pi_power - power management for portable Raspberry Pi projects

I have been working on a portable Raspberry Pi project for a while - still not there yet but I've completed one important piece.

It's portable so it obviously has a battery. The Pi takes quite a bit of power so it needed to be rechargeable and include a charger. Adafruit make a great device called the PowerBoost 1000C which takes care of the core charging and power supply functions. But I really wanted my project to work like my phone does:

To power it up from a cold state, press a button for a few seconds

To power it off, press the same button for a few seconds

Indicate how much power remains in the battery

Provide an alert when that is running really low

Shut down safely without any data corruption if the battery does run out

To recharge the battery, just plug in a cable from a USB charger

I couldn't find anything that provided all the functionality I wanted - so I built my own

pi_power consists of fairly straightforward circuitry that links the PowerBoost to the Pi in conjunction with two python scripts that run in the background and monitor the battery voltage.

If you are building a portable RasPi project then you might want to take a look

https://github.com/craic/pi_power

Raspberry Pi - strange icon in top right of screen

I have been working with a mobile Raspberry Pi project powered by a LiPo battery and a Powerboost 1000c charger from Adafruit to handle battery charging.

Several times I have seen a small square icon in the top right of the attached small HDMI screen that has a rainbow of colors. I had absolutely no idea where this came from or what it represented.

But now I do... https://www.raspberrypi.org/forums/viewtopic.php?t=82373

The B+ (and presumably later models) has an under-voltage trigger that shows itself as this 'rainbow' square in the top right of the display when the supply voltage drops below 4.65V.

In addition, an over-temperature trigger displays a solid red square in the same location if the temperature goes above 85deg C.

You can disable the warnings in config.txt - see the link for details

I'm glad that the system has these triggers but I don't think the display of a red/rainbow square is a good way to inform the user.

Private Wi-Fi Networks, Raspberry Pi and Mac OS X Mavericks

I ran into two problems connecting to my Wi-Fi network recently - both turned out to be the result of the network being private and not broadcasting its SSID (Service Set Identifier) - the 'name' of the network.

My network runs on an Apple Time Capsule using WPA2 encryption. It has worked fine with other machines - MacBook, Win PC, Chromebook, iPhones...


#1 Getting W-Fi running on a Raspberry Pi

I was not able to get Wi-Fi running on a Raspberry Pi linux machine, despite trying a range of configurations that I found on the web.

When I changed the network to make its SSID public then it connected just fine with the basic configuration.

#2 Setting up a new MacBook Pro

When you start up a brand new Mac it walks you through several setup steps, including connecting to a network. The new MacBook Pro only has Wi-Fi so connecting to the network is essential. But in my case it did not see the private network and so I was unable to get through the regular setup.

The work around was to skip those steps until I got to the regular desktop. Then going into Preferences and Network and configuring the network manually I was able to get in.

I think that if the SSID were broadcast then I would not have had any problems.


The reason to keep an SSID private is to make it more difficult for someone to break into your network. If they don't know the network exists then they won't try and break in. In reality, however, it not that simple. A serious hacker will still be able to detect packets on all networks in the area including the 'hidden' ones and then attempt to break in. So a private network is a good idea but it does not offer great protection.