Читаем SDS011 PM2.5

uart.setup(2, 9600, 8, uart.PARITY_NONE, uart.STOPBITS_1, {tx = 17, rx = 16})
uart.start(2)
local d25 = 0
local d10 = 0

local gotRAW = {}
local startUART = false

local function ptrANSW()
    local crc = 0
    for i = 3, 8 do crc = crc  + gotRAW[i] end 
    crc = bit.band(crc, 0xFF) 
    -- print(string.format('\t\tcrc = %02X',crc))
    if crc ~= gotRAW[9] then print('Bad CRC'); gotRAW = {}; startUART = false return end

    d25 = ((gotRAW[4]*256 ) + gotRAW[3])/10
    d10 = ((gotRAW[6]*256 ) + gotRAW[5])/10
    print('\n\t\t\tPM2.5 = '..d25..' μg/m3,  d10 = '.. PM10..' μg/m3')

    gotRAW = {}
    startUART = false
    -- dofile('analizeMTRF.lua')
end

uart.on(2,"data",1,
    function(data)
        local bt = string.byte(data, 1)
        -- print(string.format("bt = %02X", bt))
        if startUART == false and bt ~= 0xAA then return
        elseif startUART == false then startUART = true end
        gotRAW[#gotRAW+1] = bt
        if gotRAW[2] and gotRAW[2] ~= 0xC0 then gotRAW = {}; startUART = false end
        if #gotRAW == 10 then ptrANSW() end
end, 0)