💬 Sensebender Micro

  • Mod

    I am thinking of expanding the Sensebender Micro and learn Kicad in the process.

    Unfortunately every attempt to convert from Eagle to Kicad failed.

    Is there a Kicad version available or did any of you manage to convert the project?

  • Admin


    There is no kicad project available for the Sensebender Micro, I tried to convert it myself, but didn't succeed with it either.

  • Admin

    @tbowmo said in 💬 Sensebender Micro:


    There is no kicad project available for the Sensebender Micro, I tried to convert it myself, but didn't succeed with it either.

    I haven't tried this Eagle->KiCAD convertor myself but it might do the trick or at least reduce a lot of the manual labor to convert...

    There's even a tutorial video.

  • Admin


    thanks for finding that tutorial.. Might give it a spin, and see if I can convert the sensebender micro to kicad

  • Mod

    @blacey I tried that one but for some reason a dialog pops up that I can not click away anymore 😞
    Complaining about files in a wrong place without giving more info.

  • Admin

    @marceltrapman The author updated his repo within the past few days so you could open an issue on his GitHub repo to see if he can help...

  • Admin


    Just tried the scripts from the url that @blacey mentioned above on the sensebender micro eagle files.. And got a semi working thing in kicad..

    And it seems that at least the forward annotation from schematics to pcb is working like it should..

  • Mod

    @tbowmo Nice, I will try again (probably sunday or so)...

  • Hey together,
    i have a question, because i have some capacity troubles. I used the example sketch from sensebender micro that meassures the temperature and humidity but i have additional activated the signing and encryption and now i got over the availible space 109%.
    use anybody from you all the features? what i have to do?
    thank you

  • Re: 💬 Sensebender Micro
    I'm trying to flash the sketch to the sensebender micro using the Arduio IDE.

    I bought the sensebender micro with the suggested FTDI programmer.

    I connected the programmer to the sensebender and plugged in the USB cable.

    My windows 7 installation finds the device and installs the driver as USB Serial Port (COM3). The driver is from FTDI. The hardware device id is: FTDIBUS\COMPORT&VID_0403&PID_6001

    In the Arduino IDE, i've selected Board: Sensebender Micro, Processor: Atmega 328 8Mhz, Port: COM3.

    I tried using USBasp, made a clone with the right hardware id's and tried that. I tried AVRIsp Mk II.

    Whatever i try, avrdude.exe tells me it can't find the device:

    C:\Program Files (x86)\arduino-1.8.1\hardware\tools\avr/bin/avrdude -CC:\Program Files (x86)\arduino-1.8.1\hardware\tools\avr/etc/avrdude.conf -v -patmega328p -cRF232RL -Pusb -Uflash:w:C:\Users\rob\AppData\Local\Temp\arduino_build_955073/SensebenderMicro.ino.hex:i 
    avrdude: Version 6.3, compiled on Dec 16 2016 at 13:33:19
             Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
             Copyright (c) 2007-2014 Joerg Wunsch
             System wide configuration file is "C:\Program Files (x86)\arduino-1.8.1\hardware\tools\avr/etc/avrdude.conf"
             Using Port                    : usb
             Using Programmer              : RF232RL
    avrdude: Warning: cannot open USB device: Function not implemented
    avrdude: error: could not find USB device with vid=0x403 pid=0x6001
    avrdude done.  Thank you.
    the selected serial port 
     does not exist or your board is not connected

    Anyone knows what's wrong?

  • Hey together,

    i have an problem, i had some troubles with the space on the sb micro, i have removed the #define my_debug that solved my space problem, but now i have observed that the node is starting and sends few times the temp and humidity but after the few times nothing happens anymore.
    i observed, when i hold the sensor in the fingers so that it will be worm, and start the node then it sends all minute the temp, but when the temp goes down to the room temperature then the node should send only when the humidity or temp changes over the threshhold, so in the room i dont have much changes and i think that when the node does not send about a longer time, that the the problem comes up.
    I tested it in some different distances, on another floor but in very short distance too. I dont think that is a radio problem.
    What do you think about?
    The Problem is, that i cant debug the node because i disabled it because of space problems.
    Thank you

  • i have just tried it again, it worked for 20 minutes. After them i get this output:

    Sensebender Micro FW 1.4 - Online!
    isMetric: 1
    TempDiff :122.28
    HumDiff  :154.00
    T: 22.28
    H: 54
    TempDiff :0.00
    HumDiff  :0.00
    TempDiff :0.10
    HumDiff  :0.50
    TempDiff :0.11
    HumDiff  :0.50
    TempDiff :0.12
    HumDiff  :0.00

    ok one more thing i found, when i close the serial monitor and start it again, i get the correctly output again, and i see in fhem the new readings.

    but i cant understand what happens why stop the node to transmit the correct readings

  • @meddie, do you use the default sketch for sensebender ?
    If this is the case, please notice that after 5 measures, the clock speed is lowered to 1 Mhz. It means that the serial output won't work anymore using the default baud speed.
    And, when you restart the serial monitor, it starts all over again from measure number 1.
    Hope this helps.


