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BlinkUp Troubleshooting Guide

If you are having trouble configuring your imp-enabled device with BlinkUp™, please follow the instructions in this guide.


Some devices signal issues on their LED at start-up. Please see Device-Specific Codes if you are seeing unexpected patterns before BlinkUp.

Performing BlinkUp

When configuring your device with BlinkUp, please ensure the following:

  • The imp-enabled device is powered on.
  • The imp-enabled device’s status LED is blinking. If it is not, you need to restart the device.
  • You have the correct BlinkUp app for the device.
  • You have obtained and entered the correct network SSID and password. Make sure your mobile OS and/or third-party add-ons have not auto-capitalized the first letter of your password — passwords and SSIDs are case-sensitive.
  • You are not trying to connect to a public hotspot or other wireless network that requires you to sign in via a web page — this access mode is not supported by any imp.
  • You are not trying to connect to a network that the imp in the device cannot reach.
    For example, an imp001 can’t connect to a 5GHz network, though an imp005 can.
  • The screen of your mobile device is as close as possible to the imp-enabled device’s BlinkUp sensor for the entire time the screen is flashing.
  • Your mobile and imp-enabled devices are kept as stationary as possible during BlinkUp.

Common BlinkUp Problems and Their Solutions

Please refer to the imp LED color codes, below

  • Stuck at ‘No WiFi settings’ (long amber flash)
  • Stuck at ‘Searching for WiFi network’ (long red flash followed by two short red flashes)
    • Check that your network name (SSID) has been entered correctly, making sure that you observe capitalization, special characters etc.. imp001-, imp002- and imp003-based devices will only join 2.4GHz WiFi networks. imp005-based devices can connect to both 2.4GHz and 5GHz WiFi networks.
  • Stuck at ‘Joining WiFi network’ (long red flash followed by three short red flashes)
    • Check that your network password has been entered correctly, making sure that you observe capitalization, special characters etc.
  • Stuck at ‘Getting IP address’ (alternating short red and amber flashes)
    • Ensure that DHCP is active on your router and has sufficient IP addresses for all of your devices, including your imp-enabled device. Also check that ‘MAC address filtering’ isn’t enabled, or if it is that it isn’t denying the imp access to the network.
  • Stuck at ‘Resolving server name’ (alternating short amber and red flashes)
    • Check the DNS settings on your router. Devices still running early versions of impOS™ may be confused by the ‘DNS Relay’ mode on some routers — try disabling this mode.
  • Stuck at ‘Connecting to server’ (alternating long amber and short red flashes)
    • Check the firewall settings on your router. The imp needs to make a TCP connection to port 31314; ensure this is not blocked. Only TCP 31314 needs to be open; UDP 31314 can remain closed.
  • Connects to server (green flash), then flashes red, then repeats?
    • This is usually the symptom of a runtime error in the device’s Squirrel code. For developer devices, an error message will be logged in impCentral™ when this happens.
  • The LED stays red or flashes red very rapidly?
    • This indicates a power supply issue. The device boots, turns the red LED on and then tries to activate WiFi. However, the WiFi power draw reduces the on-board imp’s operating voltage below tolerance and the imp resets. This continues ad infinitem. Check the power supply feeding your device.

BlinkUp Status Codes

The following table should help you identify the color patterns your device’s BlinkUp status LED may signal. The smallest marked time unit is one quarter of a second. If you are having trouble identifying the pattern, you can click on the play icon to view an animation of that flash pattern.

No WiFi settings, plan ID
or enrollment token

(Release 33 onwards)
Video play icon BlinkUp: No WiFi
No WiFi settings/
imp005 waiting for Ethernet

(Release 33 onwards)
Video play icon BlinkUp - waiting for Ethernet / no WiFi
No WiFi settings
(Prior to release 33)
Video play icon BlinkUp: No WiFi
BlinkUp successful
(Release 32 onwards)
Video play icon BlinkUp: Success (R32 and up) for three seconds
BlinkUp successful
(Prior to release 32)
Video play icon BlinkUp: success (R30 and under)
BlinkUp unsuccessful
(Prior to release 32)
Video play icon BlinkUp: unsuccessful
WPS in Progress (press
WPS button on router)
Video play icon BlinkUp: WPS in progress
Searching for WiFi network Video play icon BlinkUp: searching for WiFi
Joining WiFi network Video play icon BlinkUp: joining WiFi
Getting IP address Video play icon BlinkUp: getting IP
Resolving server name Video play icon BlinkUp: resolving server name
Connecting to server Video play icon BlinkUp: connecting to server
Connected to server Video play icon BlinkUp: connected to server
Proxy Address/Port Incorrect
(Release 33 onwards)
Video play icon BlinkUp: proxy address or port rejected
Proxy access credentials rejected
(Release 33 onwards)
Video play icon BlinkUp: proxy credentials rejected
Device lost connection Video play icon BlinkUp: lost connection
Device Deliberately Offline Video play icon BlinkUp: device deliberately offline
(Release 32 onwards)
Video play icon BlinkUp: updating impOS continuous for duration of upgrade
Downloading update
(prior to Release 32)
Video play icon BlinkUp: update downloading
Installing update
(prior to Release 32)
Video play icon BlinkUp: updating impOS continuous for duration of install
Normal operation Video play icon BlinkUp: normal operation continuous

A solid red or rapidly flashing red LED indicates a power supply issue.

