Particle Photon

The Particle Photon is a welcomed update of the Core. It brings the same form-factor and pins, runs 50% faster, has 4 times more flash and 6 times more RAM, all that for half the cost.

The MCU remains a STM32 Cortex-M3, but is now a STM32F205 (previously, STM32F103) and runs at 120Mhz (80 MHz). More importantly, it features 1 MB of flash (128KB) and 128KB of SRAM (20KB). 

The boards has the same form-factor and pins, with 16 GPIOs, 8 of them analog, and the standard I²C, SPI, UART and JTAG ports.

For WiFi, the BCM43362 from Broadcom replaces the CC3000 SoC from Texas Instruments. The WiFi provides the standard WiFi 802.11 b/g/n and is FCC, CE and IC certified.

At USD19, the board is aggressively priced.
The package is minimalistic with the board only.

Configuring the board includes more steps than with the previous Core, based on the SmartConfig technology from Texas Instruments.

  • Use an iOS- or Android-based smartphone, 
  • Download the Particle app and launch it,
  • Select Photon,
  • Open the Settings of the smartphone and select the WiFi network called Photon-XXXX.
  • Return to the app.
  • The app finds the Spark Core and configures it. 

All the steps are described in this procedure.
Once the board is configured and connected, the same app launches Tinker, a remote-control for the board. 

I've selected the GPIO D7 which corresponds to the blue LED and defined it as digitalWrite (left). 

Touching the D7 button on the smartphone turns the blue LED on and off (right).

Because the commands go through Internet, the board and the phone can be located anywhere in the world, provided both have access to internet.

Hardware

The main board includes one RGB LED for status, one blue LED connected to pin D7 and two buttons for configuration.

The Photon pins map is identical to the Core pins map.

The RGB LED provides the status of the board based on its colours and speed of the blinking. The two buttons, RESET and MODE, allow to reconfigure the board, from soft reset to hard reset and factory reset.

As for the Core, it is easy to get lost with so many colours and speeds combinations, hence the need for the handy help sheet I designed for the Core.

Software

The major difficulty with the Internet of Things deals with the multiple environments to deal with when developing a project:
  • a first environment for the board, rather easy thanks to the Processing / Wiring / Arduino combination,
  • a second environment for the remote, either a website or an iOS- and Android-based  smartphone, with a much more complex set of APIs,
  • and finally a third step called integration to make sure the board and the smartphone work together as expected.

Spark provides three sets of tools reviewed at the Particle Tools page: 
  • an online IDE, 
  • an offline Particle Dev IDE based on Atom, 
  • and offline command line tools.

Services

Recently, Particle has launched a new service called Dashboard, which displays data published by the Core and Photon boards. 

The dashboard shown on the right was populated using one single simple line of code.
Although still in beta and pretty limited, the Dashboard is very promising. Closely integrated in the Particle SDK, sending data can't be easier! Read the full review.

Conclusion

The Particle Photon is a much welcomed update of the Core, with a powerful MCU but at half the price. Particle still offers the unique package of hardware, software and services. 

I've found the Particle less easy to configure than the Core (the Core relies on the SmartConfig technology from Texas Instruments).

For now, the biggest challenge is the lack of valid alternative to the cloud IDE. The command line tools aren't reliable, making serious development just impossible. Maybe Particle should focus on delivering the tool-chain anyone could use with any standard IDE, instead of exploring Atom. 

At USD19, the Particle provides a great introduction to the Internet of Things with an end-to-end solution and projects running in in a couple of minutes!

Pros

  • Powerful 32-bit ARM Cortex M3 MCU
  • Good out-of-the-box configuration and demo for iOS and Android devices
  • Online IDE for virtually any browser

Cons

  • Off-line tools still in development
  • Too many blinking colours for the LED

Wrap-Up

  • Very compact board with powerful MCU
  • Perfect introduction to the Internet of Things with end-to-end solution
  • Great value
  • No valid alternative to the cloud IDE
  • Not supported by embedXcode

Links
Support for this platform by embedXcode, embedded computing on Xcode, in planned.