The board over Wi-Fi¶

Once the board is on your Wi-Fi, it serves a web app. It works on a phone or a computer, with nothing to install. Everything the app does is an HTTP API call, so a script can do the same.

On a phone, Status, Show, Holo and Scenes are tabs along the bottom, and the other pages are under More. On a computer, the side bar lists them all.

Each page keeps up by itself. When the board changes, from the console, a script, a scene ending or another browser, every open page shows it at once. Up to three tabs follow the board this way; a fourth checks every few seconds instead.

Scenes¶

A scene is what the screen shows, what the LEDs do and how the holo moves, saved together under a name. A scene can include any of the three parts. A scene with only the LEDs is an LED preset, and one with only a clip plays that clip.

To make one:

1. On the Scenes page, choose New scene.
2. Tick the parts it has. Fill from what's showing now copies whatever the board is doing now.
3. Try it applies the scene without saving it. Save keeps it.

When it ends says what happens once the scene is over:

• Leave it as it is: everything carries on as the scene left it.
• Go back to before: the screen, the LEDs and the holo return to what they were doing before the scene. A twitching holo twitches again, and a looping clip plays again.
• All off: the screen and LEDs go off, and the holo's servos go limp.

A scene ends when its clip has played (once, or its number of times), or after the seconds given, whichever is first, so "go back" and "all off" need a clip that doesn't play over and over, or seconds. While such a scene runs, the Scenes page shows it with End it now, which does what it would do at its end. Applying another scene, or showing something else in place of its clip, ends it without that.

Start with it makes the board apply that scene every time it starts. The board keeps 16 scenes. The console's scene command lists and applies them too: see Console commands.

Calibrating the holo¶

The holo moves only within each servo's saved travel. To set the travel:

1. On the Holo page, choose Calibrate on a servo.
2. Move the slider until the holo is at full left (or, for tilt, full down), and choose Set the closed end here.
3. Move it to full right (or up), and choose Set the open end here.
4. Choose Save the travel. The board keeps it across restarts.

Forget it goes back to the firmware's default travel. The drive policy sets whether a servo keeps being driven once it has settled. Letting go at an end stops the buzz of a servo held against its stop.

Reaching it¶

On your network¶

First, put the board on your Wi-Fi from its console. It remembers the network and rejoins it at every boot:

wifi_save <ssid> <passphrase>

Then ask the board where to find it:

web

web: on
  http://10.0.19.118/
  http://holo-2db0.local/
password: none: anyone on the network can update the board

Either address works:

• http://holo-xxxx.local/: xxxx is the end of the board's MAC address, so each board has its own name. This works from macOS, iOS, Windows and Linux, and from most Android phones. To name the board yourself, use web hostname <name>.
• The address itself: always works. Your router's device list shows it too, under the same name.

With no network: the board's own access point¶

Out in the field, the board can be the network. It turns its own access point on by itself:

• at start, when it can't join a network: none is saved, or the one it rejoins hasn't answered within 20 seconds;
• when you press BOOT (the board's BOOT button, GPIO0, also on P2 pin 4) while it isn't on a network. It first tries the saved network again; if that hasn't worked 20 seconds later, the access point comes on. A press while it is already on starts its time over.

Either way, it turns off again after 5 minutes, whether or not anyone is on it. Meanwhile the board keeps trying its network. To keep the access point on, turn it on yourself: on the Network page, or on the console:

wifi ap on

I (59133) wifi_ap: access point holo-2db0 up at 192.168.4.1
ap: on, holo-2db0, channel 11, 0 clients
pass: taxg-kerx-k4cp
page: http://192.168.4.1/

Then:

1. Join holo-xxxx from your phone or laptop with the passphrase shown.
2. The phone offers to sign in to the network, which opens the board's page. If it doesn't, open http://192.168.4.1/.
3. If the page opened in the phone's small sign-in window, open http://192.168.4.1/ in the real browser before uploading files. The sign-in window can't reliably pick files.

Keep these in mind:

• The access point is off after every restart, including the restart that finishes an update, unless the board can't join its network then. Press BOOT, or run wifi ap on, to bring it back. While the board is on your network, the Network page turns it on and off too.
• wifi ap says how long it has left (off in 4:25) when it came on by itself or from the button. wifi ap on keeps it on; wifi ap off turns it off now.
• The passphrase is random. The board makes it the first time and keeps it. wifi ap shows it, and wifi ap --pass <passphrase> changes it. To change the network's name, use wifi ap --ssid <name>.
• The station keeps working. If the board is also on your Wi-Fi, both addresses work at once. The access point then shares your network's channel.
• The board has no internet on its own access point, so it can't fetch releases itself. The Update page offers to fetch the release on your phone and send it on instead. That works if the phone still has mobile data.

A password¶

With no password, anyone on the same network can change, update or restart the board. On a network you share, set a password on the Settings page, or on the console:

web password <password>

Seeing what the board is doing stays open to everyone. Changes, downloading files, and the web settings now ask for the password. The web app asks for it once and keeps it until you close the tab. To remove it, run:

web password --clear

Even with no password set, a web page elsewhere can't drive the board from your browser. The board answers only requests that name it, and only in forms a browser won't send across sites, except for a few trusted sites. The HTTP API reference has the details.

Other sites and API tools¶

Pages on a few trusted sites may call the board's API from your browser: Swagger Editor, and this project's astromech.co and davidiansmith.ca, with their subdomains. That is what lets the HTTP API explorer try requests on a real board. Every other site is refused. To see or change the list, use the Settings page, or run:

web cors

The HTTP API reference covers adding and removing sites. Set a password before you add a site you don't control.

Turning it off¶

To stop the web server, run:

web off

The board remembers this across restarts. web on starts the server again.

Working on the web app¶

The pages are in web/ in the repository. They are plain JavaScript modules and CSS, with no build step. The firmware build gzips them into the image. To try a change without rebuilding and reflashing, serve them from disk and pass the API through to a real board:

python tools/web_dev.py holo-2db0.local
# then open http://localhost:8080/

A new page is one module in web/pages/, listed in web/app.js. The page appears when the board's /api/v1/info lists its feature.