Start-up and shut-down

Like any computer, MiRo needs a little time to startup, and a little time to shutdown safely. Please do not turn MiRo on and off in quick succession, therefore.

It is possible, if unlikely, to damage the software installation on MiRo's SD card by interrupting the boot or shutdown processes, so please always wait for each process to complete, as described below, before operating the switch again.
Please read all of this page carefully before powering your MiRo for the first time.

Connecting the battery

Your robot arrives with the battery pack installed but not connected. To connect it, you need to open the battery cover underneath the robot. You can also follow these instructions to change the battery pack, if you have more than one.

To change the batteries, first ensure that MiRo is turned off. Now turn MiRo upside-down and support it securely by resting the body shell (and only the body shell) on something soft—see image for one solution.

Now remove the single screw securing the battery cover, and remove the battery pack from the robot. Find the battery pack connector and the connector inside the battery case, and plug them together. Refit the battery pack and close the cover, securing with the screw.

Disconnection is the reverse of connection.


Charging may be hazardous if performed incorrectly—please ensure you have read all the safety information in the Owner's Guide before charging the battery.

To charge the installed battery pack, plug the charger cable into the socket underneath the robot, and into a power socket. The charging light will glow red if the battery is charging, and will switch to green once it is fully charged.

Alternatively, you can charge a battery pack "off robot", using the included adapter cable. This will be useful if you have two battery packs and wish to continue using the robot whilst the second battery pack is recharging.

Please ensure your MiRo is fully charged before first use; in future uses, you can charge or operate your MiRo in any way you need to, but please make sure to turn it off when the low battery alarm sounds.
Do not plug in the charger when the robot is turned on (any lights are illuminated) since this will cut the power to the robot. Shut the robot down first.

Battery low

If MiRo's batteries are getting low, you will hear something that sounds a bit like a satellite from the 1970s. This is MiRo's battery-low warning, and you should turn the robot off immediately and recharge the batteries before proceeding.

Do not ignore the low battery alarm—the NiMH batteries may be damaged if they are drained beyond this point.

Turn on

With a charged battery installed, turn on your MiRo at the switch underneath.

Do not turn on the power switch unless all lights are extinguished.

Turn off

Turn off MiRo at the switch underneath.

Do not turn off the power switch unless the blue power state light is lit steadily.

Embedded reset

The on-board computer does not commence a shutdown until the power switch has been OFF for three seconds (see above). Whilst the power switch is OFF, the embedded computers are powered down.

Thus, you can reset the robot's embedded systems, without shutting down the main computer, by moving the switch through the sequence ON→OFF→ON within three seconds. This technique can be used to clear a crashed firmware state if this occurs (if this occurs regularly, however, something is wrong).

Do not repeat this sequence within three seconds—if you do so, you will trigger "Emergency power off", described below, and de-power the main computer without warning.

Emergency power off

In an emergency, power can be withdrawn immediately by triggering the emergency power off function. Power will be withdrawn immediately at any time that the power switch is moved through the sequence OFF→ON→OFF within two seconds.

In normal operation, you will move the power switch OFF→ON to turn on the robot. The power circuit then enters the two second emergency power off window, which is indicated by both blue and red main LEDs flickering in unison. If the power switch is moved ON→OFF during this window, power is withdrawn immediately. After two seconds, the window has passed, the indicator LEDs and the power circuit return to their normal behaviour, and the system continues to start (on-board computer boots). From this point forward, to withdraw power immediately, you must perform the OFF→ON→OFF sequence, so it is this sequence that will usually be used in an emergency.

You are advised to practice the emergency power off sequence in advance of any emergency. In order to do this without risk of data corruption you have the option of first removing the SD card from the on-board computer. Triggering emergency power off will withdraw power from the on-board computer without warning which may lead to corruption of the SD card.

In an emergency, the power will usually be ON. Therefore, to withdraw power quickly, you will perform the sequence ON→OFF→ON→OFF (three switch operations) in quick succession.
Avoid triggering this behaviour in normal use since de-powering the main computer without warning can lead to data corruption. As indicated above, do not cycle the main power switch rapidly unless you intend either an embedded reset or an emergency power off.