From ca1e2c963e98b309ad3b65c5fc538f052ea5fd64 Mon Sep 17 00:00:00 2001
From: Josh Beckwith <1918844+positlabs@users.noreply.github.com>
Date: Sun, 7 Jul 2019 13:00:22 -0400
Subject: [PATCH] Add note about LIBUSB_ERROR_IO

---
 README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 5681e2e..80bdfbc 100644
--- a/README.md
+++ b/README.md
@@ -125,7 +125,7 @@ You can find the full list of specs at the USB Implmentors Forum. Look for a doc
 
 To debug the USB descriptors, open chrome://usb-internals in Chrome
 
-On Raspberry Pi, you need to run node as root in order to access USB devices. Alternatively, you can add a udev rule to grant access to the default user, as described in [this AskUbuntu answer](https://askubuntu.com/questions/978552/how-do-i-make-libusb-work-as-non-root).
+On Raspberry Pi, you need to run node as root in order to access USB devices. If you don't have access, you'll get a `LIBUSB_ERROR_IO` error on initialization. Alternatively, you can add a udev rule to grant access to the default user, as described in [this AskUbuntu answer](https://askubuntu.com/questions/978552/how-do-i-make-libusb-work-as-non-root).
 
 Pull requests and testers welcome!