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    NeverDie

    @NeverDie

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    Best posts made by NeverDie

    • RFM69HW temp-humidity node

      Not sure if others would have interest in this, but I'm designing a PCB for an easy-to-solder TH node. As presently conceived, it would have 3 surface mount components (an LED on the front and a resistor and capacitor on the back), plus a DIP atmega328p, a header to accept an inexpensive si7021 TH breakout board, an FTDI header, and an RFM69HW. The idea is that it would run at 8Mhz and be powered by two AA batteries, so it's sized to be compact but still easy to solder. The same thing could be achieved with wires and some of the other boards out there, but this might be a little tidier if a TH mote is what you want as either the starting point or the end-point.

      0_1474419735865_th_node.png
      PCB dimensions are 0.65x2.55 inches. i.e. it is narrower than a typical AA battery holder, but roughly the same length.

      The LED and resistor are optional, and you could forego the capacitor as well if you wanted a truly bare bones TH solution. However, the pads are there if you wanted to utilize them. Also, you could skip the si7021 BoB if you wanted just a generic mote.

      I had hoped that someone would make an easy to solder board like this for the RFM69HW, but I got tired of waiting and finally decided to just make my own.

      posted in My Project
      NeverDie
      NeverDie
    • RE: Everything nRF52840

      I found a good place to do range testing.... too bad I didn't bring the gear!0_1574455725203_20191122_134558.jpg

      posted in Hardware
      NeverDie
      NeverDie
    • RE: Where did everyone go?

      @OldSurferDude If I have a question about something I generally post the question. Sometimes someone will answer it, and all is good. But on those occasions where no one answers it to my satisfaction, and I later do figure it out myself, then I return and post the answer to my own question. I think if everyone followed this protocol, it would help. What I see across forums (not just mysensors, but just about all forums everywhere) is people who post questions with a "Thanks in Advance" attitude, but who never bother to close the loop if they do find the answer. Or they never confirm whether or not someone's suggestion worked or didn't work. The result is that when searching for an answer, one has to search through a lot of posts which don't contain any useful answers. So, I would encourage everyone to return and post answers to their own questions, if no one else already has, because in all likelihood someone else will have the same question in the future. I think that one small change might make a huge difference.

      posted in General Discussion
      NeverDie
      NeverDie
    • RE: Powering mote 24/7 using only a supercap and solar

      Good news! Last night I did some accelerated load testing on the supercap. First I charged it to 3.6v and then I hooked up an RFM69HW mote which woke up once a second to do 3 things: 1. check the voltage level, 2. turn on an LED for 1ms to simulate a sensor load, and 3. transmit a packet containing the voltage data using the RFM69HW.. Bottom line: 14,111 packets transmitted before running out of juice.

      Not bad for a first attempt. 🙂

      posted in My Project
      NeverDie
      NeverDie
    • RE: What did you build today (Pictures) ?

      Yesterday received the PCB. Today assembled for testing this battery-powered nRF52-based passive infrared motion detector:
      0_1511459187973_PIR_02.jpg

      posted in General Discussion
      NeverDie
      NeverDie
    • RE: What did you build today (Pictures) ?

      Made this 12 button keypad. Requires only one analog pin to read which button is pressed, and any button press can also wake an arduino from sleep:
      0_1517277256612_12keypad.jpg
      Consumes no power when no button is pressed.

      posted in General Discussion
      NeverDie
      NeverDie
    • Where did everyone go?

      For sure, the store shelves are pretty much overflowing with smart home products and IoT these days, much more than in the past. Is it just diffusion of attention, or do people just buy what they need now in complete systems or something? Or buy stuff that has phone apps instead of a hub? Or has Home Assistant taken over? Or Amazon Alexa? Not much in the way of new postings compared to the past. If anything, I thought there'd be more activity due to more and more IoT interest generally. If anything, it seems like Mysensors has a more robust and complete system now than in years past, and it's broad enough to include just about everything. What gives? Have off the shelf prices dropped so far that the economics no longer favor rolling-your-own or something? i.e. buy rather than build? Where's the new frontier? Is it now AI and system level stuff? I'm really curious. I mean, not all that long ago Google bought a thermostat company (Nest) for over a billion dollars. There's clearly been a sea change, and I'm just wondering what changed.

      posted in General Discussion
      NeverDie
      NeverDie
    • RE: Battery: pro mini @ 1mhz vs booster

      A pair of lithium AA primaries is hard to beat because:

      1. Unlike alkaline's, they don't leak.
      2. Have a look at the discharge curve: https://data.energizer.com/pdfs/l91.pdf By the time they drop to 2.4v, if not before, you'll want to replace them.
      3. Obviously much longer life, both shelf life (20 years!) and energy capacity.

