This article describes how to troubleshoot Red Panda MIDI devices on Mac OS, but also applies to MIDI devices in general. Our pedals can connect to a Mac using a USB mini B cable or via 1/4" TRS MIDI.
Make sure your USB mini B cable is designed for data. Some "charge only" USB cables do not have wires for data transmission, even though the pins are present on the connector.
For general MIDI troubleshooting, MIDI Monitor by SNOIZE is a very useful tool to log MIDI messages sent between devices and apps.
If the device does not show up in the web editor or Mac OS apps, follow the steps below.
USB MIDI
Plug in power and connect the pedal to your Mac using a USB mini B cable.
If the pedal shows up as an external drive, that means it was started in USB Mass Storage mode for firmware updates. Plug in the pedal normally (without holding down either footswitch) to use MIDI.
If you have Google Chrome installed, open the web editor for your pedal. The URL for the Particle 2 editor is:
https://www.redpandalab.com/content/apps/particle-editor/index.html
Note that the editor URL must start with https (not http), so that Chrome has permission to access your MIDI devices.
The first time you connect, Chrome will ask you to allow www.redpandalab.com to use your MIDI devices:
Click Allow. If you do not see that alert, make sure your security settings are not blocking it.
You should see a small MIDI keyboard icon in the address bar: 
If the icon has a red X like this: 
you can click the icon and select Always allow https://www.redpandalab.com to have full control of MIDI devices
The editor should reflect the current pedal knob settings and say "Status: Connected"
Go to the Help tab and click the Show MIDI Devices button. It should list your pedal under MIDI Inputs and MIDI Outputs. Both should say "(open)".
The editor prints some information to the JavaScript console on startup. You can open the JavaScript console by typing Command+Option+J or selecting View > Developer > JavaScript Console (if you have DevTools set up). Here, it found my Particle connected:
The Help tab of the editor also has a Log to JavaScript Console option, but that is not needed at this point.
Audio MIDI Setup is included with Mac OS (Applications / Utilities / Audio MIDI Setup). Open the MIDI Studio window (Window > MIDI Studio).
Your pedal should show up, along with all of your other MIDI devices.
If the pedal is grayed out, that means it is not currently connected:
To dig deeper, choose About This Mac from the Apple menu, click More Info..., then and click on System Report... at the bottom of the screen.
Select Hardware > USB in the left pane, then scroll through the USB Device Tree until you find your pedal. It should appear like this:
If the pedal does not appear in the USB Device Tree, check all of the USB cables and hubs between the pedal and your Mac. Try a different USB mini B cable. Some "charge only" USB cables do not have wires for data transmission, even though the pins are present on the connector. Data cables should have the USB trident symbol on their connector.
If the pedal shows up as a storage device, i.e., with "Bootloader" in its name or you see the drive in the Finder, then it was powered on in firmware update mode. Start it up in normal mode to use it as a MIDI device.
Additional USB troubleshooting
Our pedals are self-powered and will use slightly more energy when connected to a USB host. If your power supply is on the borderline, the pedal may work fine in normal use but not be recognized by the computer. Refer to your pedal's documentation for specific power requirements, but typically you will need a regulated 9V center negative power outlet that can deliver at least 250 mA (more info on power in troubleshooting power supply problems).
If you are still experiencing problems, please contact us and let us know what you see at each of the steps above.
TRS MIDI
When TRS MIDI is used, the USB MIDI device that Mac OS communicates with will be a MIDI interface or MIDI controller. You will need to create a MIDI configuration using Audio MIDI Setup to make the pedal appear as a device in Mac OS apps. In simple cases, you can select the MIDI interface in Mac OS and configure it (if necessary) to route messages to the pedal.