Thought I should share this…
I just stumbled upon ControlEverything - https://www.controleverything.com/products which has an awesome array of relays, controllers, sensors and more custom interfaced for several platforms including the Particle Photon! Really cool stuff… wish I’d thought of it!! 
Updated - They have relay interfaces for various platforms with an I2C controller on board, and a huge selection (albeit pricey) of I2C sensor modules that can be daisy-chained.
Wow, lots of high quality sensor breakout boards over there!
Thanks for sharing this 
I just purchased 2 different magnetic rotational position sensors from them which something I have not found available with ready to use i2c code so this helps me out tons.
@RWB I saw a kickstarter for stepper motors that used one of those rotational position sensors to sense the shaft position. they made a stepper servo with it.
@Hootie81 I’m happy to hear that they are using this type of sensor since it must be very accurate. and I was interested in that Kickstarter also but had no need for stepper motors so I passed.
I’m gonna go check out their design again to see where they placed the sensor compared to the central shaft.
Thanks for pointing this out. I’ve tried a few potentiometers but they are not as accurate as I need and they are overpriced.
they put a small magnet on the end of the stepper shaft and the sensor was directly over the magnet, directly in line with he center of rotation. because there is no load on the magnet it just sticks to the shaft and doesn’t move
I was in the same boat as you… no need for them at the time, and slightly too expensive.
@hootie81 My application has shafts coming out of both ends of the motor so I can’t do it the way they are so I’m intersted in how they work with the shaft being off center of the sensor. Their datasheet says this can be done so we will see. Should be interesting.
@RWB, @Hootie81, @MisterNetwork
I just wanted to chime in. I am an engineer/developer here at www.controleverything.com
On the subject of motor controllers we are currently designing an extensive line of motor control products including Linear Actuator controllers, Servo Motor Controllers, Stepper Motor controllers, and more. These are not concepts, we have in house working prototypes for all of them. I ran around to a few engineering benches and snapped some photos. Have a look here:
We’re just getting started!
We will release literally thousands of products for Particle based modules. We already have an extensive line of Electron Based controllers working in house ready for the Electron’s release.
Now, on the note of cost. I think it should be said that our products are designed and manufactured in the U.S. which is certainly not the cheapest route to manufacture products like these. That said we firmly believe that by manufacturing everything in house here in America we can ensure a top quality product.
Be sure to keep an eye on ControlEverything.com New products will be released frequently.
Controlling a servo or linear actuator with a rotary encoder on a particle device may appear to be easy. I attempted it a while ago and hit problems with interrupts from the encoder making the spark disconnect from the cloud.
Is there a library that works reliably with particle devices?
Impressive range of products but the price for a 16 bit ADC is more than what particle charge for a photon.
I appreciate the fact that they are produced in the USA and the quality is unquestionable but the prices are just too much, to succeed I think you would have to find a way to halve them. At least. I cannot imagine many Sparklers paying $145 for a 16 channel relay module.
I am fanatical about quality and reliability and appreciate that your products are both but there is a limit to what is affordable considering alternatives
We had a good long discussion this morning and have taken your recommendation into careful consideration. We have concluded that you are right. Perhaps these products are a bit expensive. In fact we have taken your recommendation literally and have cut the price on most of the products on our site in half as you suggested! I would also like to mention that even though we cut prices in half on many products Particle based devices will still come with a FREE Photon, so please be sure to also factor that in when re-evaluating the new prices on the site.
That said some products on our site are simply too low cost at this point to lower any further. Our Mini modules as an example are already priced $5 over component cost. This means that packaging, labor, design, and marketing all have to come out of the $5 markup so they simply cannot be lowered at this time. I believe if you compare our prices on those products to similar products you will see they are very reasonable. As demand for our products grow prices on them may lower due to higher volume. We will continue to adjust pricing on our products as time goes on.
This is our first venture into the Maker/Hobbiest market so we are still working to appeal to this wonderful group of people. We have sold control and monitoring devices to the Industrial/Commercial sector for 20 years but this is a whole new ballgame for us.
We sincerely appreciate your feedback and insight. We WILL listen to the demands of the customer base and will do everything we can to ensure that you are happy and excited to experiment, work, and play with our product.
I just looked the 16 Bit ADC: https://www.controleverything.com/content/Analog-Digital-Converters?sku=ADS1115_I2CADC the price on it is $17.95
A photon is 19.00 and is a completely different piece of hardware.
And the Adafruit version: https://www.adafruit.com/products/1085 is $14.95, and isn’t really the same product either since the control everything board includes screw terminals and pluggable I2C ports.
The I2C 16 bit adc was $19.50 last night. Read the response from the manu, they have immediately lowered their prices.
So a photon is not a 16 bit adc? Thanks for that! 
Thanks for the response, I was not expecting that. Great news that you have taken that approach and I wish you the best of luck breaking into the maker market. Your products are very appealing and I must admit I had not noticed that you supply a photon with some of the products, that makes a big difference.
The relay boards look perfect for home automation / security. Anybody fitting systems professionally will love them. For the maker market I would imagine that a relay board that could have a variety of modular I2C sensors plugged in and perhaps an oled or touchscreen display / sd card reader would be a hit.
@IOTrav Keep up the good work guys. Feel free to play with your pricing, your going to need to make more than $5 to stay in the game unless your selling tons.
A difficult period for any business, they can’t afford to make a loss but equally can’t afford to price their products out of the market. If I knew any more I would be a successful business man.
I, for one, would like to say, “Kudos!” to the ControlEverything folks for coming out with a great bunch of offerings to facilitate development of products and custom systems. I look forward to more offerings as I know you folks make quality products. The inclusion of libraries makes puts this within reach of anyone interested in Particle. I will be ordering soon. Thanks!
BTW, the price reduction is greatly appreciated as long as it doesn’t jeopardize the viability of the product from CE’s perspective.
Pretty impressive products, not that its too hard to multiply a 8channel board, but that you actually stock a 32channel relay board is awesome
@gjaman
If you just want to connect your Particle controller to our mini modules you might just want to get one of these I2C interface boards we offer which has the plug on it:
Also note that the cable for connecting the Mini modules is always included.
If this is not what you were looking for please let me know.
Thanks @IOTrav - I’m creating my own shield PCB for the photon/electron. I’d like to include an option on my PCB to connect to your mini modules, so I’m looking for the part number for the jack you use/recommend.
