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aack...I canny git the18F26K22 to boot its wee load [solved]
#3
Hi Mikael:

Thanks for the reply. I looked at that thread and fixed the problem!

Some comments on the thread:

- I can't use USART2, as the circuit board is fixed with USART1, so I never bothered to test the second port.

- It seems difficult to believe that a small error in the bit times would cause it to not work at all. Intermittently perhaps. Trying lower baud rates would help that issue, but I never bothered.

- The errata tidbit about setting BRGH = 1 and BRG16 = 1 only applies to rev 2 chips. Since my 26K22 chips are rev 4 (as reported by pickit-3 when it connects), I never bothered with this.

- Posts by hobbytronics and ghu show extra assembly code for the user_code section. As I have not programmed pic assembly since the early 90s (I use CCS C), I had to dig into assembly a bit (pardon the pun).


IT NOW RUNS DUE TO TWO THINGS I DID:

1) GOT RID OF MPLAB-X -- this never could talk to the Pickit-3. I find it reprehensible that Microchip allowed this software out without testing it. I am apparently not the only one who ran into problems with it. Maybe there is a firmware update for pickit-3 to fix it, but now that I have my bootloader built, I won't need mplab except to program a chip, or maybe build ds30loader for another chip in the future. I loaded the MPLAB version 8.70 that came on disk with the pickit-3 and it works great.

2) ADDED A FEW ASSEMBLY LINES TO USER_CODE:

UserInit macro

; tweak: Make uart-1 pins digital:
movlb 0x0F ; MANDATORY: BSR set to SFR bank
movlw b'00000000'
movwf ANSELC ; MANDATORY: analog off on port C
movlw b'00000000'
movwf ADCON0 ; not necessary, but adc off
movlw b'10111111'
movwf TRISC ; not necessary, but tx pin RC6 as output

A big thanks to hobbytronics and ghu for finding this!

gil smith

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RE: aack...I canny git the18F26K22 to boot it's wee load, and me head's aboot tae explode - by teletype-guy - 2012-06-23, 20:44:59

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