Like a ring buffer.
#Picaxe 20X2
#no_table
Setfreq M64 '// Wide open for faster processing.
Hsersetup B115200_64, %001
setintflags %00100000,%00100000 '// interrupt on hserial receive
MAIN:
do
'// waiting for hser background data
loop
Interrupt:
do while ptr <> hserptr '// Ring buffer
sertxd (@ptrinc," ") '// Process byte & increment ptr
loop ' // until ptr = hserptr
flags = 0 ' // Clear the hserint flag
setintflags %00100000,%00100000 ' // re enable interrupt on serial receive
return '// Back to mainIf using a 28X2, why do you need to move the bytes to user ram? The data can be sent directly from the scratchpad.
I am trying to understand what you are asking here but it doesn't make sense. You can't dump 128 bytes into a single location.
As that is available, it'd be daft not to verify the CRC on rxd data
I used a CRC16 checksum for the HABAXE project.
The main problem is making it work. That requires an understanding of MMC/SD/SDHC card hardware and protocols, having the skills to do it plus the time to design, debug, test, and make it work robustly.
'// **********************************************************
'// * Data Logger Using Hser & User Ram & Scratchpad *
'// * to store 208 bytes received from ECU *
'// ***********************************************************
#picaxe 20X2
#no_table
#terminal 38400
setfreq M32
pause 2000 '// Stabilize
symbol cntr = b4 'counter for loop timer
symbol error_flag = b5
sertxd ("Starting",cr,lf) '// for debugging only
pause 16000 '// for debugging only remove in final code
hsersetup B115200_64, %001
setfreq m64
hserptr = 48 '// preload herial pointer
ptr = 48 '// preload SP location pointer
bptr = 48 '// preload User ram pointer
'// these will overflow to zero after 80 bytes
error_flag = 0 '// just in case
MAIN:
Do
Gosub request_data
pause 16000 '// every 2 seconds @ 64 Mhz
Loop
Request_data:
error_flag = 1 '// data requested
setintflags %00100000,%00100000
cntr = 0
hserout 0,("A") '// Send "A" to tell the ECU to send data packet
'// Wait for interrupt on hser receive
'// If no interrupt after 20 counts then
'// ECU did not respond.
do
inc cntr : pause 1
if cntr >= 20 then
error_flag = 3
endif
if error_flag = 3 then gosub error_message
if error_flag = 2 then gosub process_data
if error_flag = 0 then exit
loop
return '// to main loop
Process_Data:
'//do whatever you want here with data now captured
'// in User Ram and SP Ram.
'access User ram with "peek" or "bptr / @bptr
'access SP ram with "get" or "ptr" / @ptr
setfreq m32 '// so we can use the terminal at 38400
'// User RAM (bptr)
for bptr = 48 to 127 ;Get 80 bytes from user ram starting at loc 48
sertxd ("BPTR ",#bptr," = ", #@bptr,cr,lf) ;display the bytes
next
'// Scratchpad (PTR)
for ptr = 0 to 127 '// Get 128 bytes from scratchpad memory
sertxd ("PTR ",#ptr," = ",#@ptr,cr,lf) '// Display the bytes
next
setfreq m64 'back to 64 MHz for fast processing
'// reset pointers for next packet
hserptr = 48
ptr = 48
bptr = 48
error_flag = 0 '// Data was processed all clear
return '// returns to main
Interrupt:
'// -------------------------------------------------------
'// Let a few bytes arrive before processing so we don't
'// get ahead of the incoming data.
pause 4
'// store the first 80 bytes in user ram 44 - 127
do until ptr = 0
@bptrinc = @ptrinc
loop
'// The next 128 bytes go into the scratchpad
pause 200 '// > 15ms @ 64Mhz make sure all bytes received
flags = 0 '// clear interrupt flag
setintflags %00100000,%00100000 '// enable the interruot
setfreq m64
error_flag = 2 '// Data received
cntr = 0 '//clear the counter
return '// returns to request data
'// -------------------------------------------------------
Error_Message:
'// --------------------------------------
setfreq m32
sertxd ("No Response From ECU",cr,lf)
setfreq m64
error_flag = 0 '// clear the flag
return
'// --------------------------------------'===================================
#Picaxe 08M2
#No_Data
Setfreq M32
Pause 100
'=====================================
high C.0
pause 1000
hsersetup B115200_32, %000
MAIN:
w1 = $FFFF ; set up a non-valid value
do
hserin w1 ; receive 1 byte into w1
if w1 <> $FFFF then
If w1 = "A" then
w1 = $FFFF
gosub send_data
endif
endif
pause 10
loop
Send_data:
'------------------------------------------------------------------
'// This is 208 bytes
hserout 0, (255,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20, _
21,22,23,24,25,26,27,28,29,30,32,32,33,34,35,36,37,38,39,40, _
41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60, _
61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80, _
81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100, _
101,102,103,104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120, _
121,122,123,124,125,126,127,128,129,130,131,132,133,134,135,136,137,138,139,140, _
141,142,143,144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,160, _
161,162,163,164,165,166,167,168,169,170,171,172,173,174,175,176,177,178,179,180, _
181,182,183,184,185,186,187,188,189,190,191,192,193,194,195,196,197,198,199,200, _
201,202,203,204,205,206,255)
pause 500
goto main