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products:sbc:common:applications:gpio:i2c

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products:sbc:common:applications:gpio:i2c [2022/07/12 04:27]
nick 		products:sbc:common:applications:gpio:i2c [2023/11/07 04:51] (current)
nick [Enable I2C]
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 ===== Introduction ===== ===== Introduction =====
  
-This document mainly introduces how to use I2C bus on Khadas SBC. You will learn how to connect I2C devices, check I2C devices, and read device register values.+This page introduces the usage of I2C bus on [[products:sbc:common:applications:gpio:40pin-header|40-Pin Header]].
  
-===== Hardware Connection =====+===== I2C Information =====
  
-<tabbox VIM1/2> +|           ^  I2C     ^  PIN      ^  GPIO Name  ^  DT Overlays Node  ^  Bus Number  ^  Device Node  ^ 
-**I2C A** \\ +^  VIM1/2   |  I2C A   |  22(SCL)  |  GPIODV_25  |  i2c0              |  0           |  /dev/i2c-0   | 
-''Sensor SCL'' <-> ''I2C_SCK_A'' (PIN 22) \\ +| :::       | :::      |  23(SDA)  |  GPIODV_24  | :::                | :::          | :::           | 
-''Sensor SDA'' <-> ''I2C_SDA_A'' (PIN 23) \\ +| :::       |  I2C B   |  25(SCL)  |  GPIODV_27  |  -                 |  1           |  /dev/i2c-1   | 
-''Sensor GND'' <-> ''GND'' \\ +| :::       | :::      |  26(SDA)  |  GPIODV_26  | :::                | :::          | :::           | 
-''Sensor VCC'' <-> ''5V'' or ''3.3V'' %%//%%depends on your sensor \\ +^  VIM3/3L  |  I2CM 3  |  22(SCL)  |  GPIOA_15   |  i2c3              |  3           |  /dev/i2c-3   | 
-**I2C B** \\ +| :::       | :::      |  23(SDA)  |  GPIOA_14   | :::                | :::          | :::           | 
-''Sensor SCL'' <-> ''I2C_SCK_B'' (PIN 25) \\ +| :::       |  I2C AO  |  25(SCL)  |  GPIOAO_2   |  -                 |  4           |  /dev/i2c-4   | 
-''Sensor SDA'' <-> ''I2C_SDA_B'' (PIN 26) \\ +| :::       | :::      |  26(SDA)  |  GPIOAO_3   | :::                | :::          | :::           | 
-''Sensor GND'' <-> ''GND'' \\ +^  VIM4     |  I2CM F  |  22(SCL)  |  GPIOY_17   |  i2cm_f            |  5           |  /dev/i2c-5   | 
-''Sensor VCC'' <-> ''5V'' or ''3.3V'' %%//%%depends on your sensor +| :::       | :::      |  23(SDA)  |  GPIOY_18   | :::                | :::          | :::           | 
-<tabbox VIM3/3L> +| :::       |  I2CM A  |  25(SCL)  |  GPIOT_20   |  i2cm_a            |  0           |  /dev/i2c-0   | 
-**I2C 3** \\ +| :::       | :::      |  26(SDA)  |  GPIOT_21   | :::                | :::          | :::           | 
-''Sensor SCL'' <-> ''I2C0_SCK'' (PIN 22) \\ +^  VIM1S    |  I2CM B  |  22(SCL)  |  GPIOD_7    |  -                 |  1           |  /dev/i2c-1   | 
-''Sensor SDA'' <-> ''I2C0_SDA'' (PIN 23) \\ +| :::       | :::      |  23(SDA)  |  GPIOD_6    | :::                | :::          | :::           | 
-''Sensor GND'' <-> ''GND'' \\ +| :::       |  I2CM E  |  25(SCL)  |  GPIOZ_11   |  i2cm_e            |  4           |  /dev/i2c-4   | 
-''Sensor VCC'' <-> ''5V'' or ''3.3V'' %%//%%depends on your sensor \\ +| :::       | :::      |  26(SDA)  |  GPIOZ_12   | :::                | :::          | :::           |
-**I2C 4** \\ +
-''Sensor SCL'' <-> ''I2C1_SCK'' (PIN 25) \\ +
-''Sensor SDA'' <-> ''I2C1_SDA'' (PIN 26) \\ +
-''Sensor GND'' <-> ''GND'' \\ +
-''Sensor VCC'' <-> ''5V'' or ''3.3V'' %%//%%depends on your sensor +
-<tabbox VIM4> +
-**I2CM A** \\ +
-''Sensor SCL'' <-> ''I2CM_A_SCL'' (PIN 25) \\ +
-''Sensor SDA'' <-> ''I2CM_A_SDA'' (PIN 26) \\ +
-''Sensor GND'' <-> ''GND'' \\ +
-''Sensor VCC'' <-> ''5V'' or ''3.3V'' %%//%%depends on your sensor \\ +
-**I2CM F** \\ +
-''Sensor SCL'' <-> ''I2CM_F_SCL'' (PIN 22) \\ +
-''Sensor SDA'' <-> ''I2CM_F_SDA'' (PIN 23) \\ +
-''Sensor GND'' <-> ''GND'' \\ +
-''Sensor VCC'' <-> ''5V'' or ''3.3V'' %%//%%depends on your sensor+
  
