This is my personnal blog

Before entering or getting informations from this blog, there are some things you need to be aware

This site is intented to be used by myself, informations located on the site are really used more as a reminder than descriptions or similars How-to. I do my best so you can use information, and sharing knowledge sounds good to me. The information may help some or be usuable by others, so that’s why I decided to share them. But please, don’t tell me that they are too short or even unusuable.

About me ? I’m a IT manager by day, aspiring creating electronic embeded devices by night, and this is my blog. I live in Poitiers, France.



  1. Hi:

    I am trying to purchase 3  x Arduipi boards from http://www.seeedstudio.com, but their purchasing portion of their web site is broken and their technical and customer support has not replied to my last messages.

    Is there another way that I can get 3 of the Arduipi (the sheild that brings arduino to raspberry pi)?



    • Hi Cindy,

      I’m glad you like the arduipi board.
      Seeedstudio is the only distributor for the board.

      This is strange because seeed site always worked for me. They are very serious and I think the problem will be solved tomorrow (chineese local Time)

      If you have any question about Arduipi do not hesitate to ask, I’ll be happy to help.



  2. Hi Charles-Henry,

    Have you advanced documentation for your DAC-Shield as yet? I am needing a multiple 1-!0V drive circuit to control LED luminaires over Ethernet for a home automation project and your circuit looks like a good solution to trial for this purpose.



    • Hi Dion,
      To be honest I’ve not worked on this board until I designed the PCB, I’ve got all the components and the PCB but did not took time to work on it since I’m working on others projects for now.
      I’m always thinking to populate the PCB, solder the components and test the whole batch but it’s not in my top priority.
      Also I didn’t find a library to drive the DAC 7565 so I need to write it from scratch, and this is really taking time that I do not have for now.
      I can help if you want but I won’t be able to do all the needed work on this shield for now (but it should work out of the box).

      Just let me know


  3. Charles,
    The files at GitHub for this DAC board look like code. Is this correct? I have looks for a shield for the Arduino Uno that this one does for a long time. Desired it to be assembled. No joy on this quest. Thank you for providing the design. Is there a parts list to be found? 6 copies have been ordered from OSH Park and will be assembled soon if parts are in hand.

    Thank You,

    • Hi John,

      I’m glad this board could be interesting for you and I apologize for the lack of documentation, it’s because I started this project and then switched to over now, so it’s not really finished but could be a good starting point.
      The files on Github are the file I used for the PCB design. Hardware should work ok if I did not done any mistake on PCB design, it’s more a “test” prototype for now but I really would like to make it working. I’ve got some PCB in my hands with all components but did not had time to solder, assemble and test. So you really should consider these board as testing.
      By the way, no Arduino code exist for driving the DAC, I would like to create a dedicated library for the DAC7565 but I’m currently working on other projects. But I will be glad to help on software version as soon as will have working hardware on my hands. I’ve also put on the board a 2 DAC-out with IC2 A and B using Arduino PWM output. I do not know it it’s works, but if it is, it could avoid us to use DAC7565 chip, it’s just for POC.

      Of course I can help you to make this board working and validate all is okay. So if you need any help do not hesitate to ask me, I would be happy to put some time on this project and collaborate with you to finalize this board, but for now I’m not ready to do everything alone due to time issues. I can get some time but not enough to do all.

      I now this project is really in starting state, I hope all the information will be enough for you to start working on it and achieve your project. If you build 6 boards, if you don’t mind, I’d really be interested to have one for testing with just the basic components, I do not need OLED, Connectors, Rotary encoder or WS2812 which I can send it back to you after testing. This could permit to start working on Arduino Libray for the DAC.

      Let me know your investigations and if the hardware (at first) is working good.

      Have fun


  4. Charles,
    Forgot to ask. Are all chips on Arduino DAC board SOIC?

    • John,

      I’ve pushed the BOM file on Github repository as Excel file. The TL72 and LM324 Amp op can be replaced by any type of Op Amp you have, until the pining is the same.
      All are SOIC except the DAC7565 which is TSSOP-16


  5. Charles,
    Thanks for responding and posting at Github. When I get the DAC boards assembled you will get one! They will be upgraded with the DAC8565. It is 16 bit resolution for really smooth Analog output. The best parts will be used. 3 channels will be used to drive Parker BD99 servo drivers on 2 flight simulators each. This as a near perfect shield for my needs. Lots for appreciation for help. Talk soon my friend. John

  6. Ok Charles if POC is realized with the DAC design and made usable with Arduino, production and marketing may be in order. Many enthusiast will appreciate this shield. I look forward to being a part.
    Bless You,

    • John,
      Thank you this is a great news. This mean that the dac you’re using is pin comptatible with the one I choosed ? Also you have a library for this version ?
      It’s always great to share hope it Will work fine 😉

  7. The DAC upgrade is a drop in upgrade. The 2 are pined the same. I went to TI website and confirmed their pinout. The library will be a modified version of a simulator motion software SMC3. It was compiled by a forum member at Xsimulator website. A question I have is how 0-10v analog output obtained when no voltage input to opamp. Please expand as my understanding is limited.