      I think running 8Mhz from the internal RC is a no-brainer: wake up time is less than 4us. So, if your node wakes up often, you'll save a ton of energy over time.

      The best time to take your battery measurement is immediately after a Tx. That will give you the most conservative reading. Save that measurement in a variable and then send it in your next transmission. Switch on your ADC just before Tx and take your first ADC measurement during Tx, because you have to throw out the first measurement anyway. That way you can take a fresh (and valid) ADC measurement just after Tx before the voltage rebounds.

      Hope that helps!

      posted in Development
      NeverDie
      NeverDie
    • RE: Powering mote 24/7 using only a supercap and solar

      Here's the version that I most recently assembled:
      0_1486148795626_v021.jpg
      As you can see, the 15F supercap is now on the board itself. It works fine.

      I've since made a few refinements and have sent the new files off to be fabbed. The newest version of the PCB will measure roughly 22mm x 22mm.

      posted in My Project
      NeverDie
      NeverDie

    Latest posts made by NeverDie

    • RE: Best VOC sensor for detecting a wide range of VOC's?

      @eiten I haven't yet made any progress on finding a good VOC sensor, but along the way I did find out something interesting regarding CO2: namely, if you sleep with your bedroom door closed at night, then the odds are good that the CO2 levels rise to surprisingly high and unhealthy levels.

      The better CO2 sensors are factory calibrated and never again need recalibration for the life of the sensor (usually around 10 years or so), because they are used in HVAC systems to control fresh air intake to guarantee indoor air quality. As a for instance, here is one such CO2 sensor: https://www.digikey.com/en/products/detail/senseair/006-0-0008/15790694 At around $50 for just the sensor element itself, it's not exactly cheap, but then again, I'd say it's worth it, because who wants to be burdened by remembering to calibrate their CO2 sensors?

      Ideally, I'd like to find a sensitive VOC sensor that also will never require calibration.

      Nearly all, and maybe all, of the off-the-shelf IAQ montoring stuff that you might buy for, say, $300 or less seems to require periodic calibration. For that reason, this might be one of those occasions where build is rather than buy.

      posted in Hardware
      NeverDie
      NeverDie
    • Best VOC sensor for detecting a wide range of VOC's?

      I purchased a number of different consumer-ready off-the-shelf VOC monitors (priced in the range of $100-$300) from amazon for detecting the presence of VOCs (volatile organic compounds) in the air, and I'm finding that most of them detect very little of what's in the air, even if it's something I can plainly smell. 😞 What I want is a sensor (a canary in the coal mine) that will alert me as to whether there might be something in the air that I should be concerned about. From that point I would then have the somewhat arduous job of figuring out what it is. However, if I don't know it's there in the first place, then I'll never know to look further. So, I guess what I'm looking for is a sensor that's sensitive to a wide assortment of VOCs. Any recommendations?

      posted in Hardware
      NeverDie
      NeverDie
    • RE: CNC PCB milling

      Of possible interest: Here's a guy who is building an inexpensive open source ethernet controller for stepper motors:
      What happend to Ethersweep? Project Update! – 12:36
      — Neumi

      If you listen to the end, it's revealed that there is now generous funding available which allows people to do this kind of open-source development as a full time job, which is what he is now doing. For that reason, I think there's a good chance he will complete his project within the allowed 6 months., and so by the deadline it will likely be nicely polished.

      posted in General Discussion
      NeverDie
      NeverDie
    • RE: Awesome tip: run LinuxFX instead of Windows!

      @skywatch said in Awesome tip: run LinuxFX instead of Windows!:

      @NeverDie Thanks - Interestingly they show a free version on their site still. Did they revert due to bad publicity?

      https://www.linuxfx.org/

      I stopped following it, but I seem to recollect that the free version was noticeably missing things--otherwise, who'd buy the paid-for version? Anyway, its standing on Distro-watch has fallen considerably. It may seem unfair to niche distros, but I think it's generally better to stick with the more popular distros, unless you have good reason to choose otherwise.

      posted in General Discussion
      NeverDie
      NeverDie
    • RE: NewbiePCB sensors dying of old age

      Some humidity sensors are known to lose accuracy with age. For instance, the Si7021 is known to have this problem. If that matters to you, then the best choice is to pick sensors that have datasheets and which have specs as to their expected longevity or accuracy over time. Then buy from mouser/digikey to be certain you're getting the real thing rather than factory rejects or counterfeits.

