What did you build today (Pictures) ?

  • Hardware Contributor

    @nca78 said in What did you build today (Pictures) ?:

    @fotofieber said in What did you build today (Pictures) ?:

    Testing a CCS811 CO2 sensor.

    Unfortunately this is not a CO2 sensor. It's only a VOC sensor giving an estimated eCO2 value. It's useful to tell you if your room needs ventilation, but not much more. And as even the VOC part is not calibrated it's only good for relative measurement.

    My tests will show, how far away I am with this sensor in my indoor usage scenario.

    My Netatmo sensors claim to measure CO2 and are battery powered. They seem to calibrate themselves to the lowest level they measure in 24 hours. This behaviour seems to be similar with the CCS811. The Netatmo sensors seem quite close to my MH-Z14A.

    In the datasheet for the CCS811 I have read, that you can't use them in your green house, because of its self calibration. Netatmo may have the same restriction too.

    AFAIK the only similar sensors which are calibrated and give absolute values are SGP30 and BME680.

    I have ordered a SGP30 some days ago and will test it too. The BME680 needs binary code linked which is a no go for me. (As a gift I would take it into my test setup. 🙂 )

    If you want to measure CO2 you need a CO2 sensor and it's going to consume a lot of power, at least too much for a battery powered sensor.

    The problem with high power sensors is, that they produce heat, which can make your temperature measurements unusable. 😞

    As my CO2 sensors have a color led to show air quality, they are mains powered anyway.

    [edit] there's also the MiCS-VZ-89TE TVOC sensor, they claim to have a curve of eCO2 not too far from NDIR sensor in their datasheet. But that datasheet is strangely poor in details, they didn't even put any electrical characteristics...

    Thank you for the link. I have ordered one for my test setup. They are really expensive, about twice the price of the MH-Z14A, the SGP30 or the CCS811.

    Other CO2 sensors I should use in my test setup?

    I like the MH-Z14A and depending on my tests may stay with them.

    EDIT: ordered a MHZ-19 for the tests

  • Hardware Contributor

    @fotofieber said in What did you build today (Pictures) ?:

    EDIT: ordered a MHZ-19 for the tests

    Make sure you order a MHZ-19B, it uses less power and has fixed an autocalibration problem.
    SenseAir S8 has a better calibration process using several days, so if you don't ventilate your room during 24h it will not use a wrong reference level and report wrong values.

    And about BME680 there are boards on AliExpress with included STM32 Cortex M0+, basically it's the same than the MiCS-VZ-89. Search for GY-MCU680V1.

  • Hardware Contributor

    @nca78 said in What did you build today (Pictures) ?:

    And about BME680 there are boards on AliExpress with included STM32 Cortex M0+, basically it's the same than the MiCS-VZ-89. Search for GY-MCU680V1.

    Thx, ordered one on aliexpress. Hope I have time to test when they arrive... 🙂
    EDIT: first results, hope CCS811 will calibrate better in the next two days

  • Admin

    @berkseo nice! What did you use for the capacitive sensor? MPR121?

  • Hardware Contributor

    @petewill said in What did you build today (Pictures) ?:

    @berkseo nice! What did you use for the capacitive sensor? MPR121?

    TTP223s in top left and top right corners 😉

    @berkseo I'm curious about that, why not use the capacitive touch function of the NRF52832 ?

  • @nca78 said in What did you build today (Pictures) ?:

    TTP223s in top left and top right corners

    yep 🙂

  • @nca78 said in What did you build today (Pictures) ?:

    I'm curious about that, why not use the capacitive touch function of the NRF52832 ?

    Ttp223 chips suit me. Very stable stuff. When I tried to do it on amtel328, these mcu also had this feature (almost all mcu have this feature). But it was not very stable. I'm not sure that a stable device using the mcu 52832 would be possible. If there is an example of a stable software implementation, I would be happy to test it, and then it would be clear to do it without external capacitive chips or not.

  • Mod

    My new workbench is coming along nicely.

