Diff: radio_sensor.cpp

Revision:

0:1441b10e38a6

Child:

2:0417c5cdceaf

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/radio_sensor.cpp	Thu Jan 04 03:42:09 2018 +0000
@@ -0,0 +1,203 @@
+/*
+** Because we're working with relatively small packet sizes (~10 bytes) each set
+** of sensor data must be split up and sent in multiple packets. To keep track
+** of these packets they will each contain a id which indicates the set of
+** sensor data they belong to and a sequence number which indicates their
+** position in that set of sensor data. The first packet of each set will also
+** include and additional field which will be the number of packets to expect.
+** This will make it easy to determine if packets have been dropped and
+** therefore if the set of sensor data will be valid.
+** The packet structure:
+** [id (1 byte)] [sequence (1 byte)] [expected packets (1 byte)] [data (n - 3 bytes)]
+** [id (1 byte)] [sequence (1 byte)] [data (n - 2 bytes)]
+** Note:
+**       The ID is allowed to and will be expected to overflow back to 0.
+*/
+
+
+#include "radio_sensor.h"
+
+
+mDot* dot = NULL;
+
+// Network settings.
+static uint8_t radio_network_address[]     = {0x65, 0x34, 0x03, 0x04};
+static uint8_t radio_network_session_key[] = {0x23, 0x45, 0x03, 0x04, 0x01, 0x02, 0x03, 0x04, 0x01, 0x02, 0x03, 0x04, 0x01, 0x02, 0x03, 0x04};
+static uint8_t radio_data_session_key[]    = {0xF0, 0x34, 0x03, 0x04, 0x01, 0x02, 0x03, 0x04, 0x01, 0x02, 0x03, 0x04, 0x01, 0x02, 0x03, 0x04};
+
+static uint8_t radio_packet_current_id;
+
+
+extern int8_t radio_sensor_init(enum mts::MTSLog::logLevel logging_level) {
+    uint8_t radio_data_rate, radio_power, radio_frequency_band;
+    uint32_t radio_frequency;
+    lora::ChannelPlan* plan;
+    
+    
+    radio_packet_current_id = 0;
+    
+    
+    // Configure the logging level and instatiate the mDot with the correct channel plan.
+    mts::MTSLog::setLogLevel(logging_level);
+    
+#if RADIO_CHANNEL_PLAN == CP_US915
+    plan = new lora::ChannelPlan_US915();
+#elif RADIO_CHANNEL_PLAN == CP_AU915
+    plan = new lora::ChannelPlan_AU915();
+#elif RADIO_CHANNEL_PLAN == CP_EU868
+    plan = new lora::ChannelPlan_EU868();
+#elif RADIO_CHANNEL_PLAN == CP_KR920
+    plan = new lora::ChannelPlan_KR920();
+#elif RADIO_CHANNEL_PLAN == CP_AS923
+    plan = new lora::ChannelPlan_AS923();
+#elif RADIO_CHANNEL_PLAN == CP_AS923_JAPAN
+    plan = new lora::ChannelPlan_AS923_Japan();
+#elif RADIO_CHANNEL_PLAN == CP_IN865
+    plan = new lora::ChannelPlan_IN865();
+#endif
+    assert(plan);
+    
+    dot = mDot::getInstance(plan);
+    assert(dot);
+    dot->setLogLevel(logging_level);
+    
+    // Return the mdot to a known state.
+    dot->resetConfig();
+    
+    // Configure MDOT network settings.
+    if (dot->getJoinMode() != mDot::PEER_TO_PEER) {
+        logInfo("changing network join mode to PEER_TO_PEER");
+        if (dot->setJoinMode(mDot::PEER_TO_PEER) != mDot::MDOT_OK) {
+            logError("failed to set network join mode to PEER_TO_PEER");
+        }
+    }
+    
+    radio_frequency_band = dot->getFrequencyBand();
+    switch (radio_frequency_band) {
+        case lora::ChannelPlan::EU868_OLD:
+        case lora::ChannelPlan::EU868:
+            // 250kHz channels achieve higher throughput
+            // DR_6 : SF7 @ 250kHz
+            // DR_0 - DR_5 (125kHz channels) available but much slower
+            radio_frequency = 869850000;
+            radio_data_rate = lora::DR_6;
+            // the 869850000 frequency is 100% duty cycle if the total power is under 7 dBm - tx power 4 + antenna gain 3 = 7
+            radio_power = 4;
+            break;
+
+        case lora::ChannelPlan::US915_OLD:
+        case lora::ChannelPlan::US915:
+        case lora::ChannelPlan::AU915_OLD:
+        case lora::ChannelPlan::AU915:
