Raspberry Pi Setup¶

Installation¶

Our instructions assume a Mac is being used.

Put the micro-SD (e.g.: cheap one on Amazon) that will hold the Rasp Pi image into an SD Card reader (on our Mac).
Download a Rasp Pi image. Note: We use the Lite image.
Run Etcher to copy the image onto the SD Card.
Open a terminal window and cd into the boot drive. For us this was cd /Volumes/boot.
Add “SSH” file to the root of the image. We do this by opening a terminal on the boot partition and typing $touch ssh
Create the wpa_supplicant.conf file:
```
$touch wpa_supplicant.conf
```

Copy the contents into the file:

$ nano wpa_supplicant.conf

country=US
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1

network={
    ssid="YOURSSID"
    psk="YOURPWD"
}

Note: Multiple wifi networks can be set up by following this example:

network={
    ssid="SchoolNetworkSSID"
    psk="passwordSchool"
    id_str="school"
}

network={
    ssid="HomeNetworkSSID"
    psk="passwordHome"
    id_str="home"
}

Changing the ssid and psk to match your network.

‘safely’ remove the SD-card.
Put the SD-card into the Rasp-Pi’s micro-SD port
Power up the Rasp Pi. Hopefully wireless is working!

We need to know the IP address of the Raspberry Pi on the wireless lan.

Figure out the wireless lan’s subnet:
```
ifconfig | grep inet
```

We find two 192… IP addresses:

inet 192.168.2.1 netmask 0xffffff00 broadcast 192.168.2.255
inet 192.168.86.20 netmask 0xffffff00 broadcast 192.168.86.255

The 192.168.2.* is the router’s network. This means the Raspberry Pi is on 192.168.86.*

Open up Angry IP (or another IP scanning app) and scan for IP addresses in the 192.168.86.* network. We found a new Raspberry Pi with the name raspberrypi.lan.
start an ssh session by opening a Terminal window, e.g.:
```
ssh pi@192.168.86.33
```

The initial password is raspberry .

Optional - but a GOOD IDEA is to change the default password using the:

$ passwd

command.

Update the Raspberry Pi’s OS:

sudo apt-get update
sudo apt-get upgrade
sudo reboot

Change the timezone. The date/time is set to GMT. We find it easier to work with dates in our local timezone. We used the directions provided by MBTechWork’s website.

Install mongodb:

sudo apt install mongodb
sudo systemctl enable mongodb

To check if the mongodb service is running:

systemctl status mongodb

We use Python’s virtual envioronment package:
```
sudo apt-get install python3-venv
```
We also install git:
```
sudo apt-get install git
```
Pandas installation was failing with the message:
```
Importing the numpy c-extensions failed.
```

To fix this:

sudo apt-get install python-dev libatlas-base-dev

That’s it for installing Raspberry Pi to communicate with the electricity monitor.

Other Stuff¶

Here’s some stuff that may or may not be useful.

Mount Drive¶

There are times when it is useful to access the Rasp Pi drive from the finder. To do this, we use SSHFS. - Install SSHFS. - Create a directory to mount to (e.g.: /users/auser/mount). - Open a terminal window and run (replace the raspPi IP address and mount point) e.g.:

sshfs pi@192.168.86.209: /users/auser/mount

The /home/pi directory of the RaspPi will be mounted as a drive in Finder.

Unmount¶

Sometimes the mount gets into a state of limbo. When that happens, this command seems to work:

sudo umount -f /users/mj/mount

No SSH, Won’t connect to wifi¶

This happened to us (grrrrrrr)… We had files we wanted to access but could not longer connect to the Rasp Pi over ssh….

We got our Rasp Pi in such a tizzy that we couldn’t figure the magic incantations to make it all better (a warning to us explorers who blindly trust a blog post about ufw. Luckily we were able to mount the drive on our Mac following these directions:

sudo mkdir /Volumes/rpi
brew cask install osxfuse
brew install ext4fuse
diskutil list

Now here is where it gets a tad tricky figuring out what partition ID we want to mount.:

/dev/disk3 (internal, physical):
#:                       TYPE NAME                    SIZE       IDENTIFIER
0:     FDisk_partition_scheme                        *63.9 GB    disk3
1:             Windows_FAT_32 boot                    268.4 MB   disk3s1
2:                      Linux                         63.6 GB    disk3s2

Our SD Card reader is internal. We want the Linux partition. So the ID is disk3s2:

sudo ext4fuse /dev/disk3s2 /Volumes/rpi -o allow_other

now we can access the file from Terminal.

At least we can get the files off the SD card!