  • Mod

    Top shelf is for network stuff

  • @mfalkvidd good job

  • Continuing along the theme of one of my last projects, I built a nRF52832 into a 328p Pro Mini footprint. Made two versions: One with some edge SMA or U.Fl pads and another with a PCB trace antenna:

    0_1555494186797_Pro Mini 328p vs. Pro Mini nRF52.jpg

    0_1555494248417_Pro Mini 328p vs Pro Mini nRF52.jpg

    I wanted to start getting into using 32-bit microcontrollers (ARM Cortex varieties like nRF5x, SAMDs, STMs, etc.) for some more complex HA and other electronics projects and am trying to ease the learning curve from all my 8-bit ATMEGA experience.

    Keeping the 328p pin-compatible footprint and PCB size means I can still reuse most of my other Pro Mini project boards to get going. An added bonus is the nRF52's ability to remap (almost) any pins, which will no doubt come in handy.

    They’re both two layer boards and I get pretty decent range out of the PCB trace antenna - ever so slightly better RSSI than EByte’s E73-2G4M04S1B, which was surprising since I didn’t really do anything different (that I’m aware of) and their module is shielded too.

    Since there’s no need for a separate nRF24 board and other associated components, like external SRAM or ATSHA, it’ll possibly save me a few $ too! Power pins next to the (remappable) I2C pins make some of the sensor modules (like SI7021) pluggable.

    I also gain 16x the program memory (512K vs. 32K) and 8x the speed (64MHz vs. 8MHz) which is no small increment!

    Some of the project boards I have made use of the Pro Mini 328p’s FTDI pins, so I added a few components to enable the use of an FTDI programmer with custom DFU serial bootloader.

    0_1555494282393_FTDI DFU Serial Bootloader - Pro Mini nRF52.jpg

    Basically, a DTR pin toggle from the FTDI will reset the nRF52 into a state where it’ll briefly listen for a new program - similar to Adafruit’s Feather. You can also force that state for a longer period with a combination button press like Nordic and SparkFun’s development boards.

    I’m unfamiliar with SWD/JTAG programming/debugging and all things GDB/OCD, so I built myself a black magic probe out of a STM32 blue pill and am going to have a play with all of that, along with VS Code and PlatformIO and probably one or two others.

    MySensors nRF52 support worked out of the box (!) - so a huge thanks to all the hard work of the folks round here for getting that up and running. If there’s anything I can help with there, please let me know and if I’m able, I’ll try to take a stab at it (OTA maybe?). Like I said, I’ve got quite a steep learning curve here though.

    On the low power end, I added the DCDC components Nordic recommend too and managed to get the MySensors smartSleep() current down to around 0.7uA - as per the datasheet, I think. However, I found that with a couple more code tweaks and grounding the SWDCLK, I would get into the nA region. This seems a bit out of spec to me and perhaps it’s just a measuring error, but it was repeatable and the board still happily sending data/heartbeat again each time it woke up. (It’s fluctuating around 1.6nA below - no sensors connected though, but it’s a start…)

    0_1555494689754_1.6nA Fluctuating Sleep Current - SWDCLK to GND - Pro Mini nRF52.JPG

    One other project in the back of my mind is using this board as the basis for a quadcopter, but that’ll probably have to wait until the summer holidays…!

  • @acb Nice! I have serious board envy. I really like that clip on programmer too.

  • @acb have you written a bootloader yourself, or found already available? Can you tell more about it and a board you using to connect nrf52 to FTDI?
    Nice work!

  • Well,in my case, I mounted and tried to fix bugs in my very first design. This is supposed to be a castelizable Sensebender compatible node, embedding NRF24L01+, LED, Temp/Humi/Press sensor, Memory, crypto, with most of the IO exposed. The updated design is online, but still work in progress. 0_1555517692648_IMG_20190417_180651748.jpg
    project on OpenHardware

  • @acb Wow. Awesome

  • My light sensor on the window. Will work as a slave device for the curtain controller.
    0_1555632724931_WhatsApp Image 2019-04-19 at 02.39.39.jpg

    Mysensors Light sensor (LUX) on nRF52832 | First HW&SW test – 01:46
    — Andrew EfektaSmartBox

  • Hardware Contributor

    New gateway going live and migrating slowly from Domoticz to Homeassistant. At least to try it.


  • @nagelc Thanks! The clip on programmer is one-part Adafruit’s FTDI “Fiddy” from here, and one-part SparkFun’s old (retired?) 3.3 or 5v selectable FTDI programmer with a custom 3D printed enclosure.

