1. shane cissell

    Hello im trying to build two lamps with 18 10 watt rgb leds in each lamp. what is the best price you could give me if i orderd 36 sheilds from you. thanks Shane

    • Hi Shane,

      I hope you realize that this shield is not yet produced in numbers. At the top of this post I mentioned that I am in process of creating a fund raiser at and hope to complete that this weekend.

      The original shield cost $40 without stackable Arduino Headers, $41.50 with headers and $45 including the temperature sensor. I am hoping to be able to keep the pice in that region. You can expect a discount when ordering such a large quantity, but what this would be specifically has not been determined.

      The price drop for electronic components when going from a Quantity of 50 to 100 is significant. Also non recurring cost e.g for set-up pick-and-places, would be spread over a larger number of boards. We initially targeted having 50 boards made. If the price is not outright discouraging you from using this shield in your project I would target having 100 shields made for the first batch and I would expect the price we’ve been quoted for 50 to come down a bit.

      • shane cissell

        Hello I think we can work something out can you call me 702-677-1717 thanks shane call any time between 7 am 10 pm i live in las vegas

  2. I’m interested in buying a shield as soon as the Tindie fundraiser is up. Thanks!

  3. I am also interested in buying a shield.

  4. Joseph Raimondo

    HI, I would be very very interested in buying atleast 1 (but possibly more) of these shields. Would you be able to ship to the uk?

  5. I’m interested in buying 4 of them

    • That is great to hear. I chatted with the folks at today and was told that the Fundraisers will be back online next week.
      While delays are relatively normal, I’d say that within the next 2-3 weeks the LED shield project will start as a Fundraiser on I will send an email notification to all who have voiced interest here on the blog.

  6. Hello,

    I search a good driver for dimming 10 to 12 groups of HP leds with two of them at 1000mA.

    Vf If (mA)
    1 group 15,52 700
    2 groups 21 700
    1 group 24 700
    1 group 15 700
    2 groups 20,35 700
    1 group 13,86 700
    3 groups 22,96 700
    1 group 26,4 1000

    As I want to command them with I2C bus, your product seems to be good.

    Does your Fundraiser start ?

    • Hi,

      If I interpret your brief information correctly that should work out to three shields. The last group you can only run up to 700ma, however, as that is the max constant current the driver chip on the shield can provide. Of course you can connect 1000ma LEDs.

      Unfortunately we have a not been able to start the Fundraiser on Tindie. My Partner in Germany is very tied up with his professional work and I am currently investigating US sources, including making the shields myself!

    • Actually, after calculating wattage you’ll need more than three shields. The shield is rated for up to 40W. When you add the total wattage of the first and third three groups you’ll exceed 40 Watts.

      Perhaps you tell me a little more about your application so we can see what can be done.

      • Hi,

        Thanks a lot for your answers.
        Can you send me your email ? It is easier and more confidential.



  7. Hi. Can you help me with number of HP led shield for my project ?
    I want to control 4 independent channels for color mixing.
    First channel with 32 leds with Vf=3.2 V
    Second channel with 16 leds with Vf=4.0V
    Third channel with 12 leds with Vf=3.5V
    Fourth channeů with 8 leds with Vf=2.6V
    This average current will be mostly 350mA. But sometimes in some output it can go up to 500mA.
    I plan to control all these leds from raspberry pi with combination of analog dimming and pwm dimming. If it is possible I will do the color mixing with analog dimming to get best lm/W efficiency.
    So I think I will need at least 3 HP LED Shields. Am I right ?

    Another question I have is about constant current. You have at specification this:
    “Dynamically adjustable constant current 100mA – 700mA per channel allowing for analog dimming.”
    Is it possible to use analog dimming to dim less then 100mA current ? Can I dim to 0 mA with just only analog dimming or do I have to use PWM dimming for lower currents?

    I have also found very similar led driver LT3492 in the same package with 60V PVin and 600mA for each output. Do you think is there some advantage to use this driver in my project instead of yours LT3496 ? Is it possible to optionally assemble this driver in your HP LED shield project ?

    Thanks for any comment.

    • Hi Marty,

      I will send you a PM for more specifics. In general I would not recommend Analog Dimming for color mixing for several reasons that I don’t want to go into too much detail here. While analog dimming is slightly more efficient than PWM dimming PWM dimming provides a much larger dimming range 3000:1 needed for smooth fading.
      Also Analog Dimming below 100mA is possible but definitely not down to 0.

      Yes, you need at least three but likely 4, because if you assume 3 channels for the 32 3.2Vf LEDs you’d run each channel at 34.1V, which is too close to the max output voltage of the shield of 36 if you could reduce that from 32 to 30 you should be OK. Or you could find different LED’s.

      In general I personally try to stay away from the very cheap stuff that does not come with a decent spec sheet from a reputable company.

      It is unfortunately not possible to simply replace the LT3496 with the 3492. This would involve a good bit of re-design and prototyping.

    • Hi Marty,

      Did you receive my email ?

      • Hello Peter,
        I’m not at the office now, where I have your emails. But last reply I’ve received from you was around 2 weeks ago. Meanwhile I have send you two emails without your reply. I don’t know on which side is the problem.
        In first email where I haven’t got reply I was sending the links to the leds datasheets and asks some questions about power supply, led distribution, etc.
        Have you got this email ? Should I try to send it to you again ?

      • Hi Marty,

        I received all of your emails and replied the day I received them. That’s the reason why I decided to ask here 😉

        If you have another email address you could leave a post here on the blog. Otherwise I will use another email address and hope that it gets though.

  8. Hi Peter.
    So I investigate what’s happened with your emails. And I found them moved to spam folder at my email provider.It must have been moved by their (email provider) automatic spam filter. I don’t know why it happend but I marked emails from your email address to not go to the spam folder. Sorry for inconvenience.
    I will read all your replies and let you know.

  9. simon georgeff

    Hi Peter,
    Are you currently selling boards? I’d be interested in buying some. Thanks.
    Best Regards,

  10. simon georgeff

    Fantastic! Thanks. I am interested in varying strobe frequencies for high power RGB LEDs (such as CREE MC-ERGBW). Is it possible to colour mix and vary strobe frequency at the same time?
    As an estimate, how many CREE MC-ERGBW could I effectively use with the shield if typical forward current is 700mA and forward voltage ranges from Red 2.3-3.7vF? And finally, can I use standard Arduino programming language to control the shield or do I need to use the specific library on github?
    Well done on a great product too!

    • Hi Simon,

      Yes, you can color mix and strobe at the same time. If using the library it would be the same command. How fast you can strobe depends on how many shields you want to control simultaneously and at what frequency you run the I2C bus.

      Given the example of the Cree I’d say you can connect 6-7 of these LEDs in series before you reach the 40W maximum power. The shield may actually be able to do more, I’ve just never tested it higher. It’s basically a function of how much heat it can dissipate.

      To operate RGBW LEDs you’d need 2 shields because a single shield has only three channels.

      You don’t need to use the library, but it will provide you with a good framework of the I2C commands to use to talk to the chips on the shield. The library is obviously written for a RGB LEDs and not for RGBW LEDs so you’d need to write your own libraries.

      The library is written using C++, which is the normal Arduino Language.

  11. Why, yes I do. I also know the person.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s

%d bloggers like this: