Reader message processing functions.

stid_readers/core.py

@@ -0,0 +1,74 @@
+# -*- coding: utf-8 -*-
+'''
+    librfid - RFID EPC Class 1 Gen2 / ISO/IEC 18000-6C compliant library
+
+    Copyright (C) 2013  Mikael Ates
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as
+    published by the Free Software Foundation, either version 3 of the
+    License, or (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+
+    Functions to parse reader command response content.
+'''
+
+
+from _exceptions import MalformedDataError, BadParameterException
+from utils import get_integer_on_two_bytes
+
+
+def get_rfsettings(response):
+    '''
+        Parse response content of 'Get_RFSettings' command.
+
+        Return a list of dict describing logic ports of the reader.
+    '''
+    if not response.data:
+        raise MalformedDataError('Data content is malformed.')
+    if len(response.data) != 64:
+        raise MalformedDataError('Data content is malformed.')
+    logic_ports = list()
+    for i in range(0, 16):
+        logic_port = dict()
+        logic_port['ScanDelay'] = int(response.data[i * 4:(i * 4) + 2]
+            .encode('hex'), 16) * 10  # 0 ms ≤ ScanDelay ≤ 655350 ms ()
+        power_ant_nb = int(response.data[(i * 4) + 2:(i * 4) + 4]
+            .encode('hex'), 16)
+        logic_port['AntNb'] = power_ant_nb & 0x000f
+        logic_port['PowerAnt'] = (power_ant_nb >> 4) / 10
+            #[0E6h ≤ PowerAnt ≤ 136h] soit [23 dBm ≤ PowerAnt ≤ 31 dBm] (URF)
+        logic_ports.append(logic_port)
+    return logic_ports
+
+
+def set_rfsettings(logic_ports):
+    '''
+        Parse response content of 'Get_RFSettings' command.
+
+        Return a string representing the data from a list of dict describing
+        logic ports of the reader..
+    '''
+    data = ''
+    i = 0
+    for logic_port in logic_ports:
+        if logic_port['ScanDelay'] > 655350 or logic_port['PowerAnt'] > 31:
+            raise BadParameterException('One bad parameter for logic port '
+                '%s: ScanDelay %s PowerAnt %s'
+                % (i, logic_port['ScanDelay'], logic_port['PowerAnt']))
+        data += get_integer_on_two_bytes(logic_port['ScanDelay'] / 10)
+        power_ant_nb = (logic_port['PowerAnt'] * 10) << 4
+        power_ant_nb |= logic_port['AntNb']
+        data += get_integer_on_two_bytes(power_ant_nb)
+        i += 1
+    for _ in range(i, 16):
+        data += '\x00\x00\x00\x00'
+    return data