USB Bootloader for 18F2550/18F4550
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The goal of this web page is to describe :
- The installation of the Microchip HID bootloader,
- The bootloader test.
The PC software
The fist thing to do is to download the "Microchip Libraries for Applications (MLA)" and to install it on the PC. I use the v2017_03_06 release.
The PC program is in the "...mla\v2017_03_06\apps\usb\device\bootloaders\utilities\bin\win" folder.
If every thing is OK you can launch the "HIDBootLoader.exe" and obtain the control panel on the left (with "device not detected" because no PIC is already connected).
The PIC firmware
The second step is to program a PIC with the bootloader firmware. I have used the "USB Device - HID - HID Bootloader - C18 - PIC18F4550.hex", you will find compiled in the old Microchip distribution (Microchip MCHPSUSB v2.3.1).
You can also use the "mla\v2017_03_06\apps\usb\device\bootloaders\firmware\pic18_non_j" program which you must complile with MPLAB.X.
Note : the old PC program for the HID bootloader seems not compatible with the program compiled with XC8 and MPLAB.X. Take care to use the MLA distribution one.
Test board
I have used the USB interface board modified for a 18F4550 PIC, i.e. :
- 20 MHz quartz with adapted capacitors,
- USB pull-up removed,
- A switch on the RB4 pin.
The connection
Once connected, with RB4 of the PIC grounded during power on, Windows recognise an HID USB interface and "Device attached" should appear on the control panel of the Bootloader.
The test program
Select the hexa file to load, program the PIC and do a reset with RB4 to the +5V and the program should run.
You will find a test program in the "PIC 18F2550/18F4550 Test programs" for instance "test05".
The program is running !
This program is a binary counter on the RB0,... RB3 leds.
It's written using XC8 under MPLAB.X.
You just have to write your program from the 0x1000 address, the 0x0000 to 0x0FFF space being reserved for the bootloader.
PIC 18F2550
For the PIC18F2550, you use the same software on the PC and on the PIC than for the PIC18F4550.
On the left, the test on a Labdec breadboard.