In-Circuit Programming Via USB

[sdelima]

Hey everyone,

How is it going? Has anybody ever written a program to program a Microcontroller (that has a built in USB port) via its USB port.

If anyone has any ideas please let me know

Thanks a ton

Shane

 

[Chancy99]

Which micro has a built-in USB port ?

The easiest way is to use a bootloader. Either with hardware support like some of the Atmel MegaAVR chips, or do it yourself. The reset vector code checks an input mechanism (serial port, USB, SPI, whatever) for a special condition. If it sees it ('$' char on serial) it then goes into receive mode to download the new code, and writes it into place.

Search on bootloader and your micro name. Or check

http://www.avrfreaks.net

for Atmel AVR info.

If USB isn't really "built-in" to the chip, you can use something like FTDI's usb chips, then you have a couple of options. The 232 pretends to be a serial port, so your normal serial code can talk to it. The 245 uses a parallel interface - 8 bits.

Would need a few details more ...

Dean.

 

[xray]

sdelima:

It is a big project for an MCU that does not have a dedicated USB communication. I have started a similiar project with a MC68HC908JK3/JL3; However, I am aiming at getting the USB port to enumerate the MCU. I am utilizing a MAX3340E USB translator to communicate between the USB and SIE, serial interface engine. The SIE may end up being an fpga chip before data is ready to be read by the MCU. It is a big project, but interesting. My best information has come from the USB.org website. If I can give you any more specifics let me know. drollinger@montana.net

Cy Drollinger

 

[sdelima]

Hey Guys thanks for the replies

The microcontroller I am using is the MC68HC908JB8. it has
a a USB module which is designed to serve as a LS USB device. The MCU does not have a SCI (so I might have to implement a bit banging technique). If any one has any ideas as to where i can find some boot loader examples i would greatly appreciate it.

Thanks for your help

sdelima

 

[Chancy99]

Hmm, don't know about the MC68 series. But for Atmel AVR you can check out these - they should give you pointers :

costs $49

http://www.prllc.com/prllc_homemainAVRBL-8.htm

Design note - has actual code

http://www.avrfreaks.net/Tools/showtools.php?ToolID=328

Dean.