PIO CLI tool

This command line tool enables you to query and control the various interfaces supported by Peripheral I/O. You can use this tool to do the following:

Easily discover the pin names for a given developer board
Ensure peripheral devices are connected to the board correctly
Run basic functionality tests as well as scripted tests

Use an adb shell to access this tool.

Command reference

Issue commands from a command line on your development machine or from a script. The usage is:

pio command [arg]

where command can be one of the following:

Command	Description
`gpio`	General Purpose Input/Output (GPIO) pin control
`i2c`	Inter-Integrated Circuit (I2C) bus control
`list`	List all of the available interfaces. Optionally, provide a type of device to only list those device types.
`pwm`	Pulse Width Modulation (PWM) device control
`spi`	Serial Peripheral Interface (SPI) device control
`uart`	Universal Asynchronous Receiver Transmitter (UART) device control

List command

Usage

pio list [device]

To list only devices of a certain type, specify device to be one of the following:

gpio
i2c
pwm
spi
uart

Example

$ pio list
gpio GPIO1_IO10
pwm PWM1
spi SPI3.0

$ pio list gpio
GPIO1_IO10

GPIO command

Usage

pio gpio name subcommand [arg]

name is the name of a valid GPIO pin.

subcommand can be one of the following:

Subcommand	Description
`write`	Set the GPIO output state. Use `0` or `1` to designate the low or high logic state.
`read`	Read from the specified GPIO.

Example

$ pio gpio GPIO1_IO10 write 0
$ pio gpio GPIO2_IO07 read
1

I2C command

Usage

pio i2c name address subcommand [arg]

name is the name of a valid I2C bus.

address is the address of an I2C device.

subcommand can be one of the following:

Subcommand	Description
`read-raw size`	Read `size` bytes from device.
`read-reg-byte reg`	Read a byte from `reg`.
`read-reg-word reg`	Read a word (2 bytes) from `reg`.
`read-reg-buffer reg size`	Read `size` bytes from `reg`.
`write-raw val [val ...]`	Write `val` to device.
`write-reg-byte reg val`	Write byte `val` to `reg`.
`write-reg-word reg val`	Write word `val` to `reg`.
`write-reg-buffer reg val [val ...]`	Write `val` to `reg`.

Example

$ pio i2c I2C1 0x10 write-reg-byte 0x20 0x40
$ pio i2c I2C1 0x12 read-reg-byte 0x24
0x7F

PWM command

Usage

pio pwm name subcommand [arg] [opt]

name is the name of a valid PWM interface.

subcommand can be the following:

Subcommand	Description
`enable`	Enable or disable the PWM. Use `0` or `1` to disable or enable the PWM.

opt can be any combination of the following:

Option	Description
`--duty`	Sets the duty cycle. Default is 50.0. Use a number from 0 to 100.0.
`--freq`	Sets the frequency (in Hertz). Default is 100. Use a positive number.

Example

$ pio pwm PWM1 enable 1 --duty=55.0 --freq=200

SPI command

Usage

pio spi name subcommand arg [opt]

name is the name of a valid SPI interface.

subcommand can be one of the following:

Subcommand	Description
`write val [val ...] [opt ...]`	Write `val` with `opt` (optional parameters) to device.
`read size [opt ...]`	Read `size` characters with `opt` from device.
`transfer val [val ...] [opt ...]`	Write `val` to device with `opt`. Read an equal number of characters with `opt` from device.

opt can be any combination of the following:

Option	Description
`--freq`	Sets the frequency (in Hertz). Default is 200,000. Use a number.
`--mode`	Sets the device mode. Default is mode 0. `0: [CPHA=0, CPOL=0]` `1: [CPHA=1, CPOL=0]` `2: [CPHA=0, CPOL=1]` `3: [CPHA=1, CPOL=1]`
`--bits`	Sets the bits per word. Default is 8. Use a number.
`--just`	Sets bit justification to LSB or MSB. Default is `msb`. Set to `lsb` or `msb`.

Example

$ pio spi SPI3.0 write 0x20 0x40 --freq=250000
$ pio spi SPI3.1 transfer 0xD0 0x00 --just=lsb
0x00 0xDE

UART command

Usage

pio uart name subcommand [opt]

name is the name of a valid UART device.

subcommand can be one of the following:

Subcommand	Description
`write opt`	Write stdin to device.
`read opt`	Read from UART device.
`transfer opt`	Write to and read from the UART device.

opt can be any combination of the following:

Option	Description
`--readlen`	Number of characters to read from the device, only for `read` and `transfer`. Default is indefinite. Use a number.
`--baud`	Sets the baud rate (in Hertz). Default is 9600. Use a number.
`--stop`	Sets the number of stop bits. Default is 1. Use a number.
`--bits`	Sets the size of a character for the UART device. Default is 8. Use a number.
`--parity`	Sets the parity mode. Default is `N`: None. `N`: None `E`: Even `O`: Odd `M`: Mark `S`: Space

Example

$ pio uart UART6 write --baud=9600 --bits=8 --stop=1 --parity=N # Input from file, pipe, or stdin
$ cat file.txt | pio uart UART6 write --baud=9600 --bits=8 --stop=1 --parity=N