Converting HSERIN Data to Number

[HenrikOlsson]

Hi,
The UART RX interrupt always* fires for each byte that comes into the RX buffer, there's no way to set a "threshold" on when the interrupt fires. After all, the buffer is only two bytes deep. But yes, you could set your code up so that after proper sync, adress, command etc you grab one byte and that's it.

* Well not always but that's details details details.....

/Henrik.

[RossWaddell]

Hi,
The UART RX interrupt always* fires for each byte that comes into the RX buffer, there's no way to set a "threshold" on when the interrupt fires. After all, the buffer is only two bytes deep. But yes, you could set your code up so that after proper sync, adress, command etc you grab one byte and that's it.

* Well not always but that's details details details.....

/Henrik.

Thanks again, Henrik. Much appreciated. I'm going to try all this out tonight.

[Art]

serialbuffer byte [4]
serialbyte var byte
index var byte

…

‘ ooh looky here… a serial byte arrived
for index = 1 to 3
serialbuffer[index] = serialbuffer[index-1]
next index
serialbuffer[0] = serialbyte

Now instead of checking for the first byte in the serial string,
check for what you call the termination byte.
I don’t know what that is, so now it’s $FE.

if serialbuffer[0] = $FE then
‘ we know the bytes serialbuffer [0,1,2,3] are the desired 4 byte string in reverse
‘ unless only a partial command was received
if serialbuffer[3] = “S” then
‘ we know now that the entire four byte command was received if there was no serial error
endif
endif

[Art]

Now if you only wanted to grab say byte 2 (beginning counting from zero).

counter var byte
counter = 0

'oh looky here.. a serial byte arrived

if serialbyte = “S” then
counter = 0
else
counter = counter + 1
endif

if counter = 2 then
byteyoucareabout = serialbyte
endif

A lot of this will fall apart if another byte of the command can be the same value as the “S” or the termination character,
which is why it’s better to go something close to the first way, and check both start and end chars if they are always the same.