Hi again

The stepper driver ic L298n with L297 controller ic.

When upload if maps to pic method is as follows.
1 send numeric value 1 to select case 1 load map data
2 pc waits to receive "R" (pic ready)
3 send first packet "AxxxxBxxxx" A= address B= data
4 write data to eeprom or code space depending if A value < 128
5 send "s" to PC
6 wait for next packet
7 if "A9999" received end of data transfer

Sometimes upload is fine.
There is 13 blocks of 256 words that make up the map data and when I view the pic memory I can see areas with rows of zeros and some 00001 and 00002 where a value of 55 should be. this fail area is for 4 memory rows and then comes good. When upload of map is in progress the stepper driver is set to disable and .12 amp of draw only from power supply in this state so noise at this time is unlikely.


see picture taken from meProg The row with 11111 is a partition only and npt read. Below that the values should be progressively larger than the 45 values that are correct.

Beginning to suspect the usb to serial adapter. This is difficult to see because if the data string is not AxxxxBxxxx then error occures. so the error is only in the values after B as the correct addresses are written . It is as if the charge pump runs out in the pic and then recovers. Also the defective area is mainly in a similar area. Tricky hey


Name: P1000343.JPG Views: 433 Size: 166.0 KB



Code:


'-------------Main Code------------
DEFINE HSER_RCSTA 90h 
DEFINE HSER_TXSTA 24h 
DEFINE HSER_BAUD 76800
DEFINE HSER_EVEN 1 
DEFINE OSC 20


INTCON2.7=0    ' Enable PORTB pull-ups 18f458


TRISB = 110000
PORTB = 000001


loadlamp1 var word
loadlamp2 var word
mapflag var byte
data1 VAR word
location VAR word
computercontrol var byte
computerpos VAR word
connect var byte


'------------------------------------------------------------------------------------------------------
mainloop:


if RCSTA.1 then  ' Overrun error? used to reset input ready to recieve
    RCSTA.4=0     ' clear it
    RCSTA.4=1
    endif


if PIR1.5 then gosub loaddata    'if a chaeacter has arived at serial in the  PIR1.5 will = 1


goto mainloop:


'------------------------------------------------------------------------------------------------
Loaddata:
 
hserin [dec1 data1] 'read case number from pc 1 = load 2 = computer control  4 = connection extablished 5 = disconnect
select case   data1


case 1
loadlamp1 = 0
loadlamp2 = 6
HSEROUT ["R"]  'pic ready to recieve


Load2:
HSERIN 5000,TimeOut2,[WAIT("A"),hex4 location,WAIT("B"),hex4 data1] 'if next packet not recieved in 5 sec then go timeout 2


loadlamp1 = loadlamp1 + 1          'led flash while data transfer in progress
if loadlamp1 > loadlamp2 then PORTB=PORTB << 1
if loadlamp1 > loadlamp2 then loadlamp2 = loadlamp1 + 6
IF PORTB.3 THEN PORTB = 000001
  
if location = 9999 then goto TimeOut2  'when A9999B0000 sent from pc data transfer finished
if location > 128 then goto cs 'codespace addresses are always greater than 128    
write location , data1.lowbyte
write location+128 , data1.highbyte       
HSEROUT ["S"] 'please send next data packet
GOTO Load2:
      
cs: 
Writecode location ,data1
HSEROUT ["S"]  'please send next data packet
GOTO Load2


TimeOut2:
if location = 9999 then 
HSEROUT ["Recieve ok"]
else
HSEROUT ["F"] 'fail load set to pc
endif
HSERIN 20,TimeOut3,[WAIT("recieve nill")] 'this is needed to final clear PIR1.5 and stops main loop jump to loaddata
TimeOut3:
PORTB = 000001
RETURN


case 2
HSEROUT ["R"]
computercontrol=1
HSERIN 5000,TimeOut2,[WAIT("P"),dec3 computerpos]
location = 9999
goto TimeOut2


case 3
HSEROUT ["R"]
computercontrol=0
location = 9999
goto TimeOut2


case 4
HSEROUT ["C"]
connect=1
location = 9999
goto TimeOut2


case 5
HSEROUT ["D"]
connect=0
location = 9999
goto TimeOut2
end select
return




end