iota2str

function table2str(t)
    local function serialize(tbl)
        local tmp = {}
        for k, v in pairs(tbl) do
            local k_type = type(k)
            local v_type = type(v)
            local key = (k_type == "string" and "[\"" .. k .. "\"]=") or (k_type == "number" and "")
            local value = (v_type == "table" and serialize(v)) or (v_type == "boolean" and tostring(v)) or (v_type == "string" and "\"" .. v .. "\"") or (v_type == "number" and v)
            tmp[#tmp + 1] = key and value and tostring(key) .. tostring(value) or nil
        end
        if table.maxn(tbl) == 0 then
            return "\n[\"\"] = {" .. table.concat(tmp, ",") .. "},"
        else
            return "[" .. table.concat(tmp, "") .. "\n]"
        end
    end
    assert(type(t) == "table")
    return serialize(t)
end

dev = peripheral.find("focal_port")
d = dev.readIota()
str = table2str(d)
f = io.open("data","w")
f.write(f,str)
f.close(f)