From 0f203f32c35c2ff7bcc16178555bd4b8007016cf Mon Sep 17 00:00:00 2001 From: Martin Han Date: Mon, 20 Apr 2015 19:43:24 +0800 Subject: [PATCH] Resuce RAM Usage --- lua_modules/dht_lib/dht_lib.lua | 149 ++++++++++++++------------------ 1 file changed, 66 insertions(+), 83 deletions(-) diff --git a/lua_modules/dht_lib/dht_lib.lua b/lua_modules/dht_lib/dht_lib.lua index 4fb60ae3..97823455 100644 --- a/lua_modules/dht_lib/dht_lib.lua +++ b/lua_modules/dht_lib/dht_lib.lua @@ -15,8 +15,6 @@ --AM2320 Not Test yet --Output format-> Real temperature times 10(or DHT22 will miss it float part in Int Version) ---For example, the data read form DHT2x is 24.3 degree C, and the output will be 243 ----------------the data read form DHT1x is 27 degree C, and the output will be 270 --==========================Module Part====================== local moduleName = ... local M = {} @@ -42,8 +40,6 @@ local function read(pin) bitStream[j] = 0 end - - -- Step 1: send out start signal to DHT22 gpio.mode(pin, gpio.OUTPUT) gpio.write(pin, gpio.HIGH) @@ -62,7 +58,7 @@ local function read(pin) while (gpio_read(pin) == 0 ) do end c=0 while (gpio_read(pin) == 1 and c < 500) do c = c + 1 end - + -- Step 3: DHT22 send data for j = 1, 40, 1 do while (gpio_read(pin) == 1 and bitlength < 10 ) do @@ -74,70 +70,78 @@ local function read(pin) while (gpio_read(pin) == 0) do end end end ----------------------------Convert the bitStream into Number through DHT11 Ways-------------------------- -local function bit2DHT11() ---As for DHT11 40Bit is consisit of 5Bytes ---First byte->Humidity Data's Int part ---Sencond byte->Humidity Data's Float Part(Which should be empty) ---Third byte->Temp Data;s Intpart ---Forth byte->Temp Data's Float Part(Which should be empty) ---Fifth byte->SUM Byte, Humi+Temp - local checksum = 0 - local checksumTest - --DHT data acquired, process. + +---------------------------Check out the data-------------------------- +----Auto Select the DHT11/DHT22 By check the byte[1] && byte[3] ------- +---------------Which is empty when using DHT11------------------------- +function M.read(pin) + read(pin) + + local byte_0 = 0 + local byte_1 = 0 + local byte_2 = 0 + local byte_3 = 0 + local byte_4 = 0 + for i = 1, 8, 1 do -- Byte[0] if (bitStream[i] > 3) then - humidity = humidity + 2 ^ (8 - i) + byte_0 = byte_0 + 2 ^ (8 - i) end end + + for i = 1, 8, 1 do -- Byte[1] + if (bitStream[i+8] > 3) then + byte_1 = byte_1 + 2 ^ (8 - i) + end + end + for i = 1, 8, 1 do -- Byte[2] - if (bitStream[i + 16] > 3) then - temperature = temperature + 2 ^ (8 - i) - end - end - for i = 1, 8, 1 do --Byte[4] - if (bitStream[i + 32] > 3) then - checksum = checksum + 2 ^ (8 - i) + if (bitStream[i+16] > 3) then + byte_2 = byte_2 + 2 ^ (8 - i) end end - if(checksum ~= humidity+temperature) then - humidity = nil - temperature = nil - else - humidity = humidity *10 -- In order to universe the DHT22 - temperature = temperature *10 + for i = 1, 8, 1 do -- Byte[3] + if (bitStream[i+24] > 3) then + byte_2 = byte_2 + 2 ^ (8 - i) + end + end + + for i = 1, 8, 1 do -- Byte[4] + if (bitStream[i+32] > 3) then + byte_4 = byte_4 + 2 ^ (8 - i) + end end - -end ----------------------------Convert the bitStream into Number through DHT22 Ways-------------------------- -local function bit2DHT22() ---As for DHT22 40Bit is consisit of 5Bytes ---First byte->Humidity Data's High Bit ---Sencond byte->Humidity Data's Low Bit(And if over 0x8000, use complement) ---Third byte->Temp Data's High Bit ---Forth byte->Temp Data's Low Bit ---Fifth byte->SUM Byte - local checksum = 0 - local checksumTest - --DHT data acquired, process. - for i = 1, 16, 1 do - if (bitStream[i] > 3) then - humidity = humidity + 2 ^ (16 - i) + if byte_1==0 and byte_3 == 0 then + ---------------------------Convert the bitStream into Number through DHT11's Way-------------------------- + --As for DHT11 40Bit is consisit of 5Bytes + --First byte->Humidity Data's Int part + --Sencond byte->Humidity Data's Float Part(Which should be empty) + --Third byte->Temp Data;s Intpart + --Forth byte->Temp Data's Float Part(Which should be empty) + --Fifth byte->SUM Byte, Humi+Temp + + if(byte_4 ~= byte_0+byte_2) then + humidity = nil + temperature = nil + else + humidity = byte_0 *10 -- In order to universe with the DHT22 + temperature = byte_2 *10 end - end - for i = 1, 16, 1 do - if (bitStream[i + 16] > 3) then - temperature = temperature + 2 ^ (16 - i) - end - end - for i = 1, 8, 1 do - if (bitStream[i + 32] > 3) then - checksum = checksum + 2 ^ (8 - i) - end - end + + else ---------------------------Convert the bitStream into Number through DHT22's Way-------------------------- + --As for DHT22 40Bit is consisit of 5Bytes + --First byte->Humidity Data's High Bit + --Sencond byte->Humidity Data's Low Bit(And if over 0x8000, use complement) + --Third byte->Temp Data's High Bit + --Forth byte->Temp Data's Low Bit + --Fifth byte->SUM Byte + + humidity = byte_0 * 256 + byte_1 + temperature = byte_2 * 256 + byte_3 + checksum = byte_4 checksumTest = (bit.band(humidity, 0xFF) + bit.rshift(humidity, 8) + bit.band(temperature, 0xFF) + bit.rshift(temperature, 8)) checksumTest = bit.band(checksumTest, 0xFF) @@ -151,35 +155,14 @@ local function bit2DHT22() if (checksumTest - checksum >= 1) or (checksum - checksumTest >= 1) then humidity = nil end -end ----------------------------Check out the data-------------------------- -----Auto Select the DHT11/DHT22 by checking the byte[1]==0 && byte[3]==0 --- ----------------Which is empty when using DHT11------------------------- -function M.read(pin) - - read(pin) - - local byte_1 = 0 - local byte_2 = 0 - - for i = 1, 8, 1 do -- Byte[1] - if (bitStream[i+8] > 3) then - byte_1 = byte_1 + 2 ^ (8 - i) - end end - for i = 1, 8, 1 do -- Byte[1] - if (bitStream[i+24] > 3) then - byte_2 = byte_2 + 2 ^ (8 - i) - end - end - - if byte_1==0 and byte_2 == 0 then - bit2DHT11() - else - bit2DHT22() - end + byte_0 = nil + byte_1 = nil + byte_2 = nil + byte_3 = nil + byte_4 = nil end --------------API for geting the data out------------------