USB PIC projects

[you_were_lucky]

MP3 Player on PIC USB

nope ! not a good idea, you will only get a data rate of 800 Bytes/ Sec over one of these devices.

And you are trying to talk to a memory stick, which is a USB peripheral.

USB is not designed to talk peer to peer unless it is the new OTG standard.

you might do better to look at i-stick usb sticks as they will implement MMC interface in the future (and they are very small !)

be lucky

 

[TKS]

WHY not simple..!!

Don't know exactly the needing of you project but wy not buy a usb 2 serial converter..??

i use 1 on my laptop (ACER TM 435LCI)

ok maybe the savind of the $ each time..

i only can tell you that the usb thing needs softwaredrivers. (like the serial port also does, soow maybe to difficult????)

(the usb port could supply you the power needed for programming i think..)

TKS

 

[NaLiXiS]

Re: MP3 Player on PIC USB

nope ! not a good idea, you will only get a data rate of 800 Bytes/ Sec over one of these devices.

Why is that ??

How come it's so complicated to read on a usb device...??

And I did find some information for developping a driver for the usb flash drive...

Do you really think it's too complicated ??!!


Thanks again for your help on this..

 

[Nigel Goodwin]

Re: MP3 Player on PIC USB

How come it's so complicated to read on a usb device...??

Try asking MicroSoft!.

And I did find some information for developping a driver for the usb flash drive...

Do you really think it's too complicated ??!!

USB looks to be very complicated, if you check the MicroChip website you can download an application sheet for the 16C745, which explains what you need to do (both for PC and PIC). They also have a more recent design for a USB PIC programmer, the PICKit1, this also comes with all source code and is probably a good project to study to help understand USB.

 

[Chris P]

PIC to USB flash storage ???

Help,

I need to save data from a PIC onto a USB FLASH disk (one of those key-fob style ones) All the information I have found on PIC USB interface is for using the PIC as a slave device (ie. connecting it to a PC). I need to use it as a host.

Has anyone done this? how complex would it be for a newish PIC user?
I would appreciate any help as I'm striuggling to find anything on this topic.

Would there be an easier way? Basically I need to transfer around 16MB of data from the PIC onto a PC, without taking the PIC to the PC and preferable without the need of an additional program running on the PC.

Cheers Guys / Girls?

Chris

This seems VERY similar to what you need to do NaLiXiS, except I need to write not read. Still keep me up to date with any discoveries you make and i will do the same...

 

[libor]

Chris,
I was also thinking of a similar project: logging data with a PIC onto a widely available inexpensive removable media. I found some solutions that use CF cards, and also some information how to read/write an SD memory card. You should also consider using these memory cards, if you need more info on these, I can show you the links I found on this subject.

Re: PIC as a USB host (I have only read that it is too much for such a microcontroller)
I have no detailed knowledge of the USB protocol yet, but what I have read about it so far showed me, that the most difficult task of a USB host is the traffic management of the many slaves on the same bus, the device detection, enumeration, error handling, and also the many things a host computer needs to do to handle the many different drivers, etc. I have a strong feeling that if we focus on implementing a USB host that would be interfaced (hard coded) to one particular USB client only, with no other slave units on the bus we could avoid many of these difficult tasks. Using hard-coded set-up and other protocol related USB packet sequences we would need to write intelligent code only for the actual data transfers.
I have ordered a USB analyzer for learning. I am going to use it to record the traffic between a PC and a USB pen drive. I do not know yet how difficult this project would be, but I think it is worth trying it. This solution would certainly not get the USB certification , but for our needs this would be enough.

 

[Chris P]

Yes, I too have come to the same solution. Compact flash seems a lot easier to interface with. I have found all the pin outs for the flash cards and have begun wiring it up. Bloddy tiny pins though!!! Im using a 64MB flash card. Am i correct in thinking that this would use a FAT16 file system? How much extra do i need to do so the info can be recognised by a PC? Filenames spanning clusters etc? Help on this would be great if u have any. Cheers for the post though.

Here are some sights i have found helpful so far...
http://barrymichels.com/ide/
**broken link removed**
http://www.mcselec.com/an_127.htm

Cheers again
Chris

 

[libor]

Yes, these are the same sites I would suggest. Some more, you could also find useful:
A Circuit Cellar article about interfacing a PIC to CF card: https://www.electro-tech-online.com/custompdfs/2004/03/compactflashOnPicArticle.pdf
You can find here an mp3 player using CF Card with source code for PIC: **broken link removed**
A source CF adapters/converters (if you dont want to solder them): http://www.pcengines.ch/cflash.htm
And finally a last resort you might want to buy a CF Development Kit or only learn from: **broken link removed**

Re: file system
You are right, a 64Mb CF has FAT16 on it. FAT32 would be needed above 2Gb only, (there is also a FAT12 system that was used on floppy disks, it can be used below 8Mb only, maybe some lower capacity CF cards can be formatted to FAT12) We are lucky: no NTFS on CF cards.

 

[TheAnimus]

Has anyone ever tried making a device that gets seen as a compact flash card?

I was thinking about doing that as an interface into an IPAQ (Palm style hand held).