Monitoring a device

In AEL, the Agent Engineering Language, you flash and monitor supported boards from the command line. ael monitor shows the output of one device that you select, such as the lines a program on a board writes to its serial connection.

Usage

ael monitor --device <device>
ael monitor --device <device> --json

Option	Meaning
`--device <device>`	The device to monitor, by an identity from `ael devices`.
`--json`	The device's output and events in machine-readable form.

Stop monitoring by interrupting the command, as you would any program in your terminal.

What it shows

It shows:

What the device sends, as it arrives.
Events around it: the device connecting, disconnecting or restarting.

Bounded by design

Output is bounded. The monitor limits how fast it shows output and how much it keeps, so a busy device cannot flood your terminal or your disk.
Stopping is prompt. Interrupting the monitor stops it promptly, even while the device is sending.
One user at a time. The monitor takes the device for itself while it runs. A device that is being flashed is not available to monitor until the flash has finished.

When the device goes away

If the device is unplugged or stops answering, ael monitor says so clearly and ends, rather than wait without a word. It never switches to another device on its own.

What it never does

It never flashes, resets or reconfigures the device.
It never selects a device for you: --device is required.

Listing devices: finding the device to monitor.
Flashing a board: writing a firmware image before monitoring it.
Reporting, logs and replay: structured logs from your programs.
Logging and monitoring: logs on boards, and watching a device.