[SOLVED] 18F4550 bootloader problem

[varunme]

18F4550 when programmed with microchip bootloader firmware and used with
**broken link removed**
board , when connected to USB , message shows , usb device not recognized and shows unknown device in device manager , I am using K182 programmer from Kitsrus for programming the PIC , I didn't changed anything including fuse settings from the original bootloader , what can be the reason for not functioning ?

 

[pmar_kpj]

hi,
Try to check if the oscillator is on!
Measured on pins 13 and 14 and see if you have approximately 2V.
If you have not: change the 2 capacitor or the quartz.
Measured on pin 1 and see if you have 5V.

 

[varunme]

pin 13 is giving 0.98V and pin 14 is giving 2.14V and pin 1 is giving 1.64 V

 

[pmar_kpj]

Hi!

The voltage on pin 13 is not good ! change or verify c3 !

remove C15 and verify R1 ! On C1 you have 5 V ? On pin 1 you need to have 5V.

 

[devil6600]

hi all,

varunme did you got it working? if yes, can you please let me also how you solved it.

members i am also having a similar kind on issue, if you wish please take a look at my issue also (https://www.edaboard.com/threads/224034/)

thanks

 

[varunme]

Not yet , devil6600 , i will definetly inform you dear once i rectify it :smile:

 

[abidr]

if you are using the same schematics as the one mentioned (olimex circuit), then I think you need to keep RB4 button pressed or short to ground while connecting the board to the USB port of PC. You need to burn the bootloader with a hardware programmer, later your could flash the chip with PDFUSB from microchip.

 

[varunme]

RB4 shorted at connection time and inconjunction with reset switch also tried

 

[abidr]

There are only few possibilities here:

1) USB D+/D- have been connected in reverse.

2) correct PIC driver has not been installed on PC

3) long shot boot loader has not been installed properly.

my hunch is no 1.

 

[varunme]

I cannot install the driver as i connect the board , message says unknown device

 

[abidr]

Confirm the following from my previous post:

1) USB D+/D- have been connected in reverse.

 

[varunme]

Hi!

The voltage on pin 13 is not good ! change or verify c3 !

remove C15 and verify R1 ! On C1 you have 5 V ? On pin 1 you need to have 5V.

C1 is giving 4.54V

---------- Post added at 09:32 ---------- Previous post was at 09:21 ----------

D+ and D- are fine

---------- Post added at 10:01 ---------- Previous post was at 09:32 ----------

the MCLR (pin1) now shows 5V (it was a mistake by me that the power adapter wasnt connected , now connected it and shows 5V in MCLR)
C3 changed , but the pin 13 , shows only 0.80V

 

[varunme]

in circuit C1 and R1 are fine, should i remove and check ?
thanks

 

[bigdogguru]

Hi varunme,

What is the exact bootloader you are using? Can you provide a link to it on the Microchip Website?

BigDog

 

[varunme]

I tried almost all Bootloaders and the USB firmware without bootloader as well
from Microchip
**broken link removed**

thanks
varnme

 

[pmar_kpj]

Hi!

try to burn this : **broken link removed** ! if led blinking is good!

 

[varunme]

I have tried this and programs created by me to check each ports , all are working except the firmwares using USB

 

[devil6600]

what is the value of capacitor you are using at vusb pin?

try the attached hex file, it should blink led on porta.0 (pin2) 5 times a second, this will confirm pic is running at proper speed.

 

[varunme]

c5 marked as 0.1 and is disc capacitor , the code (attached) works correct

 

[pmar_kpj]

hi !
i attach a CCD Demo from MCHPFSUSB v2.2 USB Framework compiled and tested on mai board with 18f4550.
Please burn a "USB Device - CDC - Basic Demo - C18 - PICDEM FSUSB.hex"!