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A Simple Factory BlinkUp Fixture

A Basic imp-based Device For Configuring Devices Under Test

A factory BlinkUp™ fixture allows you to cause Devices Under Test (DUTs) to load and run your factory firmware. It does this by sending to the DUT a factory enrollment token and, if required, factory WiFi credentials. This data is transmitted optically via the fixture’s LED.

  • If you are unfamiliar with the Electric Imp Connected Factory Process, please take a moment to read our brief overview, which includes a full glossary of the terminology you will encounter here.

At its most basic, a BlinkUp fixture is simply an imp and an LED. Adding a button allows an operator to trigger factory BlinkUp. This short guide shows how to use any imp breakout board, such as the imp004m Breakout Board, as a factory fixture. Fixtures can be constructed from any equivalent hardware based on an imp module, but you may need to change the pin settings in the function configureFactoryFixture() in the code listed below.


Connect your imp004m Breakout Board to the following circuit:

  • Connect the LED anode (long pin) to the imp004m Breakout Board’s pin A.
  • Connect the LED cathode (short pin) via the 220Ω resistor to GND.
  • Connect the switch between the imp004m Breakout Board’s pin P and GND.


1. Power The BlinkUp Fixture

Connect the BlinkUp fixture to power via Mini USB.

2. Add The BlinkUp Fixture To Your Electric Imp Account

Use the Electric Imp App to add the BlinkUp fixture to your Electric Imp account. For more information on this part of the process, please see this guide.

3. Assign Your Fixture To A Factory Test Device Group Or A Factory Device Group

If you are making use of impCentral’s factory test environment, Test Zone — this is the recommended procedure — then you will need to add the BlinkUp fixture to a Test Factory Device Group. You can learn how to do so here.

If you are going straight to production, you should instead follow the steps for a Factory Device Group, outlined here.

4. Develop Your Factory Firmware

The following code is ready to use with the circuit described above, but you will need to add hardware tests relevant to your own connected product in the appropriate section of the code, which should be pasted into impCentral’s code editor after selecting the Test Factory Device Group or Factory Device Group to which you assigned the BlinkUp fixture in Step 3, above.

You will also need to change the value of the SSID and PASSWORD constants to match the settings of your local (during testing) and factory (during production) WiFi network.

Sample Factory Firmware

5. Send Factory BlinkUp

Align the photosensor integrated into your DUT with the fixture’s LED and press the button to initiate the factory BlinkUp. The target device receives the BlinkUp data, then uses it to connect to the programmed WIFi network, and to download and run the same factory firmware that is running on the BlinkUp fixture.