Mavlink Decoding

Hi,I am trying to decode mavlink message sent from GCS. This is the code I am using. The autopilot board is based on PSoC5 processor.void comm_receive(){mavlink_message_t msg;mavlink_status_t status;p=UART_2_GetRxBufferSize();for(q=0;q

charc= UART_2_GetChar();if(mavlink_parse_char(MAVLINK_COMM_0, charc, &msg, &status)){switch(msg.msgid){case (0xAD):{UART_1_PutString("Data Stream ");UART_1_PutCRLF(0X0D);}case (0xA6):{UART_1_PutString("Radio ");UART_1_PutCRLF(0X0D);}case MAVLINK_MSG_ID_MISSION_ACK:{UART_1_PutString("Mission ack ");UART_1_PutCRLF(0X0D);}case MAVLINK_MSG_ID_PARAM_VALUE:{UART_1_PutString("Param value ");UART_1_PutCRLF(0X0D);}default:break;}}}packet_drops += status.packet_rx_drop_count;}while debugging, the if(mavlink_parse_char()) is always false and is not going to switch case part. Can anyone tell whats wrong in my code & what does mavlink_parse_char() returns.

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GoldEyes November 4, 2013 at 5:39am

Hello,

It seems that I'm faced with the same problems like Priya.

The function call mavlink_parse_char() never Returns true.

If i try add some debug Information to the code (see the attached file) i get following results:

.........

0 139 0
0 127 0
0 127 0
0 152 0
0 127 0
0 156 0
0 127 0
0 153 0
0 127 0
0 141 0
0 127 0
0 142 0
0 127 0
0 127 0
0 148 0
0 127 0
0 153 0

.........

This tell me, that i receive Messages of the length 127-156 Bytes.

So why mavlink_parse_char() return false?

Can anyone help me??

mavlink_test.ino
Priya October 8, 2013 at 1:50am

hi, now i am able to receive and decode the packet from GCS. In hyperterminal its printing "heart beat" and "parameter request" according to the packets received. But now i am trying to send mission_count packet on detection of Mission_request_list.

void comm_recv()
{
uint8_t buf[MAVLINK_MAX_PACKET_LEN];
uint16_t len;
mavlink_status_t status;
mavlink_message_t msg;

p=UART_2_GetRxBufferSize();

if(UART_2_GetRxBufferSize()>0)
{

charc= UART_2_GetChar();

if((mavlink_parse_char(MAVLINK_COMM_0, charc, &msg, &status)))
{
if(msg.msgid==0x00)
{
UART_1_PutString("Heart Beat ");

}
if(msg.msgid==MAVLINK_MSG_ID_PARAM_VALUE)
{
UART_1_PutString("Param Value ");
}

if(msg.msgid==MAVLINK_MSG_ID_MISSION_ACK)
{
UART_1_PutString("Mission Ack ");
}
if(msg.msgid==0xA6)
{
UART_1_PutString("Radio ");
}
if(msg.msgid==21)
{
UART_1_PutString("Para_Req_list ");
}

if(msg.msgid==43)
{
UART_1_PutString("Mission_Req_list ");
mavlink_mission_request_list_t packet;
mavlink_msg_mission_request_list_decode(&msg, &packet);

mavlink_msg_mission_count_pack(1, 200, &msg,1, 200, 3);
len = mavlink_msg_to_send_buffer(buf, &msg);
UART_2_PutArray(buf, len);

}

if(msg.msgid==43)
{
UART_1_PutString("Mission_Req ");

}

}

}

packet_drops += status.packet_rx_drop_count;

}

But the mission_count packet is not being send. what is the problem??
Priya October 7, 2013 at 1:42am

q=0; q less than p; q++
Priya October 7, 2013 at 1:41am

oops , the code i pasted here is broken while pasting. My actual for loop is.
for(q=0;q
Priya October 7, 2013 at 1:36am

Thanks but I couldnt find that option in mission planner. But when i am reading the telemetry link i am continuously getting radio message( #0xA6. I am not doing mavlink connection to mission planner for the time being). So using the mavlink_parse_char() atleast i should be able to decode that packet right?? status->msg_received is always zero.
mP1 October 7, 2013 at 12:48am

I think i saw a checkbox in mission planner called debug mavlink messages. Might want to try.

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Mavlink Decoding

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