Thanks for the info guys. When we move to our property we plan to homestead on I can see using these guys to create a whole network of sensors and other things throughout the property to keep track of a whole host of things, not just weather. I guess with these and a very low power version of an arduino type microcontroller I could really pare down the power budget and get away with a much smaller battery and solar panel.
On Monday, 30 January 2017 12:52:06 UTC-5, Bill Morrow wrote: > > I have a BMP180 for barometric pressure and a si7021 for temperature and > humidity connected to I2C on the Arduino Pro mini. > > The Arduino uses a nrf24L01 radio > <https://www.amazon.ca/Kuman-nRF24L01-Transceiver-Raspberry-Compatible/dp/B01C3YNGI8/ref=sr_1_1?ie=UTF8&qid=1485796501&sr=8-1&keywords=Kuman+10pcs+nRF24L01> > > and the RF24 Mesh <https://github.com/TMRh20/RF24Mesh> library to squawk > at the base station. I scraped off the onboard antenna and attached my > homemade 5 element Yagi. I think this has improved range quite a bit, but > gigahertz RF is voodoo, so who knows? I want to work on this. > > If I was doing it again, I might drop down to the sub-GHz range. For > example 434 MHz <https://github.com/LowPowerLab/RFM12B> would have much > better range. Those transceivers draw maybe 30 mA vs. 15 mA for nrf24l01. > But the radio is rarely active, so should not be an issue. > > I send a simple packet of data over RF24Mesh of 32 bytes. The nrf24l01 > radios are supposed to handle error correction and replies, so I don't do > anything for that sort of thing. That's the big advantage of something > sophisticated like XBee or nrf24, you don't have to do the low level error > handling yourself. > > On the base station side, I created a program which is the master on the > RF24Mesh, and publishes to the Mosquitto MQTT broker. It receives the 32 > byte packet and converts it into a single MQTT publication that looks like > this: > > TIME:0,AMBT: 7.23,BARP:1001.97,RHUM:70.92,HUMT: > 4.44,IRRA:12,BATV:974,PHOV:673,SYST:33.20,WIND: 0.0,WDIR: 0.0 > > My weewx wxMesh <https://github.com/morrowwm/weewxMQTT> driver subscribes > to the MQTT weather topic, reads the key:value pairs and . The nifty thing > about this approach is I can publish on the "weather" topic from multiple > stations, and wxMesh will merge them all together into loop packets. The > indoor station sends its data synchronously. > > On Monday, 30 January 2017 12:52:41 UTC-4, Robert Mantel wrote: >> >> I'm interested in the MQTT standard, didn't really know anything about >> it, but may migrate to that idea and skip the phant server step altogether, >> but using the fileparse extention with the jsonp query of the phant server >> just made things simple for me. >> >> As for the lower power radios I did consider using xbees, which I may do >> at some point, but I'm not sure if they will save me enough power to >> warrant the extra cost, we'll see how my experiment plays out. I guess I >> would have to migrate from my BME280 because it's either SPI or I2C and I >> haven't read anything about how to deliver that over an xbee radio >> connection. What radio's are you using? >> >> On Monday, 30 January 2017 10:50:28 UTC-5, Bill Morrow wrote: >>> >>> Very nice. I considered flower pots for the radiation shield also, but >>> then that wouldn't align with your snowflake theory, would it? >>> >>> I like both Sparkfun and Adafruit's ecosystem. Phant looks interesting. >>> I'm reading temperature and humidity in the house using an Adafruit Feather >>> Huzzah publishing over wifi to the MQTT broker. weewx subscribes to the >>> MQTT broker to get the data. Powered by a wall wart, but the Feather has >>> the capability of charging a battery. So in theory I could cut the cord >>> there too. >>> >>> My main goal is to harvest power from the PV cell on the top of the >>> lantern. It maxes out at about 25 mW at 3.2 volts. I should be able to >>> easily get 30 mAh every day, and a lot more than that on a sunny day. My >>> station averages about 25 mAh consumption per day. I've made no attempt to >>> cut power consumption on board, e.g there is a small power LED that is >>> always on. >>> >>> I'm working on a circuit provided by LInear Technologies: >>> http://cds.linear.com/docs/en/design-note/dn491.pdf, which boosts >>> almost any voltage to Li-ion charging levels. No success yet, mainly >>> because of the difficulty of working with parts with millimeter dimensions. >>> >>> You're dealing with a much higher power regime. But sounds like you have >>> some good power management strategies going. You might be able to reduce >>> your power needs by going to low power radios instead of wifi? >>> >>> On Monday, 30 January 2017 11:20:17 UTC-4, Robert Mantel wrote: >>>> >>>> Hey Bill, no problem. I can't provide pictures right now but will when >>>> I get home. I'm using an 8000 mAh battery I got from ebay (I may upgrade >>>> to a 12000 mAh), that is connected to an Adafruit Solar Lipo charger. I >>>> also bought a 6 volt solar panel from ebay or amazon, can't remember right >>>> now, but the adafruit charger works best with a 6v panel. The charger >>>> board has a connector for the battery, the solar panel and the load as >>>> well >>>> as an older mini-usb connector to charge the battery from an ac usb >>>> adapter >>>> if you just want to top up the battery when it's too low and it's really >>>> cloudy. You can also configure the rate of charge with the addition of a >>>> resistor to boost the charge rate to 1000 mA which is what I did. Most >>>> lipo's can only handle a charge rate of 1C (C being