Device-Specific Codes

The imp003 and imp005 have a number of unique LED codes which signal problems with the SPI flash unit that must be connected to the module. These are displayed when these modules start up and do not relate to BlinkUp. If you are encountering unexpected LED light sequences on an imp003- or imp005-based device, please see the respective Hardware Design Guide:

Once it has been enrolled, an imp005-based device will show the ‘Waiting on Ethernet’ pattern while it is attempting to connect by Ethernet. This is identical to the ‘No WiFi Settings’ pattern indicated by other imps. The imp005 does not support WPS, so will never show the ‘WPS in Progress’ pattern.

Choose the Correct BlinkUp App

All imp-enabled devices — which includes your development hardware, factory BlinkUp fixtures and production devices — are configured using BlinkUp. However, not all of these devices are configured using the same BlinkUp implementation. The following table shows the different ways different devices are sent the BlinkUp configuration signal.

BlinkUp... Use... Appears in impCentral
‘My Devices’ List?
Device Type
...Your prototype hardware ...The Electric Imp app Yes Developer
...Factory BlinkUp fixture ...The Electric Imp app Yes Developer
...Your product in assembly ...Factory BlinkUp fixture No Production
...Your product in use ...Your BlinkUp app No Production

Note This table covers devices that will connect to Electric Imp’s Public impCloud™. Devices which will connect to a Private impCloud are configured by the customer’s own BlinkUp app in either development or production mode, as appropriate. Only production devices on the assembly line are configured using another means: a factory BlinkUp fixture.

Android Phones and Tablets

Recent versions of impOS contain many major improvements to BlinkUp on Android devices. Older imps running earlier versions of impOS will not benefit from these improvements until they are updated, a process which can’t take place until your device’s imp has first connected to the Internet after being configured by BlinkUp. If you are having problems configuring a device with an Android phone or tablet, the following may help you get the device to the stage where it can update itself. Ensure:

  • Screen brightness is not set to Auto
  • Screen brightness is at maximum
  • If you have a Samsung phone, Power Saving is off:
    • From the home screen, swipe from top to bottom to open the Quick Settings menu
    • Scroll across the Quick Settings menu until you find ‘Power Saving’
    • If Power Saving is enabled, disable it

These adjustments shouldn’t be necessary when the imp-based device has updated to the latest version of impOS, which will take place when the device first connects successfully. If you are still having problems connecting a device for the first time, try configuring it with an iOS device if you can. This will allow the device update, making future, Android-mediated BlinkUps successful.

For a list of Android devices confirmed by Electric Imp and its customers to work well with BlinkUp, see the BlinkUp Mobile Device Compatibility Guide. Many other devices also work will with BlinkUp but have yet not been formally tested. If your device is not listed, following the advice above will ensure your device is prepared for BlinkUp.


For detailed information on imps’ wireless and wired networking requirements, and on issues which may arise during an imp’s attempt to connect to a network, see ‘Network Requirements for imp-enabled Devices’.

Note As of impOS release 36, the imp005 does not yet support Wireless configuration using WiFi Protected Setup (WPS).


A device’s embedded imp is designed to be driven by a 3.3V DC power supply, commonly derived from a 5V USB feed or from connected batteries. The imp’s operational power range is 1.8-3.6V, but WiFi requires at least 2.5V. If the supply voltage drops below 2.5V, the imp will continue to process Squirrel code (provided the supply is 1.8V or greater) but WiFi will be disabled.

A common source of BlinkUp configuration and connection problems is insufficient power to maintain WiFi while the device makes its initial connection to the Electric Imp impCloud. It is during this process that the device is authorized to connect to the server now and in the future.

Insufficient power at this point can be caused by low batteries, a power supply with insufficient current capacity, or a supply with insufficient voltage. If the power supply can’t support the imp, the imp will attempt to connect, run out of power, reset itself and repeat. This can appear as a fast red blink pattern as the imp quickly reboots over and over again. This LED pattern is a sure message to check your device’s power feed.

BlinkUp Progress

The Electric Imp  mobile app shows the device’s progress from configuration to connection is presented on the screen of the phone or tablet you are using to set up the device. When the process completes successfully, the app displays the device’s ID and the URL of its agent. The URL can be shared by SMS or email.