Bringing state-of-the-art LED Lighting to Hobbyists
The Light Shield 7 is an Arduino and Maple compatible shield which adds several featuers useful for a variety of applications, but also specifically for use with the Light Brick 5 which it is designed to be integrated with.
Warning: If you choose to assemble your own light fixture, your warranty will be limited. The below plans are provided "as-is", and no warranty express or implied is offered for fixtures not constructed in entirety by saikoLED, LLC. If the components sold by saikoLED and assembled by customer are damaged due to improper assembly, the customer is responsible for the repairs.
If you require a warranty beyond our standard 14-day return policy for undamaged goods, please purchase a complete Saiko5 fixture, which is assembled entirely by our staff. We can not be responsible for damage caused to our products due to customer assembly whether done according to the below plans or not.
The design of the Light Shield 7 is loosely based on the WiShield from async_labs. All design files can be downloaded from our Downloads page. Design files for the Light Shield 7 are released under a Creative Commons license.
The Light Shield extends the WiShield by adding a high efficiency 7.5VDC switching voltage converter to allow the Arduino and Maple to be operated from a 24VDC supply as well as using the more up to date versions of the WiFi module including external antenna, as well as a 5-pin header with passthroughs for the 24VDC power supply and PWM pins from the Arduino/Maple. Last, it includes a barrel power input plug to allow for more robust connections and the use of UL approved external power supplies.
The onboard high efficiency switching regulator uses the LM2675-ADJ from National Semiconductor. This 7.5VDC supply is connected to the V+ pin on the Arduino/Maple board in order to provide power to the onboard 5V/3.3V regulator on the controller board. The 5VDC regulated voltage is then taken back onto the Light Shield and used to power a 3.3VDC low dropout linear regulator to power the Microchip MRF24WB0MB integrated WiFi Module. This module takes advantage of a u.fl connector and external FCC approved antenna combination to provide a way to easily communicate with the Arduino/Maple over WiFi even when the board is mounted inside of our metal boxes. Additionally, the Light Shield incorporates a fuse and protection diode to help protect against user error in connecting powering the board. For reference, the distances which the Arduino UNO power connector and USB connectors stick out of the supporting board are marked. The design is such that our power connector should stick out further than the Arduino UNO connector, and when used with our case the USB and Light Shield power connectors will be exposed while the Arduino power connector will be blocked to prevent confusion.
Next, a solder stencil is used to place a thin layer of unleaded solder paste on the boards. We found that reflow soldering was mandatory to achieve good reliability. Soldering by hand often resulted in overheating of pads, as well as poor solder joints for the WiFi module. For more information about how to do reflow soldering, see the Extreme Surface Mount Soldering Instructable. In our case, we placed solder paste using a solder stencil, placed our components, and then used a tabletop hot plate to simultaneously reflow all components.
After reflow, the through-hole components are soldered onto the board, with the final result looking like this:
Case integration is discussed in detail in the documentation for the Saiko5 light fixture.
The Light Shield 7 Digikey Bill of Materials can be downloaded here. This document can be uploaded at Digikey in order to easily get all of the components required for assembling a Light Shield 7 of your own. This Bill of Materials does not include parts ordered directly from Microchip -- the MRF24WB0MB and the associated antenna, the TRF1001.