MCP23017 module refactorings to save some heap (#3317)
* mcp23017: functions to metatable Avoids closures for each module. * mcp23017: inline constants Saves nearly half a kilobyte of heap.
This commit is contained in:
Nathaniel Wesley Filardo
Marcel Stör
parent
7f30381301
commit
0cafaca4cb
|
|
@ -1,62 +1,40 @@
|
|||
--[[
|
||||
This Lua module provides access to the MCP23017 module.
|
||||
This Lua module provides access to the MCP23017 module.
|
||||
|
||||
The MCP23017 is a port expander and provides 16 channels for inputs and outputs.
|
||||
Up to 8 devices (128 channels) are possible by the configurable address (A0 - A2 Pins).
|
||||
The MCP23017 is a port expander and provides 16 channels for inputs and
|
||||
outputs. Up to 8 devices (128 channels) are possible by the configurable
|
||||
address (A0 - A2 Pins).
|
||||
|
||||
Due to the 16 channels, 2 bytes are required for switching outputs or reading input signals. These are A and B.
|
||||
A single pin can be set or a whole byte.
|
||||
Due to the 16 channels, 2 bytes are required for switching outputs or
|
||||
reading input signals. These are A and B. A single pin can be set or a
|
||||
whole byte.
|
||||
|
||||
The numbering of the individual pins starts at 0 and ends with 7.
|
||||
The numbers are for each register GPIO A and GPIO B.
|
||||
The numbering of the individual pins starts at 0 and ends with 7. The
|
||||
numbers are for each register GPIO A and GPIO B.
|
||||
|
||||
The module requires `i2c` and `bit` C module built into firmware.
|
||||
The module requires `i2c` and `bit` C module built into firmware.
|
||||
|
||||
@author Marcel P. | Plomi.net
|
||||
@github https://github.com/plomi-net
|
||||
@version 1.0.0
|
||||
For register name <-> number mapping, see the MCP23017 data sheet, table
|
||||
3-1 on page 12 (as of Revision C, July 2016). This module uses the
|
||||
IOCON.BANK=0 numbering (the default) throughout.
|
||||
|
||||
@author Marcel P. | Plomi.net
|
||||
@github https://github.com/plomi-net
|
||||
@version 1.0.0
|
||||
]]
|
||||
|
||||
local i2c, string, issetBit, setBit, clearBit, error =
|
||||
i2c, string, bit.isset, bit.set, bit.clear, error
|
||||
local isINPUT, isGPB, isHIGH = true, true, true
|
||||
|
||||
-- registers (not used registers are commented out)
|
||||
local MCP23017_IODIRA = 0x00
|
||||
local MCP23017_IODIRB = 0x01
|
||||
local MCP23017_DEFVALA = 0x06
|
||||
local MCP23017_DEFVALB = 0x07
|
||||
local MCP23017_GPIOA = 0x12
|
||||
local MCP23017_GPIOB = 0x13
|
||||
--[[
|
||||
local MCP23017_IPOLA = 0x02
|
||||
local MCP23017_IPOLB = 0x03
|
||||
local MCP23017_GPINTENA = 0x04
|
||||
local MCP23017_GPINTENB = 0x05
|
||||
local MCP23017_DEFVALA = 0x06
|
||||
local MCP23017_DEFVALB = 0x07
|
||||
local MCP23017_INTCONA = 0x08
|
||||
local MCP23017_INTCONB = 0x09
|
||||
local MCP23017_IOCON = 0x0A
|
||||
local MCP23017_IOCON2 = 0x0B
|
||||
local MCP23017_GPPUA = 0x0C
|
||||
local MCP23017_GPPUB = 0x0D
|
||||
local MCP23017_INTFA = 0x0E
|
||||
local MCP23017_INTFB = 0x0F
|
||||
