Why use a bootloader?

[HenrikOlsson]

Hello,
Yes, when you press Program there should pop up two messages/windows, first one with a progress bar that says Programming and then, when it can't reset the PIC, a second one saying Please reset target microcontroller in order to access the bootloader process... When you reset the PIC the second window will close and you can monitor the progress in the first window, it only takes a couple of seconds depending on the size of the program.

Have you verified that the serial communication is working, ie by using HSEROUT/HSERIN to send and receive data. Perhaps you've mixed up the RX/TX lines?

/Henrik.

[F1CHF]

Same player shout again
I am still in the same marmelade !
I have checked the hardware RX TX max232 seems good (no mix)
I will try to test as you said (transmit between PIC and laptop)
I suspect also that my programmer is not wonderfull
I must program sometimes 5 times to avoid errors
I must compare iniatial file from MCloader (16F874_20.hex) with the data burned in the pic !
I have tried with two differents PIC

for this week I will be out for 3 days, so, hold the line !
I lost already 3 days on this crazy thing, no problem because I am retired ! hi ...
Francois

[F1CHF]

Still me, with the same problem
I spent one day without success !
abstract : I got garbage using Hserout (to test my RS232 line for bootloader function)
see my terminal V1.9 log file (hexa dump and ascii dump)
question :
What is wrong in my design ?
I have tested in XT and HS clock mode
I have changed the MAX232
LCD and Blink led seems normal (pic is alive !)
I am lost !
Thnaks in advance
Francois

the program test is the following :
' Using PIC 16F874 @ 20MHZ
'
DEFINE OSC 20
' Set LCD Data port
DEFINE LCD_DREG PORTD
' Set starting Data bit (0 or 4) if 4-bit bus
DEFINE LCD_DBIT 4
' Set LCD Register Select port
DEFINE LCD_RSREG PORTD
' Set LCD Register Select bit
DEFINE LCD_RSBIT 2
' Set LCD Enable port
DEFINE LCD_EREG PORTD
' Set LCD Enable bit
DEFINE LCD_EBIT 3
' Set LCD bus size (4 or 8 bits)
DEFINE LCD_BITS 4
' Set number of lines on LCD
DEFINE LCD_LINES 2

' Hardware configuration
' ======================
TRISC = %10000000 ' PORTC.7 is the RX input
' PORTC.6 is the TX output

' Serial communication definition
' ===============================
' Using internal USART and MAX232 to interface to PC

DEFINE HSER_RCSTA 90h ' enable serial port, enable continuous receive
DEFINE HSER_TXSTA 20h ' enable transmit, BRGH=1
DEFINE HSER_SPBRG 129 ' 2400 Baud @ 20MHz, 0,17%
DEFINE HSER_CLROERR 1 ' Clear overflow automatically

Pause 500

start:
high portd.1
pause 100
low portd.1

lcdout $FE ,1,"test"
pause 500
lcdout $FE ,1, "to see"
pause 500


hserout ["test TEST"]
pause 1000
goto start

[F1CHF]

Stop it works !
Now I have the solution to lost one week !
use a bad Xtal/quartz !
Pic was running at 6 khz ! instead of 20 Mhz

just one thing ... put HS (high speed) at the config time(first load) for the bootloader
second think ... close your terminal program to avoid conflict during MCloader time !

Thanks for helping me ..
Francois