This one works:
Look what I found on AliExpress
After seriously read the discussion by this thread and rak forum, we collect the suggestion and decide to optimize the rak811 tracker design as following:
Any more suggestions to RAK Wireless?
Arduino Compatible ?
Yes, that does work. I have one already. I’m looking for something with a shorter cable, so it’s not so bulky.
Hello, have you test with an another antenna ? I search an small active/passive antenna compatible RAK811 Tracker but I read about chip MAX-7Q is only with passive antenna. I’m not sure. I find only antenna with a long cable.
I’ve been getting excellent results with the passive GPS antenna that comes with the board. However, for LoRa, I have replaced the antenna with another one twice the size, giving me better antenna gain.
I have the same issue. Before getting a RAK811 I was playing with TheThingsUno + Ublox GPS. The RAK811 miss a lot of places that with the other setting I was able to connect. Did you solve the problem? I guess the problem comes with the LoRa antenna…
For those interested in the next gen of the RAK811 … https://www.rakwireless.com/en/beta-wistrio
I got mine RAK811-'s in two weeks ago from AliX not knowing there was a new ‘generation’ coming. But no hard feelings because my two units work excellent together with Cayenne.
It took only two days to get it working with all help I could find on the internet.
The new generation seems to be much more power efficient but be aware that it takes time to get a stable / reliable product both hardware/software. In that sense I do not have good experiences with the SODAQ tracker. I am looking forward to buy some discounted RAK811 trackers for my project.
My experiences with antenna that comes with the board and directly attached to the SMA is indeed good.
My larger antenna with cable 4 meters and magnetic foot does not perform better on the workbench. (cable loss)
The larger antenna will only benefit when the antenne height / freedom of sight is utilized.
THe transmit and receive antenna’s must be in the same plane/direction to make use of the antenna “gain” If this is not under control than it can make it worse.
Marcel / PE1MLT
An specified error of max +/-1 degree C in the 0-65 degree range is very accurate? Well it depends on the application of course. The Si7021 with max +/- 0.4 degree C error over -10 to 85 degree C is more accurate.
If you want accuracy, might as well go with the SHT31 with +/-0.2C accuracy (typical) over 0C to 85C - or the Si7021. BME280 is +/-0.5C at 25C and increases to +/-1C over 0C to 65C. For power consumption, the ranking from lowest to highest of average current consumption is SHT31 (1.7uA), Si7021 (2.3uA) and BME280 (3.7uA) where a temp/RH sample is taken every sec. In my experience in batch testing of sensors, Si7021 has a more accurate mean but larger standard deviation as compared to the BME280. In our products, the BME280 temp is LPF and typically gets better than +/-0.5C accuracy - which is acceptable in our application (higher importance is placed on RH and pressure accuracy than temp accuracy). The following link is to an interesting report but the sampling sets were small http://www.kandrsmith.org/RJS/Misc/Hygrometers/calib_many.html
Definitely coax losses at 915MHz, antenna height over average terrain, and proper polarization (vertical?) are all important to getting a LoRaWAN system working.
73 DE WA4OSH, Konrad
Need to be careful with the temp and humidity calculation library you use. The BME series has at least 9 internal calibration constants which are used to calculate temperature and humidity from the raw temp and humidity reading. If the library calculations are simplified then the error can be a few percent, particularly in the RH reading. I connect the sensors to a Raspberry Pi to get an accurate reading and then a Lora Node and compare the readings.
Could anyone point me to a recent “good” working library (git) , for my 811-tracker w. GPS (old model).
RAK also publish the open source project for rak811 as :https://github.com/RAKWireless/RAK811_LoRaNode
Finally we have RAK811 support in PlatformIO out of the box testing later, its been on and off this for months and months - one for 16kb and one for 32kb versions