    I plan to modify the “Fiddy” design a bit as there were some elements of it that I’ve found a bit frustrating. However, YMMV. Gotta love pogo pins for programming though…

    Re: Board envy. Really? Well, if you like, I could do what I did on my last project - which was selling the leftovers. At the moment, I always make more than I need, for testing and some much needed practice with the smaller 0402s. Just send me a chat message if you (or anyone else?) are interested.

  • @monte Re: FTDI Boards & Bootloaders.

    I didn’t write the bootloader myself from scratch, but modified and combined various elements from Nordic’s SDK v11 example, SparkFun’s development version and Adafruit’s Feather version.

    It was quite a nice learning experience of hacking in bootloader land and dealing with event-driven architectures without any low level debugging skills (yet!) - that’s why I’m now trying to get into SWD/JTAG debugging to make things like this easier.

    I certainly don’t understand everything that’s going on, but “loosely” from what I can figure out, it uses Nordic’s proprietary SoftDevice (S132) combined with some custom bootloader code to boot into a predefined state, where it’ll wait for new “image” either over a serial or bluetooth connection.

    The new “image” can be either your regular sketch-type code (referred to as the “application”), a new SoftDevice (S212, S332, etc.) and/or even a new bootloader.

    Once the new “image” is received and validated by the (existing) bootloader, it is copied to replace the existing “image” parts where necessary and the chip is reset.

    Nordic’s pc-nrfutil command line utility handles interfacing with any standard FTDI board over a COM port (mine is an old SparkFun, but any should work) to perform the upload.

    In SDK11, there isn’t much in the way of safeguards, but in SDK15 there are things like cryptographic signing, custom initialization packets and protocol buffers, etc.

    I did have to make one tweak to the nrfutil Python code, to make it wait a little longer after opening the COM port before sending the DFU initialization packet. This might be unnecessary with optimized bootloader code, I don’t know, since the nRF52832 boots pretty quickly.

    I could go on, but I’m still learning myself, and so if you or anyone else has any other questions, comments, suggestions, etc., perhaps we better move them to a new discussion thread? (Just tag me in so I see it…)

    Thanks for your interest though!

  • Very nice @Fanfan!

    Love the power protections - those would have saved me a few nRF24s in the past!

    How have you found the ceramic antennas?

    I’ve been wondering whether to add pads to mine for experimenting...

  • Thanks @berkseo!

    Have been enjoying your work with nRF52 designs.

    Also on my list is trying the built-in capacitive touch capabilities of the chip.

    I can @ you if I get anywhere with it - might come in handy for your capacitive touch glass mini switch to save you a few components?

  • @acb Of course!!!, ttp 223 gives a reliable result, but if there is an opportunity to make a stable implementation based on the chip itself, then definitely it needs to be done. I would appreciate any help and advice.

  • @acb we can continue discussion in this thread, If you want: https://forum.mysensors.org/topic/6961/nrf5-action/

    So as I understand for now you are using native SDK and not using Arduino and mysensors? As far as I know arduino's core for nrf5 has no support for bootloaders, and mysensors conflicts even with softdevice being present on a chip. And it seems that sandeepmistry (author of the core) isn't going to invest his time into writing bootloader and can't use nordic's one because of license. I would like to have a bootloader solely for bluetooth OTA programming for projects beside mysensors. Maybe you could share your work, and/or write some kind of brief tutorial on where to start working on this subject maybe to avoid problems you have already solved? Anyway, great work from you, hope someday we will have mysensors on nrf52 with working OTA.