- +===== Enable I2C =====
-^  I2C    ^  PIN & GPIO Number                                             ^  DT Overlays Node  ^  Bus Number  ^  Device Node  ^ +
-| I2CM A  | SCL - PIN25 - GPIOT_20 (#466)\\ SDA - PIN26 - GPIOT_21 (#467)  |  i2cm_a            |  0           |  /dev/i2c-0   | +
-| I2CM F  | SCL - PIN22 - GPIOY_17 (#501)\\ SDA - PIN23 - GPIOY_18 (#502)  |  i2cm_f            |  5           |  /dev/i2c-5   | +
- +
- +
-</tabbox> +
- +
-===== Enabel I2C =====+
  
 In order to use the I2C, you need to enable the I2C function via [[products:sbc:common:configurations:device-tree-overlay|Device Tree Overlay]]. In order to use the I2C, you need to enable the I2C function via [[products:sbc:common:configurations:device-tree-overlay|Device Tree Overlay]].
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 <tabbox VIM1/2/3/3L/Edge1> <tabbox VIM1/2/3/3L/Edge1>
  
-Edit ''/boot/env.txt'' to add the i2c node to ''overlays'' node.+Edit ''/boot/env.txt'' to add the i2c node to ''overlays'' node if it doesn't exist.
  
-Take VIM3 as an example to enable ''i2c3'':+Take VIM3 as an example to enable ''I2CM 3'', you need to add ''i2c3'' node to ''overlays'' node if it doesn't exist.
  
 ```shell ```shell
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 ```shell ```shell
-khadas@Khadas:~$ ls /dev/i2c-3+$ ls /dev/i2c-3
 /dev/i2c-3 /dev/i2c-3
 ``` ```
 +
 +<tabbox VIM3 with 5.15 kernel>
 +
 +Edit ''/boot/dtb/amlogic/kvim3.dtb.overlay.env'' to add i2c node to ''fdt_overlays'' node if it doesn't exist.
 +
 +
 +e.g. To enable ''I2CM 3'', you need to add ''i2c3'' to node ''fdt_overlays'' if it doesn't exist.
 +
 +```shell
 +fdt_overlays=i2c3
 +
 +```
 +
 +After reboot, you will see the I2C device node.
 +
 +<tabbox VIM3L with 5.15 kernel>
 +
 +Edit ''/boot/dtb/amlogic/kvim3l.dtb.overlay.env'' to add i2c node to ''fdt_overlays'' node if it doesn't exist.
 +
 +
 +e.g. To enable ''I2CM 3'', you need to add ''i2c3'' to node ''fdt_overlays'' if it doesn't exist.
 +
 +```shell
 +fdt_overlays=i2c3
 +
 +```
 +
 +After reboot, you will see the I2C device node.
  
 <tabbox VIM4> <tabbox VIM4>
  
-Edit ''/boot/dtb/amlogic/kvim4.dtb.overlay.env'' to add i2c node to ''fdt_overlays'' node.+Edit ''/boot/dtb/amlogic/kvim4.dtb.overlay.env'' to add i2c node to ''fdt_overlays'' node if it doesn't exist.
  
  
-e.g. Enable ''I2CM A'', you need to add ''i2cm_a'' to node ''fdt_overlays''.+e.g. To enable ''I2CM A'', you need to add ''i2cm_a'' to node ''fdt_overlays'' if it doesn't exist.
  
 ```shell ```shell
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 ```shell ```shell
-khadas@Khadas:~$ ls /dev/i2c-0+$ ls /dev/i2c-0
 /dev/i2c-0 /dev/i2c-0
 +```
 +
 +<tabbox VIM1S>
 +
 +Edit ''/boot/dtb/amlogic/kvim1s.dtb.overlay.env'' to add i2c node to ''fdt_overlays'' node if it doesn't exist.
 +
 +
 +e.g. To enable ''I2CM E'', you need to add ''i2cm_e'' to node ''fdt_overlays'' if it doesn't exist.
 +
 +```shell
 +fdt_overlays=i2cm_e
 +
 +```
 +
 +After reboot, you will see the I2C device node.
 +
 +```shell
 +$ ls /dev/i2c-4
 +/dev/i2c-4
 ``` ```
  
 </tabbox> </tabbox>
 +
 +===== I2C Usage =====
 +
 +Please check the [[https://manpages.ubuntu.com/manpages/jammy/en/man8/i2cdetect.8.html|I2C Usage]].
  
  
 ===== Disable I2C to Use GPIO ===== ===== Disable I2C to Use GPIO =====
  
-If you want to use normal GPIO instead of I2C, you can remove the I2C node in device tree overlays configration file. +If you want to use normal GPIO instead of I2C, you can remove the I2C node in [[products:sbc:common:configurations:device-tree-overlay|Device Tree Overlay]]. 
Last modified: 2022/07/12 04:27 by nick

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