The WORKBENCH part 1


#1055

x915

x916

cheap Adjustable PCB Holder


#1056

That’s strange it stopped at 1.25V looks like 1.25V shoud be fait enough to run with the DC/DC step up used, did you just tried to reset the board ? just curious because I had some transmitting below 1V battery

I added some 100uF caps to the output of this kind of DC/DC step up I made to get peak current fine. worth trying :wink:


#1057

I’d put a fresh battery in and it worked again… so the hardware is ok.
model 2 under test has a 3v battery and a better dc/dc converter :sunglasses:
should last more then a year

  • update

I put the empty battery back in and watched the application console…

zombie

it’s alive again… a zombie node … aaaaargh

@Charles … we had this integer overflow… luckily the nodes own frame counter started at zero and didn’t crash the running application … but could that be a problem in some situations (328P) ?

  • update 2

moved it to the other side of the room… signal is picked up again at ca. 13 km … so it did’n lose any rf power

zombie2

x917
The Transmitting Dead :flushed:

  • update 17 august 2018

now its ’ realy ’ dead :wink: @1.17 v

so it transmitted 83565 frames - 6864 hours - 290 days on single AA
hereby close this live test.


#1058

Ah, that PCB is still unused. :wink:

(Same here.)


(Phang Moh) #1059

The internal resistance of the battery must also be taken into consideration. During the burst transmission, more current is needed and hence a larger voltage drop within the battery itself is sometimes too much to sustain the output voltage. Every time, after a transmission and node going to sleep, the battery voltage will have some time to recover a bit (in Rob’s case where the battery is removed it is more obvious, I don’t think it would last that long after the restart). I did some fine tuning to the stability of the boost converter control loop to help to increase the stability during transmission and also lower down the minimum input voltage.


#1060

Hi Phang,

here you see the voltage drop during burst @ this moment … it’s not that much , about 55 mV ?

x918

RSzombie


(Phang Moh) #1061

The drop is probably across the reverse protection MOSFET resistance (RDSon) and battery internal resistance. Also MCU ADC is measuring the battery voltage after the reverse protection MOSFET.


#1062

yes but I’m meassuring ON the battery … (can’t reach the other side of the PCB now)
at the same time the console is open… so when the dc/dc quits, hence no lorapackets any more, I could see the battery voltage at that point ?

anyway… it’s no longer that important I think … just curiosity


(Sandgroper) #1063

Add a larger capacitor near the radio IC


#1064

tnx but off course … that’s not the point at this moment, we are trying to find out why and at what point exactly the dc/dc converter stopped yesterday , or maybe the rn2483 crashed or the 328p.


(Sandgroper) #1065

I must have missed something in the sequence you are following. I thought you were still trying with the old battery. If that was the case then I also think the internal resistance of the aged battery is the culprit.


#1066

x919

trying to add a gateway with help of @Charlesmagic script :sunglasses:


(Gry Kyo) #1067

I am ready to go with the same project but for Pi Zero W, Charles’ PCB and excellent instructions except that my RAK831 is still at large!


#1068

For a smaller gateway go RAK833.
But then @Charles first will have to solve a new challenge: make an RPi Zero adapter board for it. :wink:

capture%202018-06-21%2017%C2%B742%C2%B728


#1069

and @kersing won one so the softside is covered too :wink:
but he… they are really small !


(Tony Smith) #1071

Really impressed with these. Hope mine arrives today and along with my PCB and own designed high gain antenna hope to create a compact outdoor waterproof gateway with POE and Solar connections.


#1072

pics or it didn.t happen (joking :smile: )
would love to hear and see more from your project.

833devkit


(Jose Marcelino) #1073

I’ll just leave this here… :kissing_smiling_eyes:

f33368103773d62e54417c3e4c8e2355e985e589


#1074

@BoRRoZ Hacking suggestions for when you may get bored of your e-paper (and a real cool scope): :slightly_smiling_face:


#1075

lol… yes I’ve seen that vid… the scope I can’t afford in this life :sunglasses: