Hardware

I emailed Hi-Link about the HLK-PW01 power supplies that @rmh, @yannik-mündler and myself purchased. These are the power supplies with a removable bottom. I sent the following email to Sunny at Hi-Link (contact info: http://www.hlktech.net/contact.php). ++++ Hello, Are the two HLK-PM01s in the attached images genuine Hi-Link parts? A major difference is the part on the right has a bottom cover that is easily removable. I bought the part on the left from an Aliexpress seller in July 2018. The part on the right was bought from the same Aliexpress seller in May 2019. Thank you very much for your help. ++++ Here is Sunny's reply: ++++ Now all of our module are use new version . The one you bought on 2019 is the new version, the old version is not used yet. By the way,May I know you are the final user or the reseller? If you are worried about it,you can buy from our website www.hlktech.net or our Aliexpress store https://hlktech.aliexpress.com/store/211069 directly. ++++ I went to the Aliexpress page in their email and found the HLK-PM01 page. On that page they say: ++++ Recently,there are many fake module in the market,in order to Standardize the market environment,keep benifit for the customers,We,Hi-Link,changed our module to the new but more quality version,the back of new version is show as the following picture,currently,the old version and new version were sent random,please pay attention to that!thank you very much! ++++ They also show images of the previous version (which we are all familiar with) and the new version (with the removable bottom). So, it appears the HLK-PW01 power supplies with the removable bottom, from a reliable vendor, or directly from Hi-Link, are genuine Hi-Link power supplies. Below is my two images of the bottom of the two genuine power supplies (old on the left, new on the right). [image: 1560350467101-img_20190607_164006-resized.jpg] [image: 1560350493263-img_20190607_164018-resized.jpg]

Welcome to the MySensors forum. MySensors is a library you can use to create a wireless mesh network of sensors which communicate with a central point, such as your Raspberry Pi. You could attach an Arduino Nano to USB and talk to it via Serial. You could create a MySensors network, which you could also communicate to via an arduino+radio on your USB port. Then you could attach countless sensors. There is a ready-to-go sketch for the MH-Z19B.

Hi @Siddharth-Velappan The warmup time of the MH Z19b is 3 minutes. So 2 is probably fine, but you could probably do 3 just in case. Although 2 would save your more battery time. Do you mind explaining your setup a bit more? I would love to do something similar but I do not know where to get started with the PIC microcontroller!

I use a similar board like this (though without the battery) to show the weather forecast for today and traffic information for upcoming routes in our walk-in closet. So I don't have to check the forecast on my phone while dressing.

guess no odb port?

RF performance depends a lot on what's the setup antenna shape (coiled/meandered less efficient, or straigth one), orientation, radiation shape, size, tuning (inside final enclosure might be different, good to check rssis and adjust if needed), quality (lot of bad/untuned on some ebay/Ali shops) GND plane size, software settings the test environment etc for example, here I use 868mhz. I have a compact outdoor RFM69CW node with a simple homemade coiled "wire" antenna (RFM69CW has lower TX power, no power amplifier) sending well at 45-50m from the house, and the RFM69HCW gateway (with power amplifier) is indoor. One thick wall and some trees. Elevation of both ends/antennas is 1.5m, default software settings (for bitrate etc). But in direct line of sight, outdoor, there are also people reporting up to 1-2km range. Compared to MySensors on 2.4ghz, it can be easier to get reliable indoor link with subghz. Like in case you would already have others protocols on 2.4, with wifi and expanders, zigbee, ble, mysensors is not yet resilient to interferences and overlapping freq with these others protocols.. (no frequency hopping for example). It means, 2.4ghz needs more care, and depends on long term evolution of your network..

@bjacobse Granted that is what he has, but it's a lot more effort reducing a Nano to pro-mini compared to the cost of a getting a pro-mini to begin surgery to start with... We all have devices bought with good intention gathering dust as we learn.... ;) One of these days will get a Nano to play with, but had dismissed it for battery applications from the start of this adventure and have seen no reason to reconsider that conclusion since.. For testbed or PSU applications, fine, but for battery applications?... As the Limerick man advised the driver seeking directions to Dublin, " I wouldn't start from here" :)

@arden you can found on this blog some sensors using NRF24L01 and Attiny84 http://domotique-diy.over-blog.com I think migrate mysensors to this project

@rpunkt if 3ma is your current draw while sleeping, you will quickly drain any battery or supercap. The "mini boost buck dc board" itself has a no-load current of 1.77mA. Might look here for low-power libraries and design considerations: http://www.home-automation-community.com/arduino-low-power-how-to-run-atmega328p-for-a-year-on-coin-cell-battery/ https://github.com/rocketscream/Low-Power

great work @arden, thanks for reporting back!

@arden nice work! Gateway can be on the same pi as the controller. Many people use that configuration. Personally I use Domoticz, because it is very easy to get started with. I think Hass has more features, so in the long run Hass might be a better choice.

Basically you have 2 options: You are present to watch when the port goes down something expensive like this: https://duckduckgo.com/?q=Safety+Light+Curtains&t=canonical&iar=images&iax=images&ia=images

3mA sleep current is very high, you should probably set a goal for a few hundred uA maximum. I would suggest determining what is causing high sleep current consumption. This is theoretically possible with atmega328p as well as nrf24l01, should be able to accomplish this if using proper sleep and/or standby modes for each. Another thing to look at is the hardware your boards are using. One notorious culprit for high sleep current is AMS1117 voltage regulator, which has very sad ~4mA quiescent current - not appropriate for power-saving/battery nodes - but far to common on boards you will find (like clone of pro-minis, etc). (There are several other 3.3v LDOs with much better Iq - https://ethercalc.org/500ma-ldos) This might also have some good ideas as a place to start as well: http://www.home-automation-community.com/arduino-low-power-how-to-run-atmega328p-for-a-year-on-coin-cell-battery/

@sharpy Theoretically it can be done for the processor for sure, but you will hit problems with radio which is less amenable to low voltage. You only really need remove the power LED for the pro-mini as that runs continuously, removing the VR requires external voltage source and control, tinkering with the processor speed and fuses (google here if unfamiliar) enables the processor to run down to very low volts with restricted performance, all well documented here and elsewhere, but as previously commented, radio may prove the greater problem. ;) My selected 16MHz 3.3v Arduinos stretched available performance to the limits, and no regrets, 100% reliable all the way down to sucking the batteries dry. You may be better skilled than I to try, info aplenty here to assist from those who've been there and done that...

@eeichinger Yes an old thread, but still useful. well if you plan to run on a low voltage, you must disable BOD, else per default the 328 will switch off at 2,7V. And then you need to run 1 at MHz

@yveaux thank you for letting me know about this great project! The thread is also very useful. I managed to find a relatively quiet range in channels.