1-Wire® Grid-EYE® Sensor w/Arduino-Compatible PCB - Review

Table of contents

RoadTest: 1-Wire® Grid-EYE® Sensor w/Arduino-Compatible PCB

Author: adsicks

Creation date:

Evaluation Type: Evaluation Boards

Did you receive all parts the manufacturer stated would be included in the package?: True

What other parts do you consider comparable to this product?: null

What were the biggest problems encountered?: Specifications for the reference board and pinouts not provided.

Detailed Review:

Overview

 

 

I am honored that Element 14 and Maxim Integrated chose me to Road Test these boards. This challenge was as much of a RoadTest for me and my skills as it was for the package they sent me. I have learned much about this product and myself as a result and I am truly grateful. In spite of the kinks this RoadTest was enjoyable as well as challenging.

The main goal of this review was to determine if the Grid-EYE sensor could work through panes of glass and if so how well. Unfortunately I found the Grid-EYE to be completely useless through glass. That being said, it isn’t a useless product by any means. And having a Grid-EYE on a 1-Wire interface is probably the most fun way I can think of to learn how the 1-Wire protocol works. I think Maxim has the right idea using Panasonic’s Grid-EYE as the sensor in combination with bringing 1-Wire switches and controllers to the Arduino platform.

 

Unboxing

 

My full unboxing report is here.

 

To be brief – during the unboxing I had problems getting the firmware going. It seems my Arduino IDE kept updating the stock 1-Wire libraries which are incompatible with the Grid-EYE Demo supplied. Also, there is plenty of technical information on these boards and their integral parts from a design perspective, but documentation that would be helpful in the development stage was lacking. Such as:

  • Pinouts
  • Min/Max specs for pins
  • What is the 1” test strip
  • Battery size for RTC

 

After really digging into the examples I figured out how to get the Grid-EYE and 1-Wire to work but I still can’t get the MAXREFDES130# to work. However, this is probably due to my own deficiencies because another Road Test has and has posted his results.

 

Parts

MAXREFDES130#

 

The MAXREFDES130# is a building automation design reference shield for Arduino. It provides:

  • a real time clock
  • 8 non latching relays
  • 3 latching relays
  • 1-wire Master
  • Mixed signal I/O with 10 outputs

It is made up of the following components:

 

DS3231 RTC

 

The DS3231 is a real-time clock with the following features:

  • integrated temperature-compensated crystal oscillator and crystal.
  • battery input
  • maintains seconds, minutes, hours, day, date, month, and year information. automatically adjusted for months with fewer than 31 days
  • corrections for leap year.
  • 24-hour or 12-hour format
  • Two programmable time-of-day alarms
  • programmable square-wave output are provided

 

MAX4822

 

The MAX4822 is an 8 channel relay driver with powersave mode. All relays can turn on/off simultaneously with a single control line.

 

MAX11300

 

The MAX11300 is an integrated mixed signal I/O device with the following features:

  • 12-bit, multichannel, analog-to-digital converter (ADC)
  • 12-bit, multichannel, buffered digital-to-analog converter (DAC)
  • general-purpose input port (GPI)
  • general-purpose output port (GPO)
  • analog switch terminal.
  • two external temperature sensors track environmental temperature
  • Adjacent pairs of ports are configurable as a logic-level translator for open-drain devices or an analog switch.

 

DS2484 1-Wire master

 

The DS2484 is an I2C-to-1-Wire® bridge device with the following features:

  • (100kHz max) or fast (400kHz max) I2C masters
  • can be powered down under software control
  • dual-voltage operation
  • sleep mode

MAXREFDES131#

 

This is a module that encapsulates the Grid-EYE on a 1-Wire bus. It is made from the following components:

 

DS2413

 

The DS2413 is a dual-channel programmable I/O 1-Wire® chip. It has the following specifications:

  • 20mA
  • voltage up to 28V. (continuous application of voltages up to 28V max.)

