Hardware

Well it looks like that doesn't help :( Btw I am using the "normal" cheap 5V ones from ebay but soldered the 3.3V directly to teh small "H" pad at the side (worked without problems from a good power source). Any other ideas guys?

I have only tried 12V on the raw pin once and that immediately fried the Arduino AND the 1m 60 RGB LED light strip I had connected to one of the io pins.

@hek said: If you have an Uno around your can use that for programming the ProMini. http://www.instructables.com/id/Arduino-Pro-Mini-Stand-Make-It-Reusable/ http://www.instructables.com/id/Uploading-sketch-to-Arduino-Pro-Mini-using-Arduino/ It's weekend and I finally have the time to give this another chance and guess what? It works! I manage to upload the sketch to my Pro Mini and successfully created my first ever MySensors sensor! Thank you so much for that!

Yep, absolute maximum is 15V. http://www.advanced-monolithic.com/pdf/ds1117.pdf

@NeverDie Thanks i'd took the 1 led off but have taken d13 and the regulator off now. Sitting at around 2.7v although as i'm more so testing i'm reporting the temp as often as every 5mins if it changes.

Hello Epierre, I'm working in a proyect and i'm using MQ131 sensor, but I have a problem with the Arduino Code. I've seen the page (https://github.com/empierre/arduino/blob/master/AirQuality-Multiple_Gas_Sensor1_4.ino) but I have a problem because my sensor readings are 0. if you would be so kind, could you send me only the code of sensor MQ131 ??. Thank you very much!!

@kenci Hi Kenci, yeah i'd been in contact with him through ebay as i purchased it from him but sadly he wasn't able to assist too much as he said he was a hardware rather than software guy. I figured it out in the end, wasn't rocket science and just took a little digging which i'm not adverse too but just couldn't see it at first.

@Reza Do you have some references to this noise issue? Any papers, etc that proves the theory

@Samuel235 Nice job.. No need for additional grounding. The measuring circuit has the reference as a "virtual ground".

@AWI I agree that it would be nice if it was up to the controller to handle it, and then the units for different measurements sent to it were standardized on (like mm for distance). Also, it would be nice if the controller would allow selection of metric/imperial either by device, or sensor type. For example, I want my distance sensors in mm, but my temperatures in F.

The "Efficiency of Voltage Boosters" thread is full of useful info but has been sleeping for a year so this is an effort to bring it back to life again :-) I have built a few battery powered sensors based on the 328P-PU running at 8MHz as well as 1 MHz. Batteries used are common NiMH size AA + cheap Chinese 3.3V step-up converters. Both the processor and the radio are powered from the 3.3V converter which I understand can be a bad practice. Still I decided to try because I did not want to tamper with the fuses/bootloader at this stage and luckily I have so far not experienced any of the here described connectivity problems. More or less out of curiosity I made a few tests of this setup using different sizes of same brand electrolytic capacitors (nothing fancy, bought as a Velleman high-Q kit, labeled "made in Europe"). The results does not give more info than already available here but it helped me understand and hopefully can help others too. For the test setup a 10µF is soldered to the radio pins and I can add another in parallel through a socket. The unit tested is also equipped with both a 3.3 and a 5V step-up. A photo of the setup as well as a few screen dumps from an oscilloscope are attached as a pdf (hope it works). Readings are taken using a 8 MHz chip programmed as a motion sensor and while the sensor is at rest. 0_1462995658167_Tst.pdf Here is a short summary and a curve of same data: 10 µf dV 76 mV 10 + 22 µF dV 43 mV 10 + 47 µF dV 28 mV 10 + 100 µF dV 14 mV 10 + 220 µF dV 9 mV 10 + 470 µF dV 5 mV [image: 1462995740616-dv.jpg] A bigger capacitor of course lower the amplitude of the ripple (not unexpected :-)) and the rapidly falling curve shows that the current recommendation of 47 µF is a good choice. Adding more will lower the ripple but not at all proportionally. I am not experienced neither in building these battery powered sensors nor in measuring them why any comments/corrections will be appreciated.

I haven't tried it yet but this plugin for serial monitor over network looks nice https://github.com/esp8266/Arduino/issues/1360

Of course you can. Use voltage dividers to scale down voltages that you would like to measure if they are above your VCC. And you can also read the current from TP4056 charger board. Tap to Prog pin (pin 2) and measure its voltage. Here is the correlation between voltage and current: Ibat = (Vprog /Rprog) x 1200 Adapt the above code with your hardware values, current formula and measure away.

So easy ! I finally used directly BRD file and not GERBER. Thanks for the advice on DRU. The strange thing is that I tried with CAM job of OSH Park but the result was the same. But it's working with BRD so let's order my first board :) David.

Thanks! I definitely like V1's compact size (0.8in x 0.9in). Are there any mysensor nodes smaller than that, or is it currently the smallest? The Sensebender is also fairly compact (0.69in x 1.18in), although its effective thickness is much greater because of the way a traditional non-SMT NRF24L01+ gets stacked on it using a header.