please these are my screen shots
please i am in a fix
I see one CRC_FAIL 100% message in your output. If the node is too close to the gateway (<3 meters), communication can be difficult.
Regarding the gateway no more online, is very difficult to tell something with no information. Is it on, is it connected to the Internet, etc. Try to restart it also.
so sorry boss for the late reply, i will try to move the node away from the gateway. and see if i can log on the pi screen. but how can i make the node frequencies to match those of my gateway?. because am building a voltage sensor and i want each sensor to work on a fixed frequency that corresponds to the various channels of the gateway.
that’s not the way to address your fellow TTN users imho 
anyway… please start with the LoRaWAN basics
please sir explain more. i have been on this now, my latest discovery is that my gateway recieves pakects on 867.7. while it has a paste that its a 915MHz. what do i do in this case
That’s not how LoRaWan works. Channels are dynamically and randomly chosen. End devices are distinguished by packet header, not by frequency.
i have been on this now, my latest discovery is that my gateway recieves pakects on 867.7. while it has a paste that its a 915MHz. what do i do in this case
The label would show the frequency for which the RF networks in the gateway were designed. The actual operating frequency is determined by the configuration files you use, you need to switch to the correct configuration files for your location. Hopefully those use a frequency matching that which your gateway was designed for, as trying to operate one on a frequency that the RF networks do not match will at best lead to poor range.
Thank you very much sir. For your reply. Now the sticker says 915Mhz. So after setting up the gateway, for about a week i could not recieve packets from the node. But today i just changed the frequency on the node to static 867.7MHZ and i started seeing packets on the gateway which means that maybe the sticker is wrong as this might be an 868Mhz RAK 831. Even though i have my global config to be US 915 bejng that am in Canada
That was exactly the WRONG thing to do.
It seems that you completely misread my email and did things exactly backwards.
Again, you need to use 915 MHz configuration files for your gateway.
And put your node back on 915 MHz randomly and fairly selecting channels from within the appropriate sub-band in accordance with the LoRaWAN spec.
915 MHz hardware will not work well on 868, and trying to use it that way is probably illegal in your location as those frequencies are allocated to a different purpose (probably mobile phones or police radios or something like that)