the capacity of the >>>> battery) so I'm well within the 8000 mAh that the battery could take >>>> charge >>>> wise. I'm currently experimenting with how many days I can go without >>>> intervention (hence the reason I may go with a larger 12000 mAh battery to >>>> get more days of autonomy out of the weather station). Ideally I would >>>> like it to run 24x7 without intervention. >>>> >>>> To save power I do with the Particle P1 redboard is that I have >>>> configured it to run in manual mode, meaning I control the wifi and cloud >>>> connections. Because I have a local phant server collecting the raw >>>> sensor >>>> data from the redboard I have no need to connect to the cloud and because >>>> I >>>> have it in manual mode I briefly turn on the wifi every 2 minutes to dump >>>> the sensor data to my phant server in the house. Wifi is by far the >>>> biggest power consumer so the more you can control that the better. I'm >>>> waiting for a 6 dBi wifi antenna to put on the particle P1 because I've >>>> noticed that sometimes the wifi doesn't connect where I have it placed >>>> inside my shed. All the sensors are outside the shed of course, but I >>>> wanted as much of the electronics sheltered from the elements for >>>> longevity >>>> sake. The only active electronics I have outside is the BME280 sensor >>>> inside my own home brew radiation shield I made out of flower pot trays. >>>> >>>> While I only post data to weewx every 2 minutes, the station is >>>> processing data continuously, so rather than feed for example the current >>>> wind direction and speed, I dump the average wind direction and speed over >>>> 2 minutes to weewx. In a previous iteration of my weather station I had >>>> it >>>> sleeping during each cycle but that proved to be a problem for getting >>>> accurate rain readings because if the station was asleep it would miss a >>>> bucket tip. So I went with a larger battery and then controlled the wifi, >>>> which saves a ton of power. The system has a rescue mode so that if the >>>> battery falls below 20% soc it will begin sleep cycles of 5 minutes so >>>> that >>>> the solar panel can pump all the power into the battery until it rises >>>> above that threshold and comes back online. So far so good, hasn't had to >>>> do that yet, but it may tonight because we've had quite a few overcast >>>> days >>>> lately. >>>> Let me know if you want more specifics and I'll help fill in the blanks. >>>> >>>> On Monday, 30 January 2017 09:59:03 UTC-5, Bill Morrow wrote: >>>>> >>>>> Robert, can you share any details on the solar powered Redboard? My >>>>> weather station is based on an Arduino Pro Mini, powered by an old Li-ion >>>>> camera battery. The weather station sleeps most of the time, waking up >>>>> briefly every 10 seconds or so to sample weather. I get about 2 weeks out >>>>> of the battery, then swap it. >>>>> >>>>> It's all housed inside an old solar garden lantern and a container >>>>> which originally held some delicious carrot ginger soup. It communicates >>>>> with a Raspberry Pi 1 in the house via nrf24L01 radios, using the >>>>> RF24Mesh >>>>> libraries. The radio is pretty power hungry, and the main reason for the >>>>> large sleep duty cycle. On the left of the case, you can see the antenna >>>>> pointing at the base station in our house. >>>>> >>>>> >>>>> <https://lh3.googleusercontent.com/-cf4BRy65O2w/WI9S_5UBXLI/AAAAAAAAEfY/YPV_pxfK36cppzaMq9XYPsbg0Lr7F0gKgCLcB/s1600/weather_lantern.jpg> >>>>> >>>>> The temperature sensor shield on the bottom is made from some sports >>>>> drink bottles. >>>>> >>>>> My main project these days is developing a circuit which will use the >>>>> small amount of power generated by the cell to keep the battery charged. >>>>> I've done some measuring, and it should be enough. I've gone down the >>>>> rabbit hole of tiny surface mount components, so making slow progress. >>>>> >>>>> Oh, and this is all supposed to be done under a zero cost budget! >>>>> >>>>> On Monday, 30 January 2017 10:33:58 UTC-4, Robert Mantel wrote: >>>>>> >>>>>> Seems like raspberry pi systems are like snowflakes...lol. I use a >>>>>> solar panel charged battery powered Particle P1 Redboard from Sparkfun >>>>>> that >>>>>> I have an I2C BME280 (temp/pressure/humidity/altitude) sensor, a >>>>>> rain/wind >>>>>> set from sparkfun as well. The redboard sends weather data over WiFi to >>>>>> my >>>>>> Phant server every two minutes, I have a cron job on my Pi that does a >>>>>> jsonp query to the phant server to retrieve the latest record and parse >>>>>> it >>>>>> out into a text file with the "* = *" pairs that fileparse wants. Then >>>>>> my >>>>>> weewx system running on my pi archives every 2 minutes. Not realtime, >>>>>> but >>>>>> good enough for my purposes. I also have steelseries gauges running as >>>>>> well. Been a great learning experience and everyone here has been very >>>>>> helpful. >>>>>> >>>>>> Many ways to skin the cat here. >>>>>> >>>>>> On Monday, 5 December 2016 04:32:46 UTC-5, Joaquin Lopez wrote: >>>>>>> >>>>>>> Hello, at the School we have this weather station >>>>>>> https://www.raspberrypi.org/education/weather-station/ >>>>>>> >>>>>>> It would be possible to configure the weewx system to be able to >>>>>>> receive the data from the different sensosrs of our weather estation? >>>>>>> >>>>>>> Thanks in davance! >>>>>>> >>>>>> -- You received this message because you are subscribed to the Google Groups "weewx-user" group. To unsubscribe from this group and stop receiving emails from it, send an email to weewx-user+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
