1.\" 2.\" SPDX-License-Identifier: BSD-2-Clause 3.\" 4.\" Copyright (c) 2024 Denis Bodor <dbodor@rollmops.ninja> 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25.\" SUCH DAMAGE. 26.\" 27.Dd February 18, 2024 28.Dt I2CTINYUSB 4 29.Os 30.Sh NAME 31.Nm i2ctinyusb 32.Nd driver for a USB / I2C bridge device 33.Sh SYNOPSIS 34To compile this driver into the kernel, 35place the following lines in your 36kernel configuration file: 37.Bd -ragged -offset indent 38.Cd "device i2ctinyusb" 39.Cd "device usb" 40.Cd "device iicbus" 41.Ed 42.Pp 43Alternatively, to load the driver as a 44module at boot time, place the following line in 45.Xr loader.conf 5 : 46.Bd -literal -offset indent 47i2ctinyusb_load="YES" 48.Ed 49.Sh DESCRIPTION 50The 51.Nm 52driver provides support for the device designed by Till Harbaum known 53as i2c-tiny-usb. This is initially a very simple circuit built with 54an Atmel AVR ATtiny45, but a Raspberry Pi Pico (RP2040) implementation 55also exists. 56.Pp 57The 58.Nm 59driver creates a 60.Xr iicbus 4 61child bus to expose the iic functions, enabling I2C sensors, converters 62and displays to be connected to any computer with a USB port. 63.Pp 64More information about this device can be found at: 65.Bd -literal -offset indent 66https://github.com/harbaum/I2C-Tiny-USB 67.Ed 68.Pp 69and (for the Raspberry Pi Pico version): 70.Bd -literal -offset indent 71https://github.com/Nicolai-Electronics/rp2040-i2c-interface 72.Ed 73.Pp 74The I2C controller supports read and write transactions with up to 1024 75bytes of data, and a write followed by the repeated start followed by a 76read transactions up to 1024 bytes. 77Zero length transfers are not supported. 78.Sh SEE ALSO 79.Xr iicbus 4 , 80.Xr usb 4 81.Sh HISTORY 82The 83.Nm 84driver and this manual page was written by 85.An Denis Bodor Aq Mt dbodor@rollmops.ninja . 86