UART5 input on TM4C123 using a Spectrum Satellite Receiver

Hello Alexander,

The configuration seems fine, but the last loop should be

int i=0;

while (1)
{

if(UARTCharsAvail(UART5_BASE))

{
  buffer[i++] = UARTCharGetNonBlocking(UART5_BASE);

}
}

Regards

Amit

Hey Amit,

Thank you for the answer.

I got a reading in to the buffer, though it seems like getting the entire data being sent from my receiver might be harder. As I described above, the goal is to have a continuously loop receiving data from the UART and storing it / updating the buffer. After storing it to the buffer I can later extract what ever numbers i want.

Can I still read the entire hex number being sent to the UART when using the UARTCharGet function?
If not, what are my options?

Hello Alexander

If you mean 16-bit word, then no, it cannot be done by the CPU as the UART Write and Read entry points are 8-bits. The UART module does not concat or split data. So basically you would need to do that in Software,

Regards

Amit

Hi Amit,

The Spectrum Receiver sends 16 bytes of information. If you look at the picture I pasted in my first post, it shows the setup. So there is no way my Tiva can read this data? Changing the Spectrum Receiver software is not possible.

Hi Amit,

Well that is great news :)

Can you help me put up the UART FIFO so that the data will stream freely and keep updated? Put me on the correct track?

When using the code above, my buffer refreshes adding two characters "d". All other characters in the buffer remain ","

Hello Alexander,

The FIFO is enabled by default when UARTConfigSetExpClk is called. Is the device transmitting the same characters to TIVA or is it transmitting the ASCII code for each of the characters?

Can you check the physical RX pin on a scope and check for one line what characters are being sent to TIVA?

Regards

Amit

Hi Amit,

I don't have a scope, but I reconnected my Receiver to a UART-USB adapter and started RealTerm.
When displaying the data as ASCII, I clearly see it sending ASCII code for each character (red in the table bellow).

Here you see a screenshot from RealTerm:

Hello Alexander,

Can you check the memory address of the buffer and send across a snapshot of the same?

Regards

Amit

Here is a screenshot from CCS when in run and live:

Hello Alexander

The memory browser and not the expression browser. Type the address of buffer in the memory browser

Regards

Amit

I added a small piece of code allowing the while(1) loop update the buffer continuously:

Here is a two screenshot from the memory browser:

When operating my transmitter the 8-bit Hex window updates freely and exactly as i wish, though when using the Character window, very small changes are made, practically impossible to extract any data.

Is it possible for me to use the 8-bit Hex window style, and draw that data out and store it separately?

Hi Amit,

You last post helped tons! Thank you very much!
The final part of my code ended up like this:

int i = 0;
while (1)
{
if (UARTCharsAvail(UART5_BASE))
{
buffer[i++] = UARTCharGet(UART5_BASE);
if (i == 16)
i = 0;
}

thro = buffer[3] + (255 * buffer[2]) - 154;
int x1 = buffer[8] - 14;
yaw = buffer[9] + (255 * x1) + 357;
int x2 = buffer[6] - 10;
pitch = buffer[7] + (255 * x2) + 358;
int x3 = buffer[4] - 6;
roll = buffer[5] + (255 * x3) + 357;
}

The bottom scaling part allows me to store each of the four numbers separately.