I2C: Diferență între versiuni

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==Link-uri externe==
==Link-uri externe==
===Documentație===
* [https://www.nxp.com/docs/en/application-note/AN4471.pdf SMBus Quick Start Guide] — The System Management Bus (SMBus) is a two-wire
interface through which various system component chips can communicate with each other and with the rest of the 4 system. It is based on the principles of operation of I2C. SMBus provides a control bus for the system to pass messages to and from devices instead of using individual control lines, helping to reduce pin count and system wires.
===Specificații===
===Specificații===
* [https://github.com/raspberrypi/hats/blob/master/eeprom-format.md B+ HAT ID EEPROM Format Specification]
* [https://github.com/raspberrypi/hats/blob/master/eeprom-format.md B+ HAT ID EEPROM Format Specification]

Versiunea de la data 23 iulie 2020 17:34

I2C Probing

tom@raspberrypi:~ $ sudo i2cdetect -F 0
Functionalities implemented by /dev/i2c-0:
I2C                              yes
SMBus Quick Command              yes
SMBus Send Byte                  yes
SMBus Receive Byte               yes
SMBus Write Byte                 yes
SMBus Read Byte                  yes
SMBus Write Word                 yes
SMBus Read Word                  yes
SMBus Process Call               yes
SMBus Block Write                yes
SMBus Block Read                 no
SMBus Block Process Call         no
SMBus PEC                        yes
I2C Block Write                  yes
I2C Block Read                   yes

i2cdetect is a userspace program to scan an I2C bus for devices. It outputs a table with the list of detected devices on the specified bus. i2cbus indicates the number or name of the I2C bus to be scanned, and should correspond to one of the busses listed by i2cdetect -l. The optional parameters first and last restrict the scanning range (default: from 0x03 to 0x77).

tom@raspberrypi:~ $ sudo i2cdetect -l
i2c-1	i2c       	bcm2835 (i2c@7e804000)          	I2C adapter
i2c-11	i2c       	bcm2835 (i2c@7e205000)          	I2C adapter
i2c-0	i2c       	i2c-11-mux (chan_id 0)          	I2C adapter
i2c-10	i2c       	i2c-11-mux (chan_id 1)          	I2C adapter
tom@raspberrypi:~ $ sudo i2cdetect -y 0
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          -- -- -- -- -- -- -- -- -- -- -- -- -- 
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
50: 50 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
70: -- -- -- -- -- -- -- --

Documentație

interface through which various system component chips can communicate with each other and with the rest of the 4 system. It is based on the principles of operation of I2C. SMBus provides a control bus for the system to pass messages to and from devices instead of using individual control lines, helping to reduce pin count and system wires.

Specificații

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