Comments on: Bus Pirate: Binary I2C mode

By: Ian

Ian — Tue, 22 Jun 2010 13:31:50 +0000

1-wire has been implemented for some time.

By: tissit

tissit — Tue, 22 Jun 2010 13:29:34 +0000

So is 1-wire coming too?

By: Ian

Ian — Thu, 25 Feb 2010 06:51:09 +0000

You’ll need to tell it how many bytes to write with the write command: (0001000 + 2) 0×90 0×10. There’s some examples around that might help too: http://dangerousprototypes.com/category/binmode/

By: Vikram Kopuri

Vikram Kopuri — Wed, 24 Feb 2010 21:25:51 +0000

So how do I do read in bitbang guys. In the user terminal I used to do
[0x90 0x10 [0x91 r]
(start chip_write_addr reg_addr start chip_read_addr read )

In bitbang should I do
02 90 10 02 91 04 03

By: Peter Huewe

Peter Huewe — Wed, 03 Feb 2010 10:09:03 +0000

Hi,

Ian was so kind to change the Binary I2C mode so that it now supports I2C Speeds upto 400khz

The speed parameters are now these:
#011000xx – Set I2C speed, 11 = 400khz 10=100khz 01=50khz 00=5

Ians changes can be viewed here:
http://code.google.com/p/the-bus-pirate/source/diff?spec=svn311&r=310&format=side&path=/trunk/source/I2C.c&old_path=/trunk/source/I2C.c&old=190

I’ll update the python example soon.

By: Ian

Ian — Tue, 20 Oct 2009 05:57:11 +0000

When you do the read sequence, are you ACKing and NACKing each byte? If not, you’ll be a bit behind and have random errors.

When you do the read bytes, send an ACK if you’re going to read another byte, and a NACK if it’s the last byte before a stop condition.

By: James

James — Mon, 19 Oct 2009 19:47:16 +0000

I did find the answer for the missing chip confirmations though, with a floating I2C bus the line is low which makes the bbReadBit function return 0, when using this function to read the ACK bit after a I2C write it looks like a valid confirmation even though no chip responded.

By: James

James — Mon, 19 Oct 2009 19:04:30 +0000

Ahh, found it, sorry for making my bugs yours :)

By: James

James — Mon, 19 Oct 2009 18:30:53 +0000

Line url’s is a pretty usefull feature, I’ll go recheck, maybe I need to clear a buffer or something.

By: Ian

Ian — Mon, 19 Oct 2009 17:32:25 +0000

I double checked, but I haven’t actually run it using a terminal. I’ll take another look tomorrow. You should be getting 0×01 from 02 and 03:

http://code.google.com/p/the-bus-pirate/source/browse/trunk/source/I2C.c#486