Version: 2.0

OpenArm CAN CLI Tool

openarm-can-cli is a command-line tool for configuring and monitoring DaMiao motors over CAN/CAN-FD interfaces.

Prerequisites

Install

sudo apt install -y libopenarm-can-dev openarm-can-utils

For manual installation or other platforms, see the build guide.

Verify the socketcan interface is available:

ip link show | grep can

Quick Start

1. Configure the CAN interface

Before communicating with motors, configure the CAN interface baudrate to match your motors.

# Default: 1Mbps nominal, 5Mbps data, CAN-FD
openarm-can-cli -i can0 can_configure

# Classic CAN (1Mbps only, no FD)
openarm-can-cli -i can0 can_configure --no-fd

2. Discover connected motors

openarm-can-cli -i can0 discover

3. Enable motors and check status

# Enable all arm motors (IDs 1-8)
openarm-can-cli -i can0 enable

# Monitor motor status
openarm-can-cli -i can0 monitor

Global Options

Option	Description	Default
`-i, --interface`	SocketCAN interface	`can0`
`-h, --help`	Print help message

The -i option applies to all subcommands:

openarm-can-cli -i can1 monitor

Subcommands

`can_configure` — Configure CAN Interface

Set up the SocketCAN interface baudrate and mode.

openarm-can-cli -i can0 can_configure [OPTIONS]

Option	Description	Default
`-b, --bitrate`	Nominal (arbitration) bitrate	`1000000`
`-d, --dbitrate`	Data phase bitrate (CAN-FD)	`5000000`
`--sp`	Sample point for nominal phase	`0.75`
`--dsp`	Sample point for data phase	`0.75`
`--dsjw`	Data SJW	`2`
`--rm`	Auto-restart time (ms)	`100`
`--no-fd`	Disable CAN-FD mode

Examples:

# Default (1Mbps / 5Mbps FD)
openarm-can-cli -i can0 can_configure

# 8Mbps data rate
openarm-can-cli -i can0 can_configure -d 8000000 --dsp 0.6 --dsjw 1

# Classic CAN (no FD)
openarm-can-cli -i can0 can_configure --no-fd

note

When -i is not specified, can_configure applies to all interfaces (can0–can3).

`discover` — Scan for Motors

Scan the CAN bus for connected motors.

openarm-can-cli -i can0 discover [OPTIONS]

Option	Description	Default
`-m, --max-id`	Maximum motor ID to scan	`16`
`--full-scan`	Scan all 12 baudrates	Fast scan (1M/5M/8M/10M)

Examples:

# Fast scan (recommended)
openarm-can-cli -i can0 discover

# Full scan (slower but more thorough)
openarm-can-cli -i can0 discover --full-scan

# Scan up to ID 32
openarm-can-cli -i can0 discover -m 32

Example output:

=========================================================
 DISCOVERY SUMMARY (Total: 8 motors found)
---------------------------------------------------------
Send ID     Recv ID     Internal Baudrate Setting
---------------------------------------------------------
0x01        0x11        5 Mbps (FD) (Code: 9)
0x02        0x12        5 Mbps (FD) (Code: 9)
...
=========================================================
⚠️  WARNING: CAN interface is now configured at 10 Mbps (FD).
   Run 'can_configure' to restore the baudrate for your motors.

note

After discover, always run can_configure to restore the correct baudrate before using other commands.

`show_param` — Read Motor Parameters

Read all internal parameters from motors.

openarm-can-cli -i can0 show_param [OPTIONS]

Option	Description	Default
`-a, --arm`	Read from arm motors (IDs 1-8)	enabled
`--id`	Specific motor IDs

Examples:

# Read parameters from all arm motors
openarm-can-cli -i can0 show_param

# Read from specific motors
openarm-can-cli -i can0 show_param --id 1,2,3
openarm-can-cli -i can0 show_param --id 1 2 3

Example output:

==================================================
 MOTOR ID: 0x1 (Response ID: 0x11)
==================================================
Parameter                      R/W  Type      Range                Value
--------------------------------------------------------------------------------
Master ID                      RW   uint32    [0, 0x7FF]           17
Motor (ESC) ID                 RW   uint32    [0, 0x7FF]           1
Control Mode                   RW   uint32    [0, 4]               1 (MIT)
CAN Baudrate                   RW   uint32    [0, 9]               9 (5M)
...

