topic Re: KL46 UART receive data handling problem with WiFi module in Kinetis Microcontrollers

KL46 UART receive data handling problem with WiFi module

yasararafathcs — Thu, 19 Jun 2014 19:11:00 GMT

Hi all,

I am using KL46 UART2 to communicate with the WiFi module. Data is able to transmit from the KL46 to WiFi and WiFi to the remote server.

The other way communication i.e.)receiving by the KL46 from the WiFi module is not through. Here at starting I configured with 115200bps baud rate. By that time I am able to receive only the single character randomly from the sent data by the server.

Later I reduced down up to 1200bps. At this point I am able to receive the data but it is in a shuffled manner. For example the characters in the middle coming first and some strange character at the end of the data.

I am using Interrupt Service Routine to receive the data through UART. Anyone facing the same problem. Please help me out.

Thanking you,

Re: KL46 UART receive data handling problem with WiFi module

perlam_i_au — Thu, 19 Jun 2014 20:34:31 GMT

Hello Yasar:

In this case I would like to take a look to your code just in order to check configurations, could you please share it?

Have a great day,
Perla Moncada

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Re: KL46 UART receive data handling problem with WiFi module

yasararafathcs — Fri, 20 Jun 2014 05:20:37 GMT

Hi Andrea,

This is the ISR code I am using

void __irq_interrupt__ wifi_uart_isr(void)

{

ui = UART_S1_REG(channel);

if (ui & UART_S1_RDRF_MASK) {

simSerialBuffer[indxIn1] = UART_D_REG(channel);

i = (indxIn+1) % WIFI_UART_BUF_SIZE; // WIFI_UART_BUF_SIZE = 1024

if (i != indxOut) indxIn = i;

else bufOvrn = 1;

}

Re: KL46 UART receive data handling problem with WiFi module

bobpaddock — Fri, 20 Jun 2014 11:58:37 GMT

post.user_wrote.label:

if (ui & UART_S1_RDRF_MASK) {

simSerialBuffer[indxIn1] = UART_D_REG(channel);

i = (indxIn+1) % WIFI_UART_BUF_SIZE;

There are two different variables there indexIn*1* and indxIn.

Is that your intention? More appropriate names would be beneficial.

Are the index variables properly declared as volatile?

Does any action need to be taken to clear the status register on that part?

Re: KL46 UART receive data handling problem with WiFi module

bobpaddock — Fri, 20 Jun 2014 11:59:49 GMT

Something I wrote a while ago about common Queue problems:

Software Safety: Even "Design Patterns" still have bugs. A common Queue bug.

Re: KL46 UART receive data handling problem with WiFi module

yasararafathcs — Fri, 20 Jun 2014 13:39:22 GMT

Hi Bob,

Everywhere it is "indxIn" only. I have taken care of clearing the status register.

I am going through the blog you referred.

Thanking you.

Re: KL46 UART receive data handling problem with WiFi module

perlam_i_au — Fri, 20 Jun 2014 16:53:59 GMT

Hello Yasar:

I mean initialization configuration for UART module. could you share it?