  • well this is my project , right now im using 2 arduino nano with ethernet shield to read 3 lines Voltage on a delta instalation , 3 current sensors of 300amps for a motor , and 1 water pressure ,
    all conected to a raspberry pi with domoticz

    but yesterday i decide to change all , instead of 2 uno i will use a pro mini with a nrf24
    so i desing two pcb


    some code

    #define MY_NODE_ID 100
    #define MY_DEBUG
    #define MY_RADIO_NRF24
    #include <SPI.h>
    #include <MySensors.h>  
    #define CHILD_ID_VOLT_1 1
    #define CHILD_ID_VOLT_2 2
    #define CHILD_ID_VOLT_3 3
    #define CHILD_ID_CURRENT_1 4
    #define CHILD_ID_CURRENT_2 5
    #define CHILD_ID_CURRENT_3 6
    #define CHILD_ID_PRESION 7
    #define VOLT_SENSOR_ANALOG_PIN_1 0
    #define VOLT_SENSOR_ANALOG_PIN_2 1
    #define VOLT_SENSOR_ANALOG_PIN_3 2
    #define PressPin      A6 
    unsigned long SLEEP_TIME = 20000; // Sleep time between reads (in milliseconds)
    MyMessage msg(CHILD_ID_VOLT_1, V_VOLTAGE);
    MyMessage msg2(CHILD_ID_VOLT_2, V_VOLTAGE);
    MyMessage msg3(CHILD_ID_VOLT_3, V_VOLTAGE);
    MyMessage msg4(CHILD_ID_CURRENT_1, V_CURRENT);
    MyMessage msg5(CHILD_ID_CURRENT_2, V_CURRENT);
    MyMessage msg6(CHILD_ID_CURRENT_3, V_CURRENT);
    MyMessage pressureMsg(CHILD_ID_PRESION, V_PRESSURE);
    float lastVolt1;
    float lastVolt2;
    float lastVolt3;
    float lastCurrent1;
    float lastCurrent2;
    float lastCurrent3;
    float lastPresion;
    int pressure = 0;
    float PSI = 0;
    float PSI_CAL = 2.0;            // Calibration of sensor
    int PSImsb = 0;
    int PSIr = 0;
    void before() {
    void presentation()
     sendSketchInfo("Multisensor", "1.7");  // Send the sketch version information to the gateway and Controller
     present(CHILD_ID_VOLT_1, S_MULTIMETER);   // Register this device as power sensor
     present(CHILD_ID_VOLT_2, S_MULTIMETER);   // Register this device as power sensor
     present(CHILD_ID_VOLT_3, S_MULTIMETER);   // Register this device as power sensor
     present(CHILD_ID_CURRENT_1, S_MULTIMETER);   // Register this device as power sensor
     present(CHILD_ID_CURRENT_2, S_MULTIMETER);   // Register this device as power sensor
     present(CHILD_ID_CURRENT_3, S_MULTIMETER);   // Register this device as power sensor
     present(CHILD_ID_PRESION, S_WATER);   // Register this device as power sensor
    void setup()  
    void loop()      
     int Voltaje1 = analogRead(A0);
     int Voltaje2 = analogRead(A1);
     int Voltaje3 = analogRead(A2);
     int Corriente1 = analogRead(A3);
     int Corriente2 = analogRead(A4);
     int Corriente3 = analogRead(A5);
     float VoltLevel1 = map(Voltaje1,0,1023,0,500);
     float VoltLevel2 = map(Voltaje2,0,1023,0,500);
     float VoltLevel3 = map(Voltaje3,0,1023,0,500);
     float CorrienteLevel1 = map(Corriente1,0,1023,0,200);
     float CorrienteLevel2 = map(Corriente2,0,1023,0,200);
     float CorrienteLevel3 = map(Corriente3,0,1023,0,200);
     Serial.print("Voltaje L1: ");
     Serial.print("Voltaje L2: ");
     Serial.print("Voltaje L3: ");
     Serial.print("Corriente L1: ");
     Serial.print("Corriente L2: ");
     Serial.print("Corriente L3: ");
     //sensor de voltaje
     if (VoltLevel1 != lastVolt1) {
         send(msg.set(VoltLevel1, 1));
         lastVolt1 = VoltLevel1;
       if (VoltLevel2 != lastVolt2) {
         send(msg2.set(VoltLevel2, 1));
         lastVolt2 = VoltLevel2;
       if (VoltLevel3 != lastVolt3) {
         send(msg3.set(VoltLevel3, 1));
         lastVolt3 = VoltLevel3;
    //sensor de corriente
       if (CorrienteLevel1 != lastCurrent1) {
         send(msg4.set(CorrienteLevel1, 1));
         lastCurrent1 = CorrienteLevel1;
         if (CorrienteLevel2 != lastCurrent2) {
         send(msg5.set(CorrienteLevel2, 1));
         lastCurrent2 = CorrienteLevel2;
         if (CorrienteLevel3 != lastCurrent3) {
         send(msg6.set(CorrienteLevel3, 1));
         lastCurrent3 = CorrienteLevel3;
    /* ************************************************ */
       pressure  = analogRead    (PressPin) ;        // junk read
    /* • Output: 0.5V – 4.5V linear voltage output. 0 psi outputs 0.5V, 50 psi outputs 2.5V, 100 psi outputs 4.5V 
       0   psi = .33v after scalling 5.0v to 3.3v
       50  psi = 1.65v
       100 psi = 2.97v
       3.3v/1024 = .0032266 volt per bit
       pressure  = analogRead    (PressPin) ;
       if (pressure < 106) pressure = 106;         // this is minimum of .5v
       PSI = (pressure - 106 ) * .1246;            // where did we get this?? was .119904
       PSI = PSI + PSI_CAL;                        // adjustment
       PSImsb = PSI * 100;
       PSIr = PSImsb % 100;
       send(pressureMsg.set(PSI, 2));            // Send water pressure to gateway
       Serial.print("Presion: ");
        // end of if (SLEEP_MODE || (cu