 

DS28E17 1-Wire-to-I2C

The DS28E17 is a 1-Wire slave to I2C master bridge device. It has the following features:

  • (100kHz max) or fast (400kHz max).
  • unique 64-bit ROM registration number
  • Multiple DS28E17 devices on bus

 

AMG8833 (Grid-EYE)

 

This is a Panasonic Grid-EYE infrared sensing array. It has the following features and specifications:

  • 8X8 thermopile array
  • Low and High gain modes
  • -0C to 80C range
  • 2.5C accuracy

 

Project Goals

 

My main goal for this Road Test was to determine if the Grid-EYE and Automation shield would in any way help me with false positives caused by animals and other vibrations when using a spring switch as a window sensor in a security application. I am also RoadTesting a Bridgetek CleO35 tft screen so I used this display to show and capture my results.

 

 

I mounted this in an old Radio Shack phone I had in my junk electronics bin. One reason I used this is because it was about the only thing I could find that was large enough to hold the 130. Then it became apparent that I could hang this on the wall or use it on a desk with a stand so I could easily start and stop the Grid-EYE software. It just seemed like good ergonomics at that point. There were also plenty of holes in the case to route wires through from the main board later.

 

I wrote a program to display the Grid-EYE data on a CleO tft screen attached to a NerO Arduino. I simply hijacked the Grid-EYE Demo supplied and added code to display the temperature data that is sent to the serial line as graphical output. I also added a configuration screen to set the min/max temperature and colors.

 

Here is a brief video of the testing application I put together. in this video I change the two colors for the gradient, I change the temperature, I show the Fahrenheit and Celsius settings, then I run the Grid-Eye and wave my hand in front of it. Note that a few seconds pass while I rotate the Grid-Eye into the correct orientation before I begin to make hand gestures.

 

 

 

Results

 

I was not able to get the MAXREFDES130# demo to work in time to test the power consumption or to do the signal analysis I had hoped to do. However, I did put the Grid-EYE to the test and got my feet wet writing some code with the provided Grid-EYE library -- OWGridEye.

 

The Gid-EYE as setup on the MAXREFDES131# with the default settings cannot detect anything through a window. This includes:

  • an inside to outside window with a screen
  • an inside to outside window without a screen
  • an inside to inside Plexiglas window such as are used in a commercial location.

 

I also tried putting black dots on the window as a temperature point, but this wasn’t helpful.

 

The Grid-EYE works great if it is unobstructed line of sight.

 

left hand gesture at 24 inches

 

person @ 5 ft

 

person @ 10 ft.

 

 

It may still be a possibility to get this to work through glass but I would need to write a wrapper class for the Grid-EYE example code to accept the different parameters for the Grid-EYE. The thing that has attracted me the the Grid-EYE sensor is that it can be set to a high gain mode with better accuracy. The Grid-EYE is also capable of detecting Temperature gradients. However, with the basic example provided it is just not sensitive enough. But not many IR cameras are.

 

Summary

 

I did impress my client while gathering part of the data on location and I would recommend the Grid-EYE for an indoor commercial setting. The ability to daisy chain Grid-EYEs together on a 1-Wire bus with RJ-25 lines make this a prime choice for security in this setting. So hopefully the silver lining in my failed glass experiments are sales.

I think the only thing the MAXREFDES130# lacks are good software libraries. Bringing these pieces  to the Arduino is a great idea, but going forward I think Maxim should keep in mind a few principles that make Arduino so attractive for prototyping. Arduino gained it’s popularity by making rapid prototyping with microcontrollers possible by providing not only an IDE, but by providing a simple IDE with very easy to use libraries. There is a reason an Arduino project is called a sketch. Most of what I do on Arduinos is just that – sketching. I find it tantamount to a white board for microcontroller prototyping. What Maxim has started by bringing this over from MBED is definitely going in the right direction. However, in its current state they may miss many hobbyists that aren’t up to digging into the details of the pieces they have brought together here without good libraries. I do see that in its current state this is good for an MBED developer to do some prototyping with an Arduino without worrying about all of the overhead of the MBED platform and all the complexities that can be caused during early design stages. This is a great kit in that respect because the end result is using these pieces as peripherals to a Cortex type setup.