`write_param` — Write Motor Parameter

Write a value to a specific motor register.

openarm-can-cli -i can0 write_param -c <ID> -r <RID> -v <VALUE> [--save]

Option	Description
`-c, --id`	Target motor ID (required)
`-r, --rid`	Register ID (required)
`-v, --value`	Value to write (required)
`--save`	Save to flash (⚠️ limit: ~10,000 cycles)

Example:

# Set control mode to MIT (RID=10, value=1)
openarm-can-cli -i can0 write_param -c 1 -r 10 -v 1

`enable` / `disable` — Motor Power Control

Enable or disable motor torque output.

openarm-can-cli -i can0 enable [OPTIONS]
openarm-can-cli -i can0 disable [OPTIONS]

Option	Description	Default
`-a, --arm`	All arm motors (IDs 1-8)	enabled
`--id`	Specific motor IDs

Examples:

# Enable all arm motors
openarm-can-cli -i can0 enable

# Enable specific motors
openarm-can-cli -i can0 enable --id 1,2,3

# Disable all arm motors
openarm-can-cli -i can0 disable

`monitor` — Live Telemetry Dashboard

Display real-time motor position, velocity, torque, and temperature.

openarm-can-cli -i can0 monitor [OPTIONS]

Option	Description	Default
`-a, --arm`	Monitor arm motors (IDs 1-8)	enabled
`--id`	Specific motor IDs
`-t, --tick`	Update interval (ms)	`100`
`-d, --duration`	Total duration (ms)	`6000`

Examples:

# Monitor all arm motors for 6 seconds
openarm-can-cli -i can0 monitor

# Monitor specific motors
openarm-can-cli -i can0 monitor --id 1,2,3

# Monitor for 30 seconds with 50ms update interval
openarm-can-cli -i can0 monitor -d 30000 -t 50

`change_baud` — Change Motor Baudrate

Change the internal CAN baudrate of a motor.

openarm-can-cli -i can0 change_baud -b <BAUDRATE> -c <ID> [--save]

Option	Description
`-b, --baudrate`	Target baudrate (required)
`-c, --canid`	Motor ID (required)
`--save`	Save to flash (⚠️ limit: ~10,000 cycles)

Supported baudrates:

Code	Baudrate
0	125K
1	200K
2	250K
3	500K
4	1M
5	2M
6	2.5M
7	3.2M
8	4M
9	5M
10	8M
11	10M

Example:

# 1. First, configure the interface to match the motor's CURRENT baudrate
openarm-can-cli -i can0 can_configure -d 5000000  # if motor is currently at 5Mbps

# 2. Change motor baudrate and save
openarm-can-cli -i can0 change_baud -b 8000000 -c 3 --save

# 3. Power cycle the motor

# 4. Reconfigure interface to the NEW baudrate
openarm-can-cli -i can0 can_configure -d 8000000

danger

Always configure the CAN interface to match the motor's current baudrate before running this command. If they don't match, the command will not reach the motor.
The --save flag writes to flash memory. Flash memory has a hard limit of ~10,000 write cycles. Do not run --save in a loop or repeatedly. Exceeding this limit will permanently damage the motor's flash memory.
After saving, a power cycle is required for the new baudrate to take effect.

`change_id` — Change Motor CAN ID

Change the Slave ID and Master ID of a motor.

openarm-can-cli -i can0 change_id -c <CURRENT_ID> -s <NEW_SLAVE_ID> [OPTIONS]

Option	Description	Default
`-c, --current`	Current Slave ID (required)
`-s, --new-slave`	New Slave ID (required)
`-m, --new-master`	New Master ID	`17`
`--save`	Save to flash

Example:

# Change motor ID from 5 to 6
openarm-can-cli -i can0 change_id -c 5 -s 6 --save

danger

Always configure the CAN interface to match the motor's current baudrate before running this command.
If two motors on the same bus share the same ID, CAN communication will fail. Make sure all motor IDs on a bus are unique before enabling them. Use discover to check current IDs.
The --save flag writes to flash memory. Flash memory has a hard limit of ~10,000 write cycles. Do not run --save repeatedly.

