Documented changes to rovecomm packet size and changed said size to n…

…umbers listed in the read me
MissouriMRDT · Feb 22, 2022 · 02a8ccd · 02a8ccd
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Showing 4 changed files with 19 additions and 6 deletions.
diff --git a/README.md b/README.md
@@ -14,5 +14,9 @@ The RoveComm udp packet header is 5 bytes long:
 
 The packet then countains a data_count number of data elements. The size of each element depends on the data type.
 
+Due to memory limitations, the Tiva can only support 21,845 uint8_ts, 10,922 uint16_ts, 5461 uint32_ts, 5461 floats, or 2730 doubles at once.
+
+Due to memory limitations, the Teensy can only support 32,767 uint8_ts, 16,383 uint16_ts, 8,191 uint32_ts, 8,191 floats, or 4,095 doubles at once.
+
 ## Use
 Examples of how to implement RoveComm on the Tiva C Microcontroller and Teensy 4.1 are [here](https://github.com/MissouriMRDT/RoveComm/tree/dev/examples).
diff --git a/examples/RoveCommUdp/RoveCommUdp.ino b/examples/RoveCommUdp/RoveCommUdp.ino
@@ -38,9 +38,6 @@ void loop()
   {
     case RC_DRIVEBOARD_DRIVEINDIVIDUAL_DATA_ID:
       Serial.println("We received an individual wheel drive command");
-      char* sped;
-      sped = (char*)packet.data;
-      Serial.println(sped[0]);
       break;
     case RC_DRIVEBOARD_DRIVELEFTRIGHT_DATA_ID:
       //cast the packet to the correct data type

diff --git a/src/RoveCommPacket.cpp b/src/RoveCommPacket.cpp
@@ -273,7 +273,11 @@ namespace roveware
     uint16_t data_count = (header[3] << 8)
                        | header[4];
     data_type_t data_type  =  (data_type_t)header[5];
-    char bytes[(ROVECOMM_PACKET_MAX_DATA_COUNT/257)*8];
+    #if defined(ENERGIA)
+    char data[ROVECOMM_PACKET_MAX_DATA_COUNT*sizeof(uint8_t)/3];  //Tiva can only support 21,000 uint8_t at once due to memory issues
+    #elif defined(ARDUINO) && (ARDUINO>100)
+    char data[ROVECOMM_PACKET_MAX_DATA_COUNT*sizeof(uint8_t)/2];  //Teensy can only support 32,000 uint8_t at once due to memory issues
+    #endif
 
     //Unpack data based on data_type
     if(data_type ==  INT32_T)

diff --git a/src/RoveCommPacket.h b/src/RoveCommPacket.h
@@ -25,7 +25,11 @@ struct rovecomm_packet
   uint16_t data_id;
   uint16_t data_count;
   uint8_t data_type;
-  char data[(ROVECOMM_PACKET_MAX_DATA_COUNT/257)*8];
+  #if defined(ENERGIA)
+  char data[ROVECOMM_PACKET_MAX_DATA_COUNT/3*sizeof(uint8_t)]; //Tiva can only support 21,000 uint8_t at once due to memory issues
+  #elif defined(ARDUINO) && (ARDUINO>100)
+  char data[ROVECOMM_PACKET_MAX_DATA_COUNT/2*sizeof(uint8_t)];  //Teensy can only support 32,000 uint8_t at once due to memory issues
+  #endif
 };  
 
 //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
@@ -44,7 +48,11 @@ namespace roveware
   //Carrys Udp packet data
   struct _packet
   {
-    uint8_t bytes[ROVECOMM_PACKET_HEADER_SIZE + sizeof(uint8_t) * ROVECOMM_PACKET_MAX_DATA_COUNT];
+    #if defined(ENERGIA)
+    uint8_t bytes[ROVECOMM_PACKET_HEADER_SIZE + sizeof(uint8_t) * ROVECOMM_PACKET_MAX_DATA_COUNT/3];  //Tiva can only support 21,000 uint8_t at once due to memory issues
+    #elif defined(ARDUINO) && (ARDUINO>100)
+    uint8_t bytes[ROVECOMM_PACKET_HEADER_SIZE + sizeof(uint8_t) * ROVECOMM_PACKET_MAX_DATA_COUNT/2];  //Teensy can only support 32,000 uint8_t at once due to memory issues
+    #endif
   };
 
   struct _packet        packPacket(const uint16_t data_id, const uint16_t data_count, const data_type_t data_type, const void* data);