User Manual

mini-UART(ttyS0) and restore UART0/ttyAMA0 over GPIO 14 and 15. You can

achieve this by adding “dtoverlay=pi3-miniuart-bt” to the “/boot/config.txt” file. You

will also need to add “core_freq=250” to the “/boot/config.txt” file to make sure

Bluetooth can work properly. Don’t forget to reboot to let the changes take effect.

3. Software does not run automatically after Raspberry Pi system is on

After installing the software, you will have “daemon.sh”, “syncTime.sh” and

“runScript.sh” scripts in the directory that has software installed. These scripts should

be executed automatically after the operating system is up.

If these scripts are not automatically executed for any reason, Witty Pi Mini will cut the

power of Raspberry Pi, without lighting up the white LED. In this case, the first

place to check is the “/etc/init.d/wittypi” file, and there is possibility that it contains

wrong paths to these scripts.

If you are running a special distribution of OS, make sure to check if the commands in

the “/etc/init.d/wittypi” file do exist in the system, or it will fail silently. For example,

Minibian doesn’t have “sudo” command.

4. Witty Pi Mini is unexpectedly woken up by shutdown alarm

This could happen, after you scheduled a shutdown in the future, and then Witty Pi

Mini lost power connection. Raspberry Pi is off ungracefully and later the power

connection is resume. If the shutdown alarm occurs when Raspberry Pi is still off, it

will wake it up, which is unexpected. The software will detect this situation and

shutdown your Raspberry Pi immediately, and you will see the white LED lights up

before the shutdown.

Next time when you turn on your Raspberry Pi, it will be normal again, and you can

find this message in the log, for previous shutdown:

Seems I was unexpectedly woken up by shutdown alarm, must go back to sleep...

Sometimes the same case can happen when you tap the button to turn on your

Raspberry Pi, if the shutdown alarm occurs during the time that no power supply was

connected.

You may ask, how comes the shutdown alarm could act like a startup alarm? This is

specific to Witty Pi 2 and Mini. Witty Pi 2 and Mini uses the same RTC chip (DS3231),

which is way better than the one used in on Witty Pi (DS1337). The downside

however, is the better RTC chip merges two alarm pins into one. Hence without

turning on your Raspberry Pi and check the RTC registers, there is no way to know if

the current alarm is a shutdown alarm or not.

5. GPIO-4 pin doesn’t reach a stable status in given time