`set_zero` — Set Motor Zero Position

# Set zero for all arm motors
openarm-can-cli -i can0 set_zero

# Set zero for specific motors
openarm-can-cli -i can0 set_zero --id 1,2

`clear_error` — Clear Motor Errors

Reset motor error flags.

openarm-can-cli -i can0 clear_error [OPTIONS]

Option	Description	Default
`-a, --arm`	Clear errors on arm motors (IDs 1-8)	enabled
`--id`	Specific motor IDs

Common Workflows

First-time motor connection

# 1. Configure interface (match your motor baudrate)
openarm-can-cli -i can0 can_configure

# 2. Discover motors and check baudrates
openarm-can-cli -i can0 discover

# 3. Restore interface to motor baudrate after discover
openarm-can-cli -i can0 can_configure

# 4. Check motor parameters
openarm-can-cli -i can0 show_param

# 5. Enable and monitor
openarm-can-cli -i can0 enable
openarm-can-cli -i can0 monitor

Change motor baudrate from 5Mbps to 8Mbps

# 1. Configure interface to current motor baudrate (5Mbps)
openarm-can-cli -i can0 can_configure -d 5000000

# 2. Change motor baudrate
openarm-can-cli -i can0 change_baud -b 8000000 -c 1 --save

# 3. Power cycle the motor

# 4. Reconfigure interface to new baudrate
openarm-can-cli -i can0 can_configure -d 8000000 --dsp 0.6 --dsjw 1

Troubleshooting

General Checklist

Before diving into specific issues, go through this checklist:

Motor power is on
CAN cable is connected and not broken
CAN interface baudrate matches the motor's internal baudrate
Termination resistors (120Ω) are connected at both ends of the bus
All motor IDs on the bus are unique
CAN driver is loaded

No motors found in `discover`

Go through the general checklist above

Try --full-scan to scan all baudrates:

openarm-can-cli -i can0 discover --full-scan

`show_param` shows no response

[!] NO RESPONSE FROM MOTOR - possible causes:
    - CAN cable not connected
    - Motor power not on
    - Baudrate mismatch (run 'discover' to find correct baudrate)
    - Wrong motor ID

Run discover to find the correct baudrate and motor IDs, then reconfigure the interface:

openarm-can-cli -i can0 discover
openarm-can-cli -i can0 can_configure -d <BAUDRATE_FROM_DISCOVER>

BUS OFF errors in `dmesg`

dmesg | grep -i "bus-off"

Go through the general checklist above

Try adjusting sample point settings:

openarm-can-cli -i can0 can_configure -d 8000000 --dsp 0.6 --dsjw 1

If using high baudrates (8Mbps+), shorten the cable length

`change_baud` not taking effect

Go through the general checklist above
Ensure interface baudrate matches motor's current baudrate before running
After --save, power cycle the motor
Use candump to verify frames and responses:
```
candump can0
```
A successful flash save shows a response frame from the motor (e.g. 0x11 for motor ID 1).

Prerequisites​

Install​

Quick Start​

1. Configure the CAN interface​

2. Discover connected motors​

3. Enable motors and check status​

Global Options​

Subcommands​

can_configure — Configure CAN Interface​

discover — Scan for Motors​

show_param — Read Motor Parameters​

write_param — Write Motor Parameter​

enable / disable — Motor Power Control​

monitor — Live Telemetry Dashboard​

change_baud — Change Motor Baudrate​

change_id — Change Motor CAN ID​

set_zero — Set Motor Zero Position​

clear_error — Clear Motor Errors​

Common Workflows​

First-time motor connection​

Change motor baudrate from 5Mbps to 8Mbps​

Troubleshooting​

General Checklist​

No motors found in discover​

show_param shows no response​

BUS OFF errors in dmesg​

change_baud not taking effect​

Prerequisites

Install

Quick Start

1. Configure the CAN interface

2. Discover connected motors

3. Enable motors and check status

Global Options

Subcommands

`can_configure` — Configure CAN Interface

`discover` — Scan for Motors

`show_param` — Read Motor Parameters

`write_param` — Write Motor Parameter

`enable` / `disable` — Motor Power Control

`monitor` — Live Telemetry Dashboard

`change_baud` — Change Motor Baudrate

`change_id` — Change Motor CAN ID

`set_zero` — Set Motor Zero Position

`clear_error` — Clear Motor Errors

Common Workflows

First-time motor connection

Change motor baudrate from 5Mbps to 8Mbps

Troubleshooting

General Checklist

No motors found in `discover`

`show_param` shows no response

BUS OFF errors in `dmesg`

`change_baud` not taking effect