+            // 500kHz channels achieve highest throughput
+            // DR_8 : SF12 @ 500kHz
+            // DR_9 : SF11 @ 500kHz
+            // DR_10 : SF10 @ 500kHz
+            // DR_11 : SF9 @ 500kHz
+            // DR_12 : SF8 @ 500kHz
+            // DR_13 : SF7 @ 500kHz
+            // DR_0 - DR_3 (125kHz channels) available but much slower
+            radio_frequency = 915500000;
+            radio_data_rate = lora::DR_13;
+            // 915 bands have no duty cycle restrictions, set tx power to max
+            radio_power = 20;
+            break;
+
+        case lora::ChannelPlan::AS923:
+        case lora::ChannelPlan::AS923_JAPAN:
+            // 250kHz channels achieve higher throughput
+            // DR_6 : SF7 @ 250kHz
+            // DR_0 - DR_5 (125kHz channels) available but much slower
+            radio_frequency = 924800000;
+            radio_data_rate = lora::DR_6;
+            radio_power = 16;
+            break;
+
+        case lora::ChannelPlan::KR920:
+            // DR_5 : SF7 @ 125kHz
+            radio_frequency = 922700000;
+            radio_data_rate = lora::DR_5;
+            radio_power = 14;
+            break;
+
+        default:
+            while (true) {
+                logFatal("no known channel plan in use - extra configuration is needed!");
+                wait(5);
+            }
+    }
+    
+    update_peer_to_peer_config(radio_network_address, radio_network_session_key, radio_data_session_key, radio_frequency, radio_data_rate, radio_power);
+    
+    // Save changes to configuration.
+    logInfo("saving configuration");
+    if (!dot->saveConfig()) {
+        logError("failed to save configuration");
+    }
+    
+    // Join network if not joined.
+    if (!dot->getNetworkJoinStatus()) {
+        join_network();
+    }
+
+    // Display configuration.
+    display_config();
+    
+    return 0;
+}
+
+extern int8_t radio_sensor_transmit(struct sensor_data_raw data) {
+    uint8_t packet_length_max, packet_seq, packets_required;
+    uint8_t tx_buffer[sizeof(struct sensor_data_raw)];
+    uint32_t packet_length_data, tx_buffer_size;
+    std::vector<uint8_t> radio_packet;
+    
+    packet_length_max = dot->getMaxPacketLength();
+    logDebug("The maximum packet length is %i.", packet_length_max);
+    
+    if(packet_length_max < 3) {
+        logError("The packet length allowed by the mDot is too small (%u).", packet_length_max);
+        return -1;
+    }
+    
+    
+    packet_length_data = packet_length_max - 2;
+    tx_buffer_size = sizeof(struct sensor_data_raw);
+    // This performs an integer division and round up operation.
+    packets_required = (tx_buffer_size + packet_length_data - 1) / packet_length_data;
+    
+    // Turn the sensor data into a stream of bytes.
+    serialize_sensor_to_bytes(data, tx_buffer);
+    
+    packet_seq = 0;
+    
+    // For the first 
+    //radio_packet.push_back(radio_packet_current_id);
+    //radio_packet.push_back(packet_seq);
+    //radio_packet.push_back(packets_required);
+    
+    for(uint32_t i = 0; i < tx_buffer_size; i++) {
+        // Current packet finished constructing, send it and begin again.
+        if(radio_packet.size() >= packet_length_max) {
+            send_data(radio_packet);
+            radio_packet.clear();
+            
+            packet_seq++;
+            
+            radio_packet.push_back(radio_packet_current_id);
+            radio_packet.push_back(packet_seq);
+        }
+        
+        radio_packet.push_back(tx_buffer[i]);
+    }
+    
+    // Send the last packet. This will happen if the data is not divisible by the number of required packets.
+    if(radio_packet.size() > 0) {
+        send_data(radio_packet);
+        radio_packet.clear();
+    }
+    
+    radio_packet_current_id++;
+    
+    return 0;
+}
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