      For extra insurance, I avoid electrolytic capacitors entirely whenever possible. I buy only 7XR rated ceramic capacitors that are overspec'd. The difference in price is small compared to a failure down the road.

      posted in General Discussion
      NeverDie
      NeverDie
    • RE: Awesome tip: run LinuxFX instead of Windows!

      @skywatch said in Awesome tip: run LinuxFX instead of Windows!:

      @NeverDie So how is it going for you? Have you tried USB devices with it? Did they work well? I am thinking of being able to run Win x64 SDR software on this but still wonder if it will work - Will try it out as soon as I can and report back. Meantime any hints or opinions you have would be good if you can share.

      Sometime after I made the original post the LinuxFX people decided they wanted to charge people money for their flavor of the OS. As near as I can tell, it kinda imploded after that. So, I settled on Linux Mint (Cinnamon version), and I'm happy with it. I still use Windows for programs that are only supported to run under windows, like Fusion360, rather than try to use wine to get it to run under Linux, but for everything else Linux Mint works great. Fast, stable, and without all the sluggishness you typically get (sooner or later) with Windows.

      posted in General Discussion
      NeverDie
      NeverDie
    • Using chatgpt to write code for the nrf52840....

      I haven't confirmed whether the offered solution will work or not, but it took only one second to generate, so on that basis alone I'm impressed.

      Anyone here using chatgpt for actual coding of any kind?

      By way of example, I gave this prompt:

      Without using zephyr, write a program for the nrf52840 to send a "Happy Birthday!" text message using the proprietary radio mode.
      

      and chatgpt's response was:

      To send a "Happy Birthday!" text message using the nRF52840 in proprietary radio mode without using the Zephyr RTOS, you can use Nordic Semiconductor's nRF5 SDK. Here's a basic example of how to create a custom radio communication program for the nRF52840. Please note that this code is a simplified example, and in a real-world scenario, you would implement error handling and more robust communication protocols.

      Transmitter (TX) Code:

      #include <stdint.h>
      #include <stdbool.h>
      #include "nrf.h"
      #include "nrf_gpio.h"
      
      #define RADIO_CHANNEL 76  // Choose a custom channel
      
      void radio_init(void) {
          NRF_RADIO->TXPOWER = RADIO_TXPOWER_TXPOWER_0dBm;
          NRF_RADIO->FREQUENCY = RADIO_CHANNEL;
          NRF_RADIO->MODE = RADIO_MODE_MODE_Nrf_2Mbit;
          NRF_RADIO->SHORTS = 0;
          NRF_RADIO->PCNF0 = (1 << RADIO_PCNF0_LFLEN_Pos);
          NRF_RADIO->PCNF1 = (1 << RADIO_PCNF1_WHITEEN_Pos) | (3 << RADIO_PCNF1_BALEN_Pos);
          NRF_RADIO->BASE0 = 0xE7E7E7E7;
          NRF_RADIO->BASE1 = 0x43434343;
          NRF_RADIO->PREFIX0 = 0x55443322;
          NRF_RADIO->TXADDRESS = 0x00;
          NRF_RADIO->RXADDRESSES = 0x01;
      }
      
      void radio_send(const uint8_t *data, uint8_t length) {
          NRF_RADIO->PACKETPTR = (uint32_t)data;
          NRF_RADIO->EVENTS_READY = 0;
          NRF_RADIO->EVENTS_END = 0;
      
          NRF_RADIO->TASKS_TXEN = 1;
          while (NRF_RADIO->EVENTS_READY == 0);
      
          NRF_RADIO->TASKS_START = 1;
      
          while (NRF_RADIO->EVENTS_END == 0);
          NRF_RADIO->EVENTS_END = 0;
      
          NRF_RADIO->TASKS_DISABLE = 1;
          while (NRF_RADIO->EVENTS_DISABLED == 0);
      }
      
      int main(void) {
          nrf_gpio_cfg_output(20); // LED on pin 20
      
          radio_init();
      
          while (1) {
              // Message to send
              uint8_t message[] = "Happy Birthday!";
              uint8_t message_len = sizeof(message) - 1; // Exclude null-terminator
      
              // Send the message
              radio_send(message, message_len);
      
              // Toggle an LED to indicate a transmission
              nrf_gpio_pin_toggle(20);
      