local MCP23017_INTCAPA = 0x10
|
||||
local MCP23017_INTCAPB = 0x11
|
||||
local MCP23017_OLATA = 0x14
|
||||
local MCP23017_OLATB = 0x15
|
||||
]]
|
||||
local i2c, string, issetBit, setBit, clearBit =
|
||||
i2c, string, bit.isset, bit.set, bit.clear
|
||||
|
||||
-- metatable
|
||||
local mcp23017 = {
|
||||
INPUT = isINPUT,
|
||||
OUTPUT = not isINPUT,
|
||||
GPA = not isGPB,
|
||||
GPB = isGPB,
|
||||
HIGH = isHIGH,
|
||||
LOW = not isHIGH
|
||||
-- convenience parameter enumeration names
|
||||
INPUT = true,
|
||||
OUTPUT = false,
|
||||
GPA = false,
|
||||
GPB = true,
|
||||
HIGH = true,
|
||||
LOW = false
|
||||
}
|
||||
mcp23017.__index = mcp23017
|
||||
|
||||
|
|
@ -98,13 +76,65 @@ local function checkPinIsInRange(pin)
|
|||
return pin
|
||||
end
|
||||
|
||||
local function reset(address, i2cId)
|
||||
writeByte(address, i2cId, MCP23017_IODIRA, 0xFF)
|
||||
writeByte(address, i2cId, MCP23017_IODIRB, 0xFF)
|
||||
function mcp23017:writeIODIR(bReg, newByte)
|
||||
writeByte(self.address, self.i2cId,
|
||||
bReg and 0x1 --[[IODIRB register]] or 0x0 --[[IODIRA register]], newByte)
|
||||
end
|
||||
|
||||
-- setup device
|
||||
local function setup(address, i2cId)
|
||||
function mcp23017:writeGPIO(bReg, newByte)
|
||||
writeByte(self.address, self.i2cId,
|
||||
bReg and 0x13 --[[GPIOB register]] or 0x12 --[[GPIOA register]], newByte)
|
||||
end
|
||||
|
||||
function mcp23017:readGPIO(bReg)
|
||||
return readByte(self.address, self.i2cId,
|
||||
bReg and 0x13 --[[GPIOB register]] or 0x12 --[[GPIOA register]])
|
||||
end
|
||||
|
||||
-- read pin input
|
||||
function mcp23017:getPinState(bReg, pin)
|
||||
return issetBit(readByte(self.address, self.i2cId,
|
||||
bReg and 0x13 --[[GPIOB register]] or 0x12 --[[GPIOA register]]),
|
||||
checkPinIsInRange(pin))
|
||||
end
|
||||
|
||||
-- set pin to low or high
|
||||
function mcp23017:setPin(bReg, pin, state)
|
||||
local a, i = self.address, self.i2cId
|
||||
local inReq = bReg and 0x13 --[[GPIOB register]] or 0x12 --[[GPIOA register]]
|
||||
local inPin = checkPinIsInRange(pin)
|
||||
local response = readByte(a, i, inReq)
|
||||
writeByte(a, i, inReq,
|
||||
state and setBit(response, inPin) or clearBit(response, inPin))
|
||||
return true
|
||||
end
|
||||
|
||||
-- set mode for a pin
|
||||
function mcp23017:setMode(bReg, pin, mode)
|
||||
local a, i = self.address, self.i2cId
|
||||
local inReq = bReg and 0x1 --[[IODIRB register]] or 0x0 --[[IODIRA register]]
|
||||
local inPin = checkPinIsInRange(pin)
|
||||
local response = readByte(a, i, inReq)
|
||||
writeByte(a, i, inReq,
|
||||
mode and setBit(response, inPin) or clearBit(response, inPin))
|
||||
return true
|
||||
end
|
||||
|
||||
-- reset gpio mode
|
||||
function mcp23017:reset()
|
||||
local a, i = self.address, self.i2cId
|
||||
writeByte(a, i, 0x0 --[[IODIRA register]], 0xFF)
|
||||
writeByte(a, i, 0x1 --[[IODIRB register]], 0xFF)
|
||||
end
|
||||
|
||||
-- setup internal pullup
|
||||
function mcp23017:setInternalPullUp(bReg, iByte)
|
||||
