The WORKBENCH part 2

Jeff-UK · October 10, 2018, 10:10am

I believe the SPI bus on SX1301 is probably system throughput limiter and is ~2Mb/s IIRC so plenty of headroom on your system with >5Mbps though updates/upgrades of s/w and new downloads obviously wont be fast! Not sure if you are also taking a hit on latency (RX1/2 window timing?) but probably not much worse than using BBand over cellualr as backhaul? Still I recall 1st broadband connection was a turquoise Alcatel USB ‘Manta Ray’ modem serving just 512kbps on DSL so its a 1st world problem! How spoilt we are…

TonySmith · October 10, 2018, 10:28am

Oh Wow!! I thought my 10Mbps was on the slow side and was looking at other SPI based Ethernet controllers. If your 5Mbps works fine with a RAK831/833 then I won’t bother going any faster. Developing a simple POE power supply combined with a Ethernet controller for a compact RaspiZero / RAK833 gateway.

BoRRoZ · October 10, 2018, 10:35am

later today I test a bit more… I measured this without the forwarder running

BoRRoZ · October 10, 2018, 10:39am

Jeff (and other TTN’ers) a suggestion… upload a profile picture (in the console)

profilepic

that way it’s easier to recognise people imediate on the forum

Amedee · October 10, 2018, 11:54am

FYI, this is what I have for a RPi Zero gateway (Running my Docker containers):

Load and CPU usage is pretty much OK, so going from 1GHz to 700MHz (A or B+) should be OK.

Memory is not too bad, we stay around 110/120MB for User+Cache, so it might be doable with an a A 1st generation.
Something to test…
(I have the whole line of ‘B’ models here, but no ‘A’)

BoRRoZ · October 10, 2018, 1:50pm

x1096

For better photos too … cool !

update… this one is working so I have a back up now

working

and I just ordered a few more of these SD cards, in China, for half the price

one week laturrrrrrrrrrrrrrrr …

x1109

that’s funny… the speed is 2 mb/s less on the packaging

Jeff-UK · October 10, 2018, 8:47pm

Have you seen the price of a new camera/PC? Wouldnt dare capture this mug-shot!

Besides a little (semi)anon helps - will find a good symbol instead…looks like a rastaman with dreads & red/yellow/green Hat bands already taken

TonySmith · October 11, 2018, 3:34am

I have always used this brand and model and never had a problem. Even pull the power to turn off, no clean shutdown and still not had a problem.

GryKyo · October 11, 2018, 10:45am

I understand this is chancing to fate and not how it is supposed to work, but yesterday I was replying to a deep-sleeping node within the same RX window as an “interrupt-wake-TX” event. Hope that makes sense?

I had an instance of Node-RED use a TTN RX event to then trigger code in a Node-RED function to check a global variable and decide to reply with a packet or not. In the event of a reply being prepared it was being scheduled and transmitted during the standard RX window from the original interrupt/wake.

I understand this is the result of super low latency on the whole round trip but does show how fast the TTN back end and Node-RED/MQTT is in real life!

I should put up a little video…

BoRRoZ · October 11, 2018, 10:51am

yes that would be nice… or a little LAB story how exactly you did this
’

GryKyo · October 11, 2018, 11:48am

I do indeed plan to. Interesting little project for home engineer hackers

Raspberry Pi physically embedded in my home alarm control panel with digital GPIO inputs to ascertain if the alarm is armed or alarming. One other GPIO to drive the “Fire Alarm” input to my home alarm. Interfacing is done with 2N2222 transistors and a few resistors, very simple.

TTN node device will monitor the door of my shed.
It will wake and indicate any change in state.
Node-RED on the Raspberry Pi will decide if the alarm is armed
Node-RED on the Raspberry Pi will trip the house alarm if appropriate
TTN node device will drive a solar/battery piezo siren in the shed
TTN node device will beacon the Pi to know when the event is over

System already works (for 5 years or more) with WiFi & MQTT but power use on the solar/battery close to a tree is misery to manage!

BoRRoZ · October 12, 2018, 8:53am

PiZero gateway works with that slow dongle… no probs sofar

x1097

pe1mew · October 12, 2018, 10:08am

RSSI of -48 dBi? Seems a mistake to me when RSSI is in dB-isotrope. It highly unlikely that you reference RSSI to an isotrope. “dBm” is more apropertiate IMHO