Joystick Lua library and example code (#2710)

lua_modules/joystick/joystick.lua

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+-- ChiliPeppr Joystick controller
+-- Used to control analog joysticks that are implemented just using
+-- variable resistors where you feed in 3.3v and get out a variable voltage
+-- based on position of the joystick. Joysticks like the Playstation portable
+-- or Xbox joysticks work this way and are readily available on Amazon, Ebay,
+-- or Aliexpress.
+--
+-- Working example of using this library:
+-- https://www.youtube.com/watch?v=ITgh5epyPRk
+--
+-- Visit http://chilipeppr.com/esp32
+-- By John Lauer
+--
+-- There is no license needed to use/modify this software. It is given freely
+-- to the open source community. Modify at will.
+-- 
+-- To use:
+-- joystick = require("joystick")
+-- joystick.on("xy", function(x, y)
+--   print("Got xy change. x:", x, "y:", y)
+-- end)
+-- joystick.on("x", function(x)
+--   print("Got x change. x:", x)
+-- end)
+-- joystick.on("y", function(y)
+--   print("Got y change. y:", y)
+-- end)
+-- joystick.on("xcenter", function()
+--   print("Got x center")
+-- end)
+-- joystick.on("ycenter", function()
+--   print("Got y center")
+-- end)
+-- joystick.on("button", function(val)
+--   print("Got button:", val)
+-- end)
+-- joystick.init()
+
+-- For test/debug
+-- if m.tmr then m.tmr:stop(); m.tmr:unregister() end 
+
+local m = {}
+-- m = {}
+
+m.pinAdcX = 6 -- ADC 6: GPIO34
+-- m.pinAdcY = 3 -- ADC 3: GPIO39
+-- m.pinAdcY = 7 -- ADC 7: GPIO35
+m.pinAdcY = 5 -- ADC 5: GPIO33
+-- m.pinSwitch = 18
+m.pinSwitch = 32
+
+-- For TTGO
+-- m.centerX = 1850
+-- m.centerXMin = 1800
+-- m.centerXMax = 1915
+-- m.centerY = 1850
+-- m.centerYMin = 1800
+-- m.centerYMax = 1915
+
+-- For Wemos battery powered
+m.centerX = 1800
+m.centerXMin = 1700
+m.centerXMax = 1870
+m.centerY = 1800
+m.centerYMin = 1700
+m.centerYMax = 1870
+
+
+m.isInitted = false
+m.tmr = tmr.create()
+
+---
+-- @name init
+-- @description Call this first to setup your ADC ports and button port. You
+-- need to connect X to ADC 6: GPIO34, Y to ADC5: GPIO33, and the button to GPIO32.
+-- If you need to use alternate ports you should change the code in joystick.lua.
+-- Also, 11db attenuation is turned on by default because it is the best
+-- performance for analog joysticks. If you are finding a broader range of voltage
+-- is coming back from your joystick, adjust the attenuation in the init() method.
+-- @returns nil
+function m.init()
+  
+  if m.isInitted then
+    return
+  end
+  
+  print("Initting joystick pins. X: " .. m.pinAdcX .. ", Y: " .. m.pinAdcY .. ", Switch: " .. m.pinSwitch)
+  
+  -- Initialise the pins
+  gpio.config( { gpio=m.pinSwitch, dir=gpio.IN, pull=gpio.PULL_UP } )
+  m.startSwitchInterrupt()
+  
+  -- adc.setwidth(adc.ADC1, 9)  -- read 9 bit on ADC
+  adc.setwidth(adc.ADC1, 12)  -- read 12 bit on ADC
+  adc.setup(adc.ADC1, m.pinAdcX, adc.ATTEN_11db    )
+  adc.setup(adc.ADC1, m.pinAdcY, adc.ATTEN_11db    )
+  
+  m.tmr:alarm(250, tmr.ALARM_AUTO, function()
+    m.readXY()
+    -- m.readY()
+    -- m.readX()
+  end)
+  
+  m.isInitted = true
+  
+end
+
+m.onX = nil
+m.onXCenter = nil
+m.onY = nil
+m.onYCenter = nil
+m.onXY = nil
+m.onButton = nil 
+---
+-- @name on
+-- @description Attach to the callback events available from this joystick library
+-- @param event_name A string of the event you want a callback on. "x", "y", "xy", "xcenter", "ycenter", "button"
+-- @param func The callback to receive after the event
+-- @returns nil
+function m.on(event_name, func)
+  if event_name == "x" then 
+    m.onX = func 
+  elseif event_name == "xcenter" then
+    m.onXCenter = func 
+  elseif event_name == "y" then 
+    m.onY = func 
+  elseif event_name == "ycenter" then
+    m.onYCenter = func
+  elseif event_name == "xy" then
+    m.onXY = func
+  elseif event_name == "button" then 
+    m.onButton = func 
+  end 
+end  
+
+m.lastX = 0
+function m.readX()
+  local val = adc.read(adc.ADC1, m.pinAdcX)
+  if m.lastX == val then return end
+  m.lastX = val
+  print("X: " .. val)
+  if m.onX then m.onX(val) end 
+end
+
+m.lastY = 0
+function m.readY()
+  local val = adc.read(adc.ADC1, m.pinAdcY)
+  if m.lastY == val then return end
+  m.lastY = val
+  print("Y: " .. val)
+  if m.onY then m.onY(val) end 
+end
+
+m.lastXWasCenter = true
+m.lastYWasCenter = true
+function m.readXY()
+  local valX = adc.read(adc.ADC1, m.pinAdcX)
+  local valY = adc.read(adc.ADC1, m.pinAdcY)
+  
+  -- if x or y is new value then send xy update
+  local isXYUpdated = false
+  
+  -- do some level setting for center point
+  if valX >= m.centerXMin and valX <= m.centerXMax then 
+    -- consider it a center point
+    -- valX = m.centerX
+    
+    -- see if last X was center, and if so ignore 
+    if m.lastXWasCenter then
+      -- do nothing
+    else 
+    
+      -- last x was not center, so fire off event
+      m.lastXWasCenter = true
+      if m.onXCenter then 
+        node.task.post(node.task.LOW_PRIORITY, function()
+          m.onXCenter(m.centerX) 
+        end)
+      end
+    end 
+    
+  else 
+    -- x is not on center, so fire event
+    m.lastXWasCenter = false
+    isXYUpdated = true
+    if m.onX then 
+      node.task.post(node.task.LOW_PRIORITY, function()
+        m.onX(valX) 
+      end)
+    end
+  end 
+  
+  if valY >= m.centerYMin and valY <= m.centerYMax then 
+    -- consider it a center point
+    -- valY = m.centerY
+    -- see if last Y was center, and if so ignore 
+    if m.lastYWasCenter then
+      -- do nothing
+    else
+    
+      -- last x was not center, so fire off event
+      m.lastYWasCenter = true
+      if m.onYCenter then 
+        node.task.post(node.task.LOW_PRIORITY, function()
+          m.onYCenter(m.centerY) 
+        end)
+      end
+    end 
+    
+  else 
+    -- y is not on center, so fire event
+    m.lastYWasCenter = false
+    isXYUpdated = true
+    if m.onY then 
+      node.task.post(node.task.LOW_PRIORITY, function()
+        m.onY(valY) 
+      end)
+    end
+  end
+  
+  if isXYUpdated then
+    if m.onXY then 
+      node.task.post(node.task.LOW_PRIORITY, function()
+        m.onXY(valX, valY) 
+      end)
+    end
+  end
+  
+  -- print("X: " .. valX .. ", Y: " .. valY)
+  
+end
+
+function m.readSwitch()
+  local val = gpio.read(m.pinSwitch)
+  print("Switch: ", val)
+  if m.onButton then m.onButton(val) end
+end
+
+function m.startSwitchInterrupt()
+  gpio.trig(m.pinSwitch, gpio.INTR_UP_DOWN, m.onSwitchInterrupt)
+  print("Set interrupt for switch.")
+end 
+
+m.lastSwitchVal = 0
+function m.onSwitchInterrupt(pin, level)
+  if level == m.lastSwitchVal then return end 
+  m.lastSwitchVal = level
+  print("Got switch interrupt. pin: ", pin, ", level: ", level)
+end
+
+-- m.init()
+
+return m 
+
+
+                                

lua_modules/joystick/joystick_test.lua

@@ -0,0 +1,44 @@
+-- ChiliPeppr Joystick controller
+-- Used to control analog joysticks that are implemented just using
+-- variable resistors where you feed in 3.3v and get out a variable voltage
+-- based on position of the joystick. Joysticks like the Playstation portable
+-- or Xbox joysticks work this way and are readily available on Amazon, Ebay,
+-- or Aliexpress.
+--
+-- Working example of using this library:
+-- https://www.youtube.com/watch?v=ITgh5epyPRk
+--
+-- Visit http://chilipeppr.com/esp32
+-- By John Lauer
+--
+-- There is no license needed to use/modify this software. It is given freely
+-- to the open source community. Modify at will.
+-- 
+joystick = require("joystick")
+
+joystick.on("xy", function(x, y)
+  print("Got xy change. x:", x, "y:", y)
+end)
+
+-- joystick.on("x", function(x)
+--   print("Got x change. x:", x)
+-- end)
+
+-- joystick.on("y", function(y)
+--   print("Got y change. y:", y)
+-- end)
+
+joystick.on("xcenter", function()
+  print("Got x center")
+end)
+
+joystick.on("ycenter", function()
+  print("Got y center")
+end)
+
+joystick.on("button", function(val)
+  print("Got button:", val)
+end)
+
+joystick.init()
+