On 10 Dec 2008, at 22:26 , Joep Suijs wrote: > > 2008/12/10, Sebastien LELONG <[email protected]>: > >> My questions are: >> >> * do you know any standard protocol/way of talking to a PIC <=> PC ? > There are a lot. Wbus is one of them, used to communicate the wisp > programmer. Mine is close to the wisp programmer: the PC program is an extension of wisp.py
>> >> * how do you deal with that ? (do you deal with that ?) > Currently, I don't. I do. > But I'v dealt with a lot of serial protocols in the past and would > suggest you choose a protocol with the following features: > - independent framing - you should be able to parse the frame without > understanding the content. check > - checksum as part of the frame. check > - have a command byte (or frame type) field at a pre-defined place. check > - allow full 8-bit transfer of data. This means you have to do > something special to transfer the framing char - an escape char is the > most easy to implement. check > On top of this you could: > - add a data lenght field in the frame. frame is fixed length of four bytes > - add an address field in the frame. check This address field could enable PIC-to-PIC communication: I did not enable that. On top of this: my protocol works with a bootloader too. So you can actuallly reprogram a node from the PC. Yes, you can enumerate as well. You can also program all nodes at once. Also, the bus wire (6-wire telephone cable) can be reversed without damage and the connectors and crimp device can be bought in the supermarket. The bus does power too. I can port the project to JALV2, but this will take time. The blog has to be up and running before I do it, since there is a massive amount of documentation, photos, schematics, hardware, pyhon libraries and applications. There is also a C API for on the PC. You will need special hardware as well, for instance a PIC16F628 driven translator between bus signals an serial data. I made an SMD USB translator board as well, but I can't remember if I got it working. Seb, you could help me a lot to get this on the web and into jallib. I can ship you some working hardware so you can help developing and documenting. --- ir EE van Andel [email protected] http://www.fiwihex.nl Fiwihex B.V. Wierdensestraat 74, NL7604BK Almelo, Netherlands tel+31-546-491106 fax+31-546-491107 --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "jallib" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/jallib?hl=en -~----------~----~----~----~------~----~------~--~---