    havent tested with sensors yet

    but looks good so far
    0_1555866800921_Anotación 2019-04-21 121255.jpg

  • Today, the first sensors of the devices were soldered, the prototypes of which passed long-time tests. Eliminated children's sores. In matt black they are good 🙂
    1_1556060042292_IMG_20190424_014140.jpg 0_1556060042291_IMG_20190424_014129.jpg

  • Plugin Developer

    @berkseo whoa, time for a Kickstarter! They look great! Where did you have them made, and what do they cost?

    @fernando-alvarez-buylla Always nice to see the Aurora theme being used 🙂

  • And a few days later my pcb's arrived

    Now to test the next version

  • Plugin Developer

    How did you 'hack' it? All I see in the video is you changing a power wire?

  • @alowhum I replaced the manufacturer's software with my own.
    0_1556490111282_WhatsApp Image 2019-04-29 at 01.19.43.jpeg

    The device now works on the mysensors network

    1_1556490583713_photo_2019-04-27_15-12-06.jpg 0_1556490583712_photo_2019-04-07_15-31-44.jpg

  • Plugin Developer

    @berkseo very cool! How did you do that? Did you just have to connect the serial holes to an ST_LINK adapter or something similar? Was is difficult to open the device? And, most importantly: is your code available somewhere?

  • @alowhum Kickstarter? I'm not sure it's time 🙂 ..The cost of components is approximately $10. PCB made in China, soldered by myself.

  • @alowhum Soon I will publish codes and the description of process of dismantling and a firmware. But getting ahead.. it's very simple 🙂

  • Hardware Contributor

    Added two other (e)co2 sensors to my test-setup.
    Now 3 NDIR and 2 VOC under observation. 🙂

  • A family member gave me an old lamp with a fancy glass base. Well, I didn't like the lamp, but the base was nice, so I kept it in my basement for a few years. I found it again the other day and decided it needed to become a new type of lamp. I put a 150 LED strip (WS2812B) inside. I have an STM32 Blue Bill and RFM69HCW to run the light patterns and connect to MySensors.
    In Domoticz, I have it set up as a dimmer light, but the node just switches patterns depending on what the dimmer level is.
    At first, I wrapped the LED strip carefully around a tube that sits in the center of the glass jar, but it didn't look very good. Somehow just spiraling the strip in the bottom of the lamp has a much better effect.
    My wife even liked it, so maybe I will put some finishing touches on it and actually use it as a lamp : )

  • Well, Design of an home made electronic kit for my 10yo daughter to teach her by example. on 74HC595 (shift reg), 9 leds, 4 push buttons, some wrapping wire, ... We managed to build it, it works, with some bad contacts, but it works, she enjoyed the thing and the time spent together. Here is the schema and the pictures. I strongly invite parents to build it with their children, easy and fun. !
    1_1557074595586_59399854_1643957105747897_3582083341400145920_n.jpg 0_1557074595584_59168532_1643956979081243_7862945518123483136_n.jpg 0_1557074649088_Capture d’écran_2019-05-05_18-43-50.png

