     = 1
+    end
+
+    -- ---- single-fire edge detection (none -> button) ----
+    if btnStable ~= BTN_NONE and btnPrev == BTN_NONE then
+        if btnStable == BTN_SET then
+            if not cruiseActive then
+                if rpm >= CRUISE_MIN_RPM then
+                    cruiseActive = true
+                    targetRpm    = rpm
+                    pid:reset()
+                    print("Cruise ON target=" .. math.floor(rpm) .. " RPM")
+                else
+                    print("Cruise: RPM too low (" .. math.floor(rpm) .. ")")
+                end
+            else
+                disengageCruise()
+            end
+        elseif cruiseActive then
+            if btnStable == BTN_INCREASE then
+                targetRpm = targetRpm + RPM_STEP
+            elseif btnStable == BTN_DECREASE then
+                targetRpm = math.max(CRUISE_MIN_RPM, targetRpm - RPM_STEP)
+            end
+            pid:reset()
+            print("Cruise target=" .. math.floor(targetRpm) .. " RPM")
+        end
+    end
+    btnPrev = btnStable
+
+    -- ---- auto-disengage ----
+    if cruiseActive then
+        local brake = getOutput("brakePedalState")
+        if (brake ~= nil and brake > 0) then
+            print("Cruise OFF: brake")
+            disengageCruise()
+        elseif rpm > CRUISE_MAX_RPM then
+            print("Cruise OFF: RPM " .. math.floor(rpm))
+            disengageCruise()
+        end
+    end
+
+    -- ---- ETB PI control ----
+    if cruiseActive then
+        local adj = pid:get(targetRpm, rpm)
+        setEtbAdd(adj)
+        setLuaGauge(1, adj)
+        setLuaGauge(2, targetRpm)
+    else
+        setEtbAdd(0)
+    end
+
+    -- ---- LED ----
+    local clt = getSensor("Clt")
+    local fault = clt ~= nil and clt > CLT_FAULT_TEMP
+    local stopped = rpm == 0
+
+    local duty
+    if fault then
+        if blinkTimer:getElapsedSeconds() >= BLINK_HALF then
+            blinkOn = not blinkOn
+            blinkTimer:reset()
+        end
+        duty = blinkOn and 1.0 or 0.0
+    elseif stopped then
+        blinkOn = false ; blinkTimer:reset()
+        duty = 1.0
+    elseif cruiseActive then
+        blinkOn = false ; blinkTimer:reset()
+        duty = 0.5
+    else
+        blinkOn = false ; blinkTimer:reset()
+        duty = 0.0
+    end
+
+    setPwmDuty(0, duty)
+end