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BlinkUp Guidance That Customers Should Provide To End-users

Essential Support Material For Your Connected Product

Connected products based on the Electric Imp Platform will employ Electric Imp’s BlinkUp™ technology to activate new end-user devices and possible, depending upon the type of imp embedded in your product, local network access credentialsd. The app may also be used subsequently to re-configure those devices for new networks, or if the end-user changes their network settings: for example, if they purchase a new wireless router or update their network password.

As an Electric Imp Customer, you will therefore need to provide your end-users with a mobile app which they will use to perform BlinkUp. You may choose to provide BlinkUp optically — the activation data and any network information is transmitted by flashing the mobile device’s screen — or wirelessly via Bluetooth LE (currently available to imp004m-based products only). Cellular or Ethernet-only may not require a BlinkUp-enabled app at all, if you choose to activate devices in the factory.

It is highly recommended that, in addition to your app, you also provide clear guidance to help your end-users perform BlinkUp successfully and safely, and to solve any problems they may encounter. The vast majority of issues that an end-user is likely to experience during device activation can be prevented by actively guiding the end-user through the activation process to ensure that they obtain the required network information, if any, and enter it into your app correctly; that they check their network is compatible with the imp in your product; and that align their mobile phone or tablet screen with your product’s BlinkUp photosensor correctly.

This guidance can be included in the app itself as part of the account creation and product setup flow, provided as separate instructions on your website or in the collateral included in your product package, or — ideally — all of these.

This guide will help you understand what information you should include within this material, and in what order.

What Guidance You Should Provide To Your End-Users

Your BlinkUp documentation — whether in-app, on your website, in printed instructions, or all of these — will need to include the following:

Before BlinkUp

  • Specify all the information the end-user will need to collect before device activation:
    • The local WiFi network name, ie. its SSID.
    • The local WiFi network’s password.
      Note Devices that connect solely via Ethernet or Cellular will not need this information.
  • Indicate the WiFi compatibility of your product:
    • All imps can access 2.4GHz WiFi networks, but only the imp005 can connect to 5GHz WiFi networks.
    • No imp can connect to a WiFi network that presents a web page for network access login.
    • No imp can connect to an enterprise WiFi network that uses 802.1x.
      Note Devices that connect solely via Ethernet or Cellular will not need this information.
  • Help end-users successfully perform BlinkUp:
    • Clearly indicate where the product’s photosensor is located.
    • Clearly show how best to position the phone or tablet to ensure maximum BlinkUp signal.
    • Warn users not to do BlinkUp in bright lighting conditions, eg. outdoors.
    • Warn users not to do BlinkUp in unusual lighting conditions, eg. strobing lights.
  • Help end-users perform BlinkUp safely:
    • Provide a highly-visible warning about exposure to flashing lights.
    • Ensure that end-users do not need to look at the device and phone during BlinkUp.

After BlinkUp

  • If the device failed to connect, provide BlinkUp troubleshooting guidance:
    • Help end-users identify LED status color patterns.
    • Suggest solutions based on the pattern seen.

Let's look all of these areas in more detail.

Gathering Required Information

If your product is expected to connect to a WiFi network (this will be case for most products, and for all products based on the imp003 or imp004m), your end-users should be prompted to enter the following information into your mobile app:

  • The network’s name (SSID)
    • Note that this may be hidden, ie. not visible to the phone or tablet, so the user will need the option to key in the SSID as well as select from a list of networks visible to the app.
    • This can be pre-populated by reading the name of the WiFi network to which the mobile device is connected — but see the compatibility notes below.
  • The network’s password
    • Always give users the option to view the password’s characters as they enter them — this alone can eliminate many connectivity failures.
    • The imp supports WEP, WPA and WPA 2 security modes and can detect which is in use, so there is no need to ask the end-user for this information
  • Optionally, a WPS code
    • Note that this facility is not available to imp005-based devices (this module does not support WPS).