    • John,

      Since the RSTSEL pin is connected to ground, the datasheet says that at reset the outputs of the DAC are set to 0 scale, so 0V, that means that there is no way to have AmpOp input unconnected so output will always be between 0V and 10V.
      The Op Amp (powered with VIN that should be of course at least 10V but says 12V to be sure) is just a x 2 amplifier to be able to have more than 5V at output.
      This means that, as DAC is powered to 5V (like the Arduino) the output are as follow :
      – Programming Full scale of DAC from Arduino give you 5V at DAC output and 10V (5V*2) at OPAmp output
      – Programming Mid scale of DAC from Arduino give you 2.5V at DAC output and 5V (2.5V*2) at OPAmp output
      – Programming Zero scale of DAC from Arduino give you 0V at DAC output and 0V (0V*2) at OPAmp output

      Hope this will answer to your question


  8. Charles, the explanation you give does help. I stumble along as learning increases. Thanks for circuit operation.

  9. Hi Hallard,

    Felix of Low Power Lab posted your RFM69 Lib and told me that you may have added a dual radio capability in your lib. Is this true?

    Just trying to confirm this before I dig into your library.

    Thank you very much,

  10. Hi Donald,

    Well, it should be, in fact what I’ve done with success is to have one Arduino board with 2 modules (one RFM12 and one RFM69). For this I needed to change both libraries to have the possibility to change the IRQ  and CS pins which can’t be shared.

    For this I added new function on both libraries, one to set IRQ pin and the other to set CS pin to be able to change them on the fly after instantiation. It’s working because I’m sure sensible code (IRQ handler) is not shared because there is 2 libraries and 2 different code.

    For example

    – RFM12B connected IRQ to D2 (INT0) and CS to D10 (SS)

    – RFM69 connected IRQ to D3 (INT1) and CS to D9 (example)

    then in my code declaration

    RFM12B radio; /* default INT0 and SS */
    RFM69 radio69(D9, D3, false, 1); /* CS=D9, IRQ Pin=D3 (INT1), IRQ handler=1 for INT1 */

    but if you want to have 2 RFM69, with Felix’s original library you can pass all these parameters, so you don’t need my library until you want to change pins after instantiation. Default Felix’s one should be working with something like that:

    RFM69 radio1(); /* default so CS=D10, IRQ Pin=D2 (INT0), IRQ handler=0 for INT0 */
    RFM69 radio2(D9, D3, false, 1); /* CS=D9, IRQ Pin=D3 (INT1), IRQ handler=1 for INT1 */

    It should work until compiler does not do any optimization on shared code/variable for the class (but it should not) but I did not tested, should be interesting to know if it’s really working if you want to go to this adventure. Let me know  😉

    Another technique less straight forward if the 1st one is not working could be to duplicate the lib and change on the clone one (renaming source file also) the class RFM69 to RFM69_1 for example, like this compiler will treat as a different class.
    RFM69 radio(); /* default so CS=D10, IRQ Pin=D2 (INT0), IRQ handler=0 for INT0 */
    RFM69_1 radio_1(D9, D3, false, 1); /* CS=D9, IRQ Pin=D3 (INT1), IRQ handler=1 for INT1 */

    Oh, while wrintig this answer, you may also need to take care that talking to SPI devices is done with interrupt disabled (or in IRQ) to avoid both SPI devices bus conflict (but I think Felix already done this in his code)





  11. Truly impressed for taking the time to help someone whom you never met.

    Thank you a with a 90 degree bow.

    Yes, I will proceed and will let you know how it turn out.

  12. Hello,
    Would it be possible to purchase just the ArduPi pcb/board only?

    • Hi Michael,

      Thank you for being interested. Unfortunately I do not have any PCB board, nor Seeedstudio. But as the project is Open Source I think you can try to make them build by any PCB provider (Seeedstudio, DFRobot, ITead,…) You will need to order 10 boards and it should cost you approx $20 (for 10) as far as I remember.

      But take care, some components really need good soldering skills and/or reflow oven. In fact I thought during conception to be able to provide the board with only small parts, but we didn’t and keep things simple because we had no idea of people interested by PCB only.


  13. Hi Charles-Henri,

    I am using your excellent TH02 library on Moteino. I have one sensor outside my house, with minus degrees celsius. However the TH02 lib reports the absolute value, without the minus prefix. E.g. “6.5” instead of “-6.5”. Please advise on what I am doing wrong.

    Merci beacoup,

    From the Arduino sketch:

    int16_t temp, rh, rh_comp;
    //uint8_t status;

    Serial.print(F(“Starting Temperature conversion.”));

    // Get temperature calculated and rounded
    temp = sensor.getConversionValue();

    // Display unrounded value (raw)
    Serial.print(F(“Temperature = “));
    // this call does not do any I2C reading, it use last reading
    Serial.print(F(” C => “));
    // Display now rounded value returned by 1st call
    Serial.println(F(” C”));

  14. To centralize support and let the reading easier, I’ve just disabled comments on posts. This does not mean it’s no more possible, but the way to discuss has been improved and is now much cleaner to find usefull information using the forums

    Thank you very much for you cooperation.



34Comments are closed.

Comments on this topic in community Forums.