writeByte(self.address, self.i2cId,
|
||||
bReg and 0x7 --[[DEFVALB register]] or 0x6 --[[DEFVALA register]], iByte)
|
||||
end
|
||||
|
||||
return function(address, i2cId)
|
||||
local self = setmetatable({}, mcp23017)
|
||||
|
||||
-- check device address (0x20 to 0x27)
|
||||
if (address < 32 or address > 39) then
|
||||
|
|
@ -113,73 +143,13 @@ local function setup(address, i2cId)
|
|||
|
||||
if (checkDevice(address, i2cId) ~= true) then
|
||||
error("MCP23017 device on " .. string.format('0x%02X', address) .. " not found")
|
||||
else
|
||||
reset(address, i2cId)
|
||||
return 1
|
||||
end
|
||||
end
|
||||
|
||||
return function(address, i2cId)
|
||||
local self = setmetatable({}, mcp23017)
|
||||
self.address = address
|
||||
self.i2cId = i2cId
|
||||
|
||||
if setup(address, i2cId) then
|
||||
self.writeIODIR = function(sf, bReg, newByte) -- luacheck: no unused
|
||||
writeByte(address, i2cId,
|
||||
bReg == isGPB and MCP23017_IODIRB or MCP23017_IODIRA,
|
||||
newByte)
|
||||
end
|
||||
|
||||
self.writeGPIO = function(sf, bReg, newByte) -- luacheck: no unused
|
||||
writeByte(address, i2cId,
|
||||
bReg == isGPB and MCP23017_GPIOB or MCP23017_GPIOA, newByte)
|
||||
end
|
||||
|
||||
self.readGPIO = function(sf, bReg) -- luacheck: no unused
|
||||
return readByte(address, i2cId, -- upvals
|
||||
bReg == isGPB and MCP23017_GPIOB or MCP23017_GPIOA)
|
||||
end
|
||||
|
||||
-- read pin input
|
||||
self.getPinState = function(sf, bReg, pin) -- luacheck: no unused
|
||||
return issetBit(readByte(address, i2cId,
|
||||
bReg == isGPB and MCP23017_GPIOB or MCP23017_GPIOA),
|
||||
checkPinIsInRange(pin))
|
||||
end
|
||||
|
||||
-- set pin to low or high
|
||||
self.setPin = function(sf, bReg, pin, state) -- luacheck: no unused
|
||||
local inReq = bReg == isGPB and MCP23017_GPIOB or MCP23017_GPIOA
|
||||
local inPin = checkPinIsInRange(pin)
|
||||
local response = readByte(address, i2cId, inReq)
|
||||
writeByte(address, i2cId, inReq,
|
||||
state == isHIGH and setBit(response, inPin) or clearBit(response, inPin))
|
||||
return true
|
||||
end
|
||||
|
||||
-- set mode for a pin
|
||||
self.setMode = function(sf, bReg, pin, mode) -- luacheck: no unused
|
||||
local inReq = bReg == isGPB and MCP23017_IODIRB or MCP23017_IODIRA
|
||||
local inPin = checkPinIsInRange(pin)
|
||||
local response = readByte(address, i2cId, inReq)
|
||||
writeByte(address, i2cId, inReq,
|
||||
mode == isINPUT and setBit(response, inPin) or clearBit(response, inPin))
|
||||
return true
|
||||
end
|
||||
|
||||
-- reset gpio mode
|
||||
self.reset = function(sf) -- luacheck: no unused
|
||||
reset(address, i2cId)
|
||||
end
|
||||
|
||||
-- setup internal pullup
|
||||
self.setInternalPullUp = function(sf, bReg, iByte) -- luacheck: no unused
|
||||
writeByte(address, i2cId,
|
||||
bReg == isGPB and MCP23017_DEFVALB or MCP23017_DEFVALA, iByte)
|
||||
end
|
||||
|
||||
return self
|
||||
end
|
||||
return nil
|
||||
self:reset()
|
||||
return self
|
||||
end
|
||||
|
||||
|
||||
|
|
|
|||
Loading…
Reference in New Issue