AVR Freaks

Hi,

    In my application the host is sending the data. In  between the transfer  the host will check the device is connected or not by continuous pinging in background (receive data from host  and responds back) .

It is for host to check the connection status.

I tried to implement this with the help of solution suggested    Lajon  . But if host is s sending other data the device is getting disconnected "stopping transfer to check device connection status " .

Why it is happening? It is not possible to perform multiple transfers at a time?

hi  Lajon ,

    I used to send string to check the connection status every instant i send "1234". The device is connected  i have to send back the same  same string "1234" if the device is connected. It need to happened  at every instant. If host send the other data the connection breaks.

I'm receiving all data to the same buffer i set a flag and reading from main. How can i resolve this.

Thanks & Regards

Hi Lajon ,

    The normal messages i'm sending is all in  numbers ( string ) like numbers from  2000 to 3000 (i'm doing such a way that if i receive 2000 perform operation:1 if  receive 2001 perform:2). For pinging I'm doing in such way w that if i receive "1234" sending the same data back to the host.

Hi  Lajon,

 My application is to read the command  from the host to the device and perform the operation suggested by the host and send  acknowledgement back to the host from device.

  1.Device Waiting for second request from host for sending response for first request.

1st request ---->No acknowledgement received from device.

2nd request---->Host received  acknowledgement for 1st request .

3rd request----->Host received  acknowledgement 2nd request.

--->Why this issue is happening? How can i resolve this issue i'm stuck with this any help will be appreciated.

Thanks & Regards

Hi  Lajon ,

" I think you need to find out if the first ack is received eventually or if it in fact is not received "--->I checked the traffic using wire shark the ACK is receiving to the device.

   I tested this with the basic application code. Read data from the host and send the same data back to host. It is also giving the same issue. 

CODE SNIPPET:

void uart_rx_notify(uint8_t port)
{
UNUSED(port);
data_ready=true;
} 

-->Here when the data is received i'll send back the same data to the GUI.
-->Here i'm reading data from main.

while (true) {
if(data_ready)
{
udi_cdc_read_buf(rec_buffer,3);
udi_cdc_write_buf(rec_buffer,3);
} 

-->In this code i'm not making any changes i made changes only for this two functions

ISSUE:

In this same application also i'm facing the same issue. In the first case the GUI is sending 111 then 222. Here if i receive 111 i need to send back 111. In my case the device is sending 111 when 222 is received. Even the first response as the response for second data .

LOG:

byteArr55-->Data from host
received data ->Data send back from device.
 

libusb initialised
handle-->libusb device handle 0x7f263c173a60
device found

count----------------------------------------------------count-->1
byteArr55-->111

3-->bytes sent to device
read00
capacity-->64
------------------------------------ bytes read from device----->0
received data ->

byteArr55-->222

3-->bytes sent to device
read00
capacity-->64
------------------------------------ bytes read from device----->3
received data ->111

count----------------------------------------------------count-->2
byteArr55-->111

3-->bytes sent to device
read00
capacity-->64
------------------------------------ bytes read from device----->3
received data ->222 

Every time it is not sending the response for 1st data. It is sending it as the response for 2nd data.

Please have a look at this issue.

Thanks & Regards

hi  Lajon ,

 I faced this issue on my application now i'm checking this on the code i mentioned above there also i got the same error.(Recv and  Snd back the same data).

==> "Is the host waiting for the response before making a new request"

      --->Here i did in such a way that host is continuously sending 111 & 222 alternatively.   Host wont wait for any request i will send continuously in both cases.

==> Find out if the first ack would eventually be received if there is no other activity

--->No other data transfer is happening in between i checked traffic using the wireshark. 

---->Device not ready to respond instantly it wait for another data to come to  send response. If i debug i can see the data on the buffer which is using for send data it wait until next request from host.

Hi  Lajon ,

  I tried with sending data one time to host without the loop. When i click send then only host transfer the data.

First time the device will send back the data which is received. 

2nd data it wont send anything back. When the 3rd data is send by the host ,device will send response for the second data. How this happens?

Best Regards

hi  Lajon ,

I checked  the code you send with mu GUI it is giving the same error. I'M  unable to check with the python code.

I'm attaching the host code below please check this code and verify.

Thanks & Regards

Hi  Lajon ,

I added the delay as you suggested and checked it with delay of 100 and 1000.

for(int i=1;i<=1;i++)
			{

				System.out.println();
				System.out.println("count----------------------------------------------------count-->"+i);
				write2(handle,byteArr);
                                Thread.sleep(1000);
				read(handle);
				write2(handle,byteArr1);
                                Thread.sleep(1000);
				read(handle);}

=>First time host will send 111 & 222 respectively one time

•   Able to receive both data correctly.

=>2-Sending  111 & 222 respectively one time:

• First data -No response 
• 2nd data- 111 AS RESPONSE

=>3rd Sending  111 & 222 respectively one time:

• First data - 222 AS RESPONSE
• 2nd data- 111 AS RESPONSE

If i tried this i'm getting this response .

      ==>If i restarting the device before every receive this issue is not happening.

      ==>After receiving some data for the next sequence this issue is coming.

      ==>If i send this data in for loop ten times first 10 time data will receive and send back to the host correctly.

              After completing the loop 10 times , if i tried to send again in loop i=1(data-111 No response), i=2(data-222 resp -111) ,i=3(data-111 resp-222) like this happens.

I think you are more clear about the issue now. Please help me with this

Best Regards