  • @qqlapraline
    oh yes it does! It explains why i get the € signs in the serial monitor. But why does the node not send to my FHEM Controller? Depends it also on it, that the node switch to 1 Mhz and cant send anymore?
    Thank you very much for your answer, its very helpfull.
    Greets Eddie

  • Admin

    Hmm I actually thought that this feature with switching to 1mhz was removed, as my calculations show that it (in theory) will use more current, than running at 8mhz (due to the fact that it sleeps most of the time)

  • @tbowmo : The code to switch the frequency back to 1MHz is still there at https://www.mysensors.org/view/1/Sensebender-Micro.
    Should it be removed?

  • Is it possible to directly connect a RFM69* module to the Sensebender Micro? Or do I need the (rather costly) NRF2RFM69 to do that?

  • Mod

    @Wavemaker welcome to the community!
    You can spend your time instead of your money to do exactly what the adapter does, no need to buy it.

  • Admin


    What is costly? If you grab the gerbers for the nrf2rfm69, send them to dirtypcbs (or use the link provided in the thread and order the pre uploaded gerbers at dirtypcbs) you'll get around 30 modules for 12$..

  • @tbowmo Aha, yes, well I was looking at the cost of just one adapter to test. But you're right, in larger quantities it's not costly.

  • @Michiel-van-der-Wulp
    Can you tell me where in the code is the switch to 1 MHz? I still have the problems that my node dosnt send anymore. It works for several hours but after then it dont send anything.

    In programming i am not good, and so i cant find the switch.
    Thank you very much.
    Greets Eddie

  • @meddie : Sure, I can:

    The following is an extract from the code shown at https://www.mysensors.org/view/1/Sensebender-Micro, from the "loop()" function:

      if ((measureCount == 5) && highfreq) 
        clock_prescale_set(clock_div_8); // Switch to 1Mhz for the reminder of the sketch, save power.
        highfreq = false;

    If you remove these lines, it will stay on 8MHz.
    (I did not test this but I am quite sure)

  • @Michiel-van-der-Wulp
    thank you i will test it the next few days

  • I assume there is no exposure to the SPI bus on this board?

  • Hardware Contributor

    @Dominic-Amann from the hardware site:

    MYSx 2.6 with
    Dedicated UART
    Dedicated SPI
    Dedicated Interrupts
    I2C bus (shared with onboard eeprom)

  • Ah - right, the radio connector uses SPI.

  • Admin


    There are multiple SPI ports in use, one of them is dedicated to the expansion header (which follows MYSx 2.6 standard)

  • Can somebody please post what this boards current draw is at 8Mz w/wo a radio. Because it will live in a crawl space It's going to be plugged in. I've also added a very simple water detector.

  • Admin


    normal operating frequency is 48Mhz (if I remember right).. If I remember right, then there is no options in arduino to switch the frequency to 8Mhz..

  • Beware that the Si7021 can return a RH value < 0 or > 100, and Domoticz will not store it. Clamp the humidity to a valid range to avoid losing values.

    Lately, my Sensebender reported values of 101-104 during the night. Took me some time to understand why Domoticz complained it didnt receive any values.
    It received these values, but didnt like them.

    See section 5.1.1 of the Si7021 datasheet says:
    Due to normal variations in RH accuracy of the device as described in Table 4, it is possible for the measured value of %RH to be slightly less than 0 when the actual RH level is close to or equal to 0. Similarly, the measured value of %RH may be slightly greater than 100 when the actual RH level is close to or equal to 100. This is expected behavior, and it is acceptable to limit the range of RH results to 0 to 100%RH in the host software by truncating values that are slightly outside of this range.

  • So cool that the micro as a node reports its battery level to the UI (I'm still on the FTDI power, hence > 100%)


  • Is there a board definition for sensebender micro for PlatformIO available ?

  • Plugin Developer

  • Am I able to remote reboot the sensebender micro? I can send an OTA firmware if i manually press the reset button.
    but can i use the reboot command in MYScontroller? it doesn't seem to do anything when issued.

  • Admin


    Is it the default dualoptiboot bootloader? Then the bootloader itself does not support OTA FW. You need to put a sketch on it, that supports OTA. (Default sensebender micro sketches doesn't)

  • @tbowmo said in 💬 Sensebender Micro:


    Is it the default dualoptiboot bootloader? Then the bootloader itself does not support OTA FW. You need to put a sketch on it, that supports OTA. (Default sensebender micro sketches doesn't)

    yes it's the default bootloader. yes i have OTA added to the sketch. it works if i reset the device via manual reset. but what i'd like to do is send the reboot command from myscontroller. but it seems to do nothing ever. does the bootloader support reboot? or is that something i also have to add to the sketch?

    situation: i have about 15 sensors all over the house. if i update, i'd like to be able to assign the firmware, and then issue the reboot command. so upon reboot, they take the assigned firmware. what i don't want to do is have to go to each one and manually press the reset button to get it to take the firmware. i'm sure it's healthier to run up and down 3 flights of stairs. but i'm lazy 🙂

  • Admin


    The sketch should support reboot, try sending I_REBOOT to one of your nodes (info can be found here, look under internal messages)

    I haven't tried it myself yet, as I haven't touched my sensebender micros for ages..

