In this article we will be using a 3 character LED 7 segment display to display the RSSI of the WiFi chip on our Particle Photon module. This will help us determine the best possible place to mount our Particle Photon module and whether or not we should use an external antenna. The full application is available on Particle's WEB IDE(build.particle.io/build) so absolutely no programming is required. Video provides a full step by step tutorial on how to flash the firmware into your Particle photon module and get readings on the display.
What you need
- AS1115 3-Character Red LED 7-Segment Hexadecimal Display I²C Interface Decimal in Center of Board I²C Mini Module
- I²C Shield for Particle Photon
- Particle Photon Module
- Basic knowledge base for developing and programming with Particle Core/Photon modules.
Step 1: Setup Your Particle Photon and Account
Using I2C cable connect the 3 Character LED segment display Mini module to the I2C interface board and insert the Particle Photon module into the I2C Interface board. Then connect the Particle Photon module to a USB power source such as your computer.
Follow instructions here to setup your Particle Photon module for your WiFi network and associate it with your Particle Account so we can interface with it and flash in firmware.
Step 2: Flash Some Firmware
Click the Target Icon on the left and make sure your Particle Photon module is connected and selected here. Click on the Libraries Icon on the left, then search Community Libraries for SEGMENTDRIVER. Make sure the RSSI_Expample.ino tab is selected, then click the Use this Example button. Now click the devices icon on the left(looks like a target) and make sure your controller is online and selected. Now click the Flash button on the left(looks like a lightning bolt) to flash the firmware into your controller.
After the module is flashed with this firmware and reboots you should start seeing the RSSI displayed on the 3 character display. The lower the value the better the RSSI strength is.
The complete source for this firmware is available on our GitHub repo.
Step 3: Test and Control Your Board Through Mobicle.io
Go to Mobicle.io
Log in with your Particle credentials if prompted. Now select the controller from the device list you just flashed the RSSI firmware to. On this page you will see a variable displaying the module's current RSSI value along with 2 functions. Click the second function(SelectAnt). Here you can enter External or Internal as the argument to switch the Photon module's antenna. If you do not have an external antenna you will want to leave this set to internal which is the default but you can play around with switching to see the effects on your RSSI signal strength.