              // Delay between transmissions
              for (int i = 0; i < 1000000; i++) {
                  __NOP();
              }
          }
      }
      

      Receiver (RX) Code:

      #include <stdint.h>
      #include <stdbool.h>
      #include "nrf.h"
      #include "nrf_gpio.h"
      
      #define RADIO_CHANNEL 76  // Should match the transmitter's channel
      
      void radio_init(void) {
          NRF_RADIO->TXPOWER = RADIO_TXPOWER_TXPOWER_0dBm;
          NRF_RADIO->FREQUENCY = RADIO_CHANNEL;
          NRF_RADIO->MODE = RADIO_MODE_MODE_Nrf_2Mbit;
          NRF_RADIO->SHORTS = 0;
          NRF_RADIO->PCNF0 = (1 << RADIO_PCNF0_LFLEN_Pos);
          NRF_RADIO->PCNF1 = (1 << RADIO_PCNF1_WHITEEN_Pos) | (3 << RADIO_PCNF1_BALEN_Pos);
          NRF_RADIO->BASE0 = 0xE7E7E7E7;
          NRF_RADIO->BASE1 = 0x43434343;
          NRF_RADIO->PREFIX0 = 0x55443322;
          NRF_RADIO->TXADDRESS = 0x00;
          NRF_RADIO->RXADDRESSES = 0x01;
      }
      
      void radio_receive(uint8_t *data, uint8_t *length) {
          NRF_RADIO->PACKETPTR = (uint32_t)data;
          NRF_RADIO->EVENTS_READY = 0;
          NRF_RADIO->EVENTS_END = 0;
      
          NRF_RADIO->TASKS_RXEN = 1;
          while (NRF_RADIO->EVENTS_READY == 0);
      
          NRF_RADIO->TASKS_START = 1;
      
          while (NRF_RADIO->EVENTS_END == 0);
          NRF_RADIO->EVENTS_END = 0;
      
          NRF_RADIO->TASKS_DISABLE = 1;
          while (NRF_RADIO->EVENTS_DISABLED == 0);
      
          *length = NRF_RADIO->RXMATCH;
      }
      
      int main(void) {
          nrf_gpio_cfg_output(20); // LED on pin 20
      
          radio_init();
      
          while (1) {
              uint8_t message[16]; // Adjust the buffer size as needed
              uint8_t message_len = 0;
      
              // Receive a message
              radio_receive(message, &message_len);
      
              // Toggle an LED to indicate a reception
              nrf_gpio_pin_toggle(20);
      
              // Process the received message (e.g., print it)
              if (message_len > 0) {
                  message[message_len] = '\0'; // Null-terminate the received data
                  printf("Received: %s\n", message);
              }
          }
      }
      

      This code sets up a transmitter (TX) and receiver (RX) using the nRF52840's radio peripheral. The TX repeatedly sends the "Happy Birthday!" message, and the RX receives and prints any incoming messages. Make sure both devices are configured to use the same radio channel and have matching radio settings.

      Remember to adapt this code to your specific hardware setup and application requirements, and consider adding more robust error handling for a production-quality solution.

      posted in General Discussion
      NeverDie
      NeverDie
    • RE: Which one should i choose? PIR or microwave sensor

      Supposedly PIR doesn't work through glass (e.g. if looking for motion through a window), whereas I presume a microwave sensor might still work.

      posted in Hardware
      NeverDie
      NeverDie
    • RE: Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?

      ^^^This. Good point. Maybe do some testing with RadioLib to see whether or not you experience the same problem.

      posted in General Discussion
      NeverDie
      NeverDie
    • Looks as though the raspberry pi pico will provide 16-bit PWM duty-cycle resolution

      Contrast that 65535 step resolution to the 255 step duty-cycle resolution on Arduino's, and that is a big improvement for control of, say, a DIY DC-DC converter. For instance, if you want to build your own DIY solar MPPT boost converter (good luck finding one to buy in the commercial market. Probably 99%+ of those are step-down MPPT controllers, with only a rare bird being a step-up MPPT controller). The pi pico's are just $4 each at mouser and Adaruit ( https://www.adafruit.com/product/4864 ) for the genuine article, not some sketchy knock-off. Just thought I'd mention it, as I think most people aren't aware of it. I'm not sure whether or not a more stripped down version of the pi pico would consume significantly less current. If so, then it might be quite compelling: a fully formed pi pico board for $4 vs. an atmega328p chip alone for $3 (note: as a reference, these are present market prices on mouser).

      posted in General Discussion
      NeverDie
      NeverDie