  • Hi,
    Three questions regarding SenseBender Micro:

    • What board should I configure in Arduino IDE in order to upload sketches? Would it be equivalent to Arduino mini pro, or is there any "board library" to load ?(Didn't find it, Woudn't it make sense to be included in the examples/Libraries pack?)...
      (Found it: https://github.com/mysensors/ArduinoBoards . If you look between the photos above there is a simple link lost in the between)
      MySensors Admins: Just a small suggestion: As it is now, - a simple link between photos is easily overlooked. Can't you place it near the specs where it should be more visible?

    • It has an I2C bus for the SI7021, but it seems the ATSHA204A (which I believe its I2C also) is connected to another pin (a3). Does this mean it has two I2C buses?

    • Can anyone confirm that the port that measures the battery voltage is A0?


  • Contest Winner

    @joaoabs we do not support I2C variant of atsha204a. Only single wire variant.

  • Admin


    It uses the internal vref to measure the battery voltage. Some of the theory is described here https://www.sciencetronics.com/greenphotons/?p=1521

  • For the battery powering voltage measuring do you mean that this is not needed after all? (https://www.mysensors.org/build/battery#measuring-and-reporting-battery-level)
    It would be just a matter of enabling the flag "#define BATT_SENSOR 199 " and no resistors needed?

  • Admin


    Yes, when you power it directly of f.ex. two AA batteries, then you can use the secret trick mentioned in that article that I linked to, for measuring battery voltage without external resistors.

  • Sorry for the dummy question, but my SenseBender Micros came with a small white sticker on top of the Si7021 sensor (like in the pictures above). Is it supposed to be removed or to stay like that?

  • Contest Winner

    @joaoabs the datasheet for the device clarifies that I believe

  • Admin


    Just leave it on..

  • Hello!

    Help me understand why the sketches are not loaded in Sensebender Micro - there is a synchronization error:
    avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x82
    avrdude: stk500_getsync() attempt 9 of 10: not in sync: resp=0x82
    avrdude: stk500_recv(): programmer is not responding

    • FTDI connected via 3.3V jumper

    • Another device built on the SB Micro with SB bootloader is also not flashed with the same error, but on the PC of my friend, sketches successfully loaded into the device and on my PC are given the correct data when working sketch

    • device and serial port are selected correctly

    • mySensors Lib and device packs(AVR, SAMD) installed with standard lib and device managers(and also added path https://raw.githubusercontent.com/mysensors/ArduinoBoards/master/package_mysensors.org_index.json in the settings menu)

    • at the same time if I take a pure Pro Mini and load into it any sample sketch of mySensors package - it will successfully do it and will work.

    What am I doing wrong and how do I get the Sensebender Micro to take sketches?

  • Admin


    Did you select the sensebender micro as target in Arduino? Is it the same FTDI device that is used on both computers?

  • @tbowmo
    Yes, of course, I chose the target device "Sensebender Micro -> "Atmega328p, 1mhz" and "Atmega328p, 8mhz"(for device (RGBW controller) based on SB Micro with 8Mhz quartz resonator).

    I tried three different FTDIs.

    With any other Arduino (with native loaders) there are no problems with these FTDI adapters.

  • @nailman At what Mhz does your RGBW Controller is running now?
    It seems to be the problem is in identifying the correct board.

    If I have a board running at 1Mhz and try to program it at 8Mhz, similar to your error would come up, i.e. not in sync

  • Admin

    Unless the bootloader is reprogrammed, then it defaults to 8mhz, and you have to actively set registers to run at 1mhz in your sketch.

    Do you have a ISP programmer? If yes, could you make a memory dump, and send it to me?

  • Hello,
    Coming back to the battery powering topic: I was checking some SlimNode code and it uses #include <Vcc.h> library to report battery level. I can see in that the example code above doesn't use it. Does anyone know what is the difference? Which is better?

  • Admin


    Could you post a link to the code from slimnode?

  • Hi,

    The slimnode original thread has a few (not sure anymore which example I'm using now because the thread is huge and I've lost track of it)
    Here is one example:

    and other:

  • Admin


    The library use the exact same method to read VCC, as the Sensebender Micro example. It's just the functions that is extracted into a library (which I think have been done by @Yveaux )

  • @tbowmo
    I apologize for the delay in replying, I was very busy with work.

    It turned out to be some mystical incompatibility of the FTDI and Sensbender Micro or a device based on its loader. Three versions of my FTDI refused to work with Sensbender Micro, but they worked with regular Arduino, and the fourth one, bought on AliExpress, works perfectly normal. Externally, all the same, only those that do not work with Sensbender Micro, the labeling of the chip differs slightly in the quality of engraving on the plastic.

    Maybe it's fake or some kind of non-standard chips.

  • @nailman There are a lot of fake FTDI modules. Some are labelled FTDI other claim to be FTDI but are CH340. Some have DTR others RST and good ones like Adafruit Friend it is selectable.

    My recommendation is do not try to save a few bucks here. Spend money on a good quality FTDI adapter like Adafruit Friend.