  • @fanfan
    Looks nice, and I love the idea that you spend time and knowledge to your kids 🙂
    but looking at the current budget it seems that you are above the rated current consumption for the 74HC595, just so you don't wonder in case it burns when several LEDs are ON at the same time

    Input clamp current, I IK (V I < 0 or V I > V CC ) ±20 mA
    Output clamp current, I OK (V O < 0 or V O > V CC ) ±20 mA
    Continuous output current, I O (V O = 0 to V CC ) ±35 mA
    Continuous current through V CC or GND ±70 mA

    Data from here:

  • Banned

    @dbemowsk I've been gambling with an Adafruit AudioFX board and cobbled together this annunciator. Eventually it will likely be a MySensors node to play alarms or different sounds. It is using a reasonably-priced transportable speaker to play the sounds. I were given it to work with my doorbell button node today.

  • Hardware Contributor

    Prototyping my netatmo replacement device. It has an led strip that can simulate a lighouse, a rainbow or a fireplace...
    (If not used only for fun, it should warn you, if there is too much CO2 in the air.)

  • Mod

    Today I have spent a few hours trying to eradicate the confusion between MySensors' different message acknowledgements. See https://github.com/mysensors/MySensors/issues/1103 and https://forum.mysensors.org/post/34263 for details.

     core/MyGatewayTransport.cpp                |  11 ++++++-----
     core/MyMessage.cpp                         |   8 +++++++-
     core/MyMessage.h                           |  31 ++++++++++++++++++------------
     core/MyOTALogging.cpp                      |   2 +-
     core/MyProtocol.cpp                        |  16 ++++++++--------
     core/MySensorsCore.cpp                     |  41 ++++++++++++++++++++-------------------
     core/MySensorsCore.h                       | 114 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-------------------------------------------
     core/MySigning.cpp                         |   4 ++--
     core/MySigning.h                           |   2 +-
     core/MyTransport.cpp                       |  20 +++++++++----------
     core/MyTransport.h                         |   4 ++--
     examples/SecureActuator/SecureActuator.ino |   2 +-
     12 files changed, 147 insertions(+), 108 deletions(-)

    I have also updated https://www.mysensors.org/download/sensor_api_20 to use echo instead of ack when describing the echo function. That page didn't have information on the return value for send, present, reqestTime, etc so I added info on the return value as well.

    Reference: https://github.com/mysensors/MySensors/pull/1292

    mfalkvidd created this issue in mysensors/MySensors

    closed Rename "soft ack" to "echo" #1103

  • Mod

    When doing the change above, i noticed that after I created https://github.com/mysensors/MySensors/issues/1107 the number of undocumented MySensors keywords has more than doubled!

    The plan was to let the MySensors butler check for missing keywords as soon as the few remaining keywords were documented. If I add the check on the existing code, the butler wouldn't allow any commits which would hinder development. But since no-one has documented the missing keywords in over a year, I decided to blacklist the missing keywords and add the check anyway. The new check will give developers a list of new missing keywords, if they add any, so they can be documented.

    Reference: https://github.com/mysensors/MySensors/pull/1293

    mfalkvidd created this issue in mysensors/MySensors

    open Document missing keywords #1107

  • Mod

    I've also submitted documentation updates for clarifying MY_RX_MESSAGE_BUFFER_FEATURE limitiation on esp8266 and renaming RadioSetting to TransportSetting for https://www.mysensors.org/apidocs/group__RadioSettingGrpPub.html


  • Today I have finished my d-diot board:

    d-diot board

    The board is part of the d-diot project (see my other post)

  • My 3V Node (Atmega328P 1MHz), embedded NRF24L01+ with ceramic antenna, ATSHA256, AT25DF512, BME208, LED, Battery monitoring, ICSP, FTDI, Castelizable, Breadboardable. 0_1560175339322_IMG_20190610_155632461.jpg

  • @fanfan nice! How is the signal compared to stock nrf24 modules? How much for antenna?

  • @monte A little bit less, but not a lot. I still need to improve the PCB (better castelization tracks, remove diodes, ...) and this should be ready to be copied/used.


Suggested Topics