In addition, you should inform your end-users that they must ensure their WiFi network is compatible with your connected product’s imp:

  • Make sure they are connecting to a compatible network:
    • 2.4GHz 802.11b, 802.11g and 802.11n for imp003-, imp004m- or imp005-based products
    • 5GHz 802.11a, 802.11n for imp005-based products only.
    • Users with 802.11ac-branded routers and access points will have access to the standards listed above.
    • Devices intended for use in the US are permitted to use only certain WiFi channels, eg. 2.4GHZ 1-11. In other countries, your end-users may attempt to connect devices to networks operating on channels 12 and 13; this will fail if your device does not support these channels. Bear in mind that many routers auto-select channels by default.
    • Firewalls are generally only an issue for end-users connecting devices within an enterprise environment. Every imp will fall back to ports commonly kept open for general Internet traffic, but you should warn users to make sure outbound ports 31314, 993 or 443, and outbound port 80 are open. Imps use TCP only, not UDP, and do not require incoming ports to be open.
  • Make sure they do not connect to a router which uses a webpage for network access login, eg. a public hotspot.

Note This section can be ignored if you are offering an Ethernet-only product.

Health and Safety Guidance

BlinkUp transmits data by causing the mobile device’s screen to flash rapidly. Some of your end-users are susceptible to such strobing light because they are affected by medical conditions such as epilepsy. Your app and documentation must therefore make it very clear to all end-users that they should not look at the phone screen during BlinkUp. For example:


Always run BlinkUp with the screen facing away from you and towards the device being configured,
especially if you suffer from a medical condition that makes you susceptible to strobing light.

This warning should be presented before BlinkUp commences.

Some end-users may have visual or auditory disabilities; to assist such end-users through the BlinkUp process, you should incorporate visual, auditory and haptic indicators in your app to inform end-users that the BlinkUp process is about to begin and again when it has completed. This is especially helpful for end-users who may also be susceptible to flashing lights.

For example, the Electric Imp mobile app provides a three-second countdown before BlinkUp during which each second is signalled both with prominent visual cue and with an distinct audio tone. Once BlinkUp is complete, the app signals this with a further audio tone and by causing the host device to vibrate.

Physical BlinkUp

Other than password or SSID mismatches, and WiFi compatibility issues, physical device alignment is the cause of most other failed device activations. To avoid this, use clear diagrams and/or photographs to show the exact location of your product’s BlinkUp photosensor and to show how the end-user should position their mobile device relative to it — as close as possible, with the screen parallel to and facing the sensor window. For example:

End-users should also be encouraged to keep the mobile device is still as possible, and they should be instructed to avoid very bright ambient light (eg. outdoors) and flashing ambient light.

Note The BlinkUp status LED will be turned off by the product’s imp when it detects a BlinkUp signal. It can therefore be useful to position the status LED window where it will not be covered by the mobile device during BlinkUp. This allows the end-user to verify that the imp-enabled device has recognized that BlinkUp is taking place. If the product then fails to connect, you can be sure the problem relates to networking (password/SSID mismatch, or WiFi compatibility). Positioning the LED this way is also handy when you are tuning your product’s BlinkUp circuit and its housing.

After BlinkUp

Your product’s BlinkUp status LED will shows end-users the progress of the device’s attempt to connect and activate, and your app should show them what to expect: a series of red and orange flashes followed by slow green pulses. This can be presented in various ways, including animation, video or static images. For example:

In addition, it can be useful to warn users that after activation, the device may download an impOS update if one is available. This will cause the LED to go solid green (no flashing) while the update is downloaded and installed. This is normal behavior and no cause for concern, and the device will reconnect, ie. show the slow green flash, after installation is complete.

If the LED remains flashing orange, then your product was not configured — the end-user should attempt BlinkUp again, this time making sure they position the phone correctly under sensible lighting conditions.

If the LED remains flashing red, then your product is unable to connect in order to activate — the end-user should attempt BlinkUp again, this time making sure they have entered the network name and password correctly, and that the network is compatible with the product’s imp.