Using rasp-ap to turn OFM into an access point

Summary

A common scenario are users who would like to connect their computer to the microscope over WiFi, but aren’t able to connect via a WiFi router (for example if their institution uses eduroam or there is no WiFi router). A couple of users have reported using rasp-ap and this week I set it up for a user who needed their setup configured like this. It was very easy to do and allows you to directly correct to your Raspberry Pi over WiFi, without an intermediary router. This is just a quick note to say that it works and so that others are able to replicate.

What rasp-ap does

Rasp-ap is an open source tool that turns a Raspberry Pi into an WiFi access point (AP). Once installed it also provides a web interface for changing the AP settings and more complex functionality.

How to install

I followed the quick start guide to installing the tool. I did not follow their steps to update the packages on the Raspberry Pi, in case it broke the microscope software. I followed their recommended settings during the installation wizard.

The default IP address for your Raspberry Pi will now be: 10.3.141.1

Connecting to the microscope

On your computer, connect the WiFi to the new AP of the Raspberry PI. By default the SSID is raspi-webgui and the password is ChangeMe.

Viewing/changing AP settings

You should probably change the default passwords (both for the AP admin web interface and the AP). Either on your computer or the microscope’s web browser, go to 10.3.141.1 and use the web interface to make the changes (default username: admin, password: secret).

Controlling the microscope

If you are using OpenFlexure Connect, mDNS should work as expected and your microscope will show up in ‘Nearby Devices’. Alternatively, the default IP address will be 10.3.141.1 and the port is 5000. If you are controlling via a web browser, you will therefore need to connect to 10.3.141.1:5000.