 

The good that came from this Road Test is there is now a fun way to use the 1-Wire protocol on the Arduino platform. In fact, what could be more fun than capturing data from an infrared sensor.

 

The documentation is probably a 3 on a scale from 1 to 5. All of the parts are indeed documented, but they are not documented for implementers in one place. Also the examples for the Arduino seemed to have been rushed out. There seems to be plenty of code for MBED, but the Arduino seems like an after thought. But, I’m sure Maxim is working on this and it will improve.

 

I had trouble with the Mixed I/O code for the Arduino and I was really looking forward to using that part, even though I didn’t mention it in my proposal. Also, the Grid-EYE not giving me any data through glass beyond the pane of glass in front of it was a downer.

 

What's Next

 

What I will do with this from here on is improve my basic housing, get the software for Arduino working, and I would like to try this with the STM32 platform.

I have this mounted up in a telephone as a case, and my next step is to add connectors from the terminals on the inside to the outside. The basic design for this is very functional for me. It can set on a base for easy access to the screen, and it can also be mounted on the wall, out of the way, for basic use.

I haven’t given up on using the full features of the MAXREFDES130. My first step is to re-write the code for the Grid-Eye demo in a way that is compatible with the 1-Wire libraries that I pull from the Arduino IDE. Then I will look at this review closer to see how to get the 130 up and running.

Anonymous
  • Hi Kas,

     

    The SLR lens is only intended for NIR up to about 1 micron.

     

    It "might" focus the longer wavelength IR, but I suspect that the lens material is not transparent enough to get much energy through the lens.

     

    As I recall, the "glue" used to stick the different lens components together absorbs IR.

     

    5 to 14 microns is a whole new realm of materials than the normal materials used for 4. to 1.1 microns used in silicon sensors.

     

    Do some web searches.  I know those types of lenses exist, though they  are expensive as I recall.

     

    DAB

  • I was thinking of using a SLR lense

    Have a look for one that has a seperate mark for IR.

     

    Because the frequency is different, the older manual lens had a different marking when using IR film.

     

    Mark

  • This is interesting because I was thinking of using a SLR lense to attempt to get some focus of objects onto the sensor. I'll have to look into that now as I would hope that grade of glass to be transparent to most frequencies of light including IR.

     

    Kas

  • Hi Fabio,

     

    Yes, you will need either a very pure quartz or sapphire glass.

     

    At 5 to 13 microns you will need some very emissive objects to get through most normal glass material.

     

    Thanks

    DAB

  • The lens and the optical filter of GridEYE form a band-pass characteristic for wavelengths between 5 and 13μm (Far IR). Finding the right type of glass (and of the right thickness) might prove tricky. I tried using some photo frame glass  about 2mm thick, which I believe is soda-lime glass , and it is opaque in the IR range visible to the GridEYE. Moreover, the glass needs to be flat, otherwise any curvature would act as an additional lens placed on front of the sensor, shift the focal point of the sensor's optics and consequently causing the infrared image to be out of focus.

    Fabio.

  • Interesting test report.

     

    I am curious.  Did you use a single glass pane, or double pane window?

     

    Do you know the composition of the glass used for the window pane?

     

    Was the Grideye up against the window or in a position where it would see reflections?

     

    The IR sensor should have seen through a single glass (silicon) pane unless there were IR coatings.

     

    A normal double pane window has IR absorbing gas in between the panes, which could affect your results.

     

    A number of plastic polymers used between some glass pane windows also absorbs IR.

     

    So I am very interested in more details about your test set up so I can fully understand why the Grideye did not work.

     

    I would appreciate your doing some more testing for me.

     

    Thanks

    DAB