README
¶
I2C bus setting up and usage for linux on RPi device and respective clones
This library written in Go programming language intended to activate and interact with the I2C bus by reading and writing data.
Compatibility
Tested on Raspberry PI 1 (model B) and Banana PI (model M1).
Golang usage
func main() {
// Create new connection to I2C bus on 2 line with address 0x27
i2c, err := i2c.NewI2C(0x27, 2)
if err != nil { log.Fatal(err) }
// Free I2C connection on exit
defer i2c.Close()
....
// Here goes code specific for sending and reading data
// to and from device connected via I2C bus, like:
_, err := i2c.Write([]byte{0x1, 0xF3})
if err != nil { log.Fatal(err) }
....
}
Getting help
GoDoc documentation
Troubleshoting
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How to obtain fresh Golang installation to RPi device (either any RPi clone): If your RaspberryPI golang installation taken by default from repository is outdated, you may consider to install actual golang mannualy from official Golang site. Download tar.gz file containing armv6l in the name. Follow installation instructions.
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How to enable I2C bus on RPi device: If you employ RaspberryPI, use raspi-config utility to activate i2c-bus on the OS level. Go to "Interfaceing Options" menu, to active I2C bus. Probably you will need to reboot to load i2c kernel module. Finally you should have device like /dev/i2c-1 present in the system.
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How to find I2C bus allocation and device address: Use i2cdetect utility in format "i2cdetect -y X", where X may vary from 0 to 5 or more, to discover address occupied by peripheral device. To install utility you should run
apt install i2c-toolson debian-kind system.i2detect -y 1sample output:0 1 2 3 4 5 6 7 8 9 a b c d e f 00: -- -- -- -- -- -- -- -- -- -- -- -- -- 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 70: -- -- -- -- -- -- 76 --
License
Go-i2c is licensed inder MIT License.
Documentation
¶
Overview ¶
Package i2c provides low level control over the linux i2c bus.
Before usage you should load the i2c-dev kernel module
sudo modprobe i2c-dev
Each i2c bus can address 127 independent i2c devices, and most linux systems contain several buses.
Index ¶
- Constants
- type I2C
- func (v *I2C) Close() error
- func (v *I2C) ReadBytes(buf []byte) (int, error)
- func (v *I2C) ReadRegBytes(reg byte, n int) ([]byte, int, error)
- func (v *I2C) ReadRegS16BE(reg byte) (int16, error)
- func (v *I2C) ReadRegS16LE(reg byte) (int16, error)
- func (v *I2C) ReadRegU16BE(reg byte) (uint16, error)
- func (v *I2C) ReadRegU16LE(reg byte) (uint16, error)
- func (v *I2C) ReadRegU8(reg byte) (byte, error)
- func (v *I2C) WriteBytes(buf []byte) (int, error)
- func (v *I2C) WriteRegS16BE(reg byte, value int16) error
- func (v *I2C) WriteRegS16LE(reg byte, value int16) error
- func (v *I2C) WriteRegU16BE(reg byte, value uint16) error
- func (v *I2C) WriteRegU16LE(reg byte, value uint16) error
- func (v *I2C) WriteRegU8(reg byte, value byte) error
Constants ¶
const (
I2C_SLAVE = 0x0703
)
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type I2C ¶
type I2C struct {
// Enable verbose output
Debug bool
// contains filtered or unexported fields
}
I2C represents a connection to an i2c device.
func (*I2C) ReadRegBytes ¶
SMBus (System Management Bus) protocol over I2C. Read count of n byte's sequence from i2c device starting from reg address.
func (*I2C) ReadRegS16BE ¶
SMBus (System Management Bus) protocol over I2C. Read signed big endian word (16 bits) from i2c device starting from address specified in reg.
func (*I2C) ReadRegS16LE ¶
SMBus (System Management Bus) protocol over I2C. Read unsigned little endian word (16 bits) from i2c device starting from address specified in reg.
func (*I2C) ReadRegU16BE ¶
SMBus (System Management Bus) protocol over I2C. Read unsigned big endian word (16 bits) from i2c device starting from address specified in reg.
func (*I2C) ReadRegU16LE ¶
SMBus (System Management Bus) protocol over I2C. Read unsigned little endian word (16 bits) from i2c device starting from address specified in reg.
func (*I2C) ReadRegU8 ¶
SMBus (System Management Bus) protocol over I2C. Read byte from i2c device register specified in reg.
func (*I2C) WriteBytes ¶
Write sends buf to the remote i2c device. The interpretation of the message is implementation dependant.
func (*I2C) WriteRegS16BE ¶
SMBus (System Management Bus) protocol over I2C. Write signed big endian word (16 bits) value to i2c device starting from address specified in reg.
func (*I2C) WriteRegS16LE ¶
SMBus (System Management Bus) protocol over I2C. Write signed big endian word (16 bits) value to i2c device starting from address specified in reg.
func (*I2C) WriteRegU16BE ¶
SMBus (System Management Bus) protocol over I2C. Write unsigned big endian word (16 bits) value to i2c device starting from address specified in reg.
func (*I2C) WriteRegU16LE ¶
SMBus (System Management Bus) protocol over I2C. Write unsigned big endian word (16 bits) value to i2c device starting from address specified in reg.
Source Files