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Hi All,

For our project, we want to record voltage and current continuously for our DUT. I was able to twist some code in the current ranger so it stops auto shut off.

My main question now is that how do I convert the value display on the oscilloscope into the actual current value? From what I understand, we have to use ohm's law to do so. We are using the current ranger in the μA mode. What is the internal resistance of the current ranger?

Thank you,
Vincent
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Pi Gateway / Which stack firmware
« Last post by tunkmountainman on September 23, 2020, 05:56:01 PM »
 Hi I have a little IOT network that is working awesome...at least except for one metric that is failing to update on the dashboard. Checked everything bout 5 times now and I decided to ask for help. using minicom on the pi and it is receiving a 0 or a 1 from the gateway for a boolean, but the dashboard just shows an "On" all the time no matter if it is recieving a "O' or a "1". Have tried troubleshooting "Gateway.js" "Index.html".  Any help on where to find the file that does this conversion and I might be able to correct my programming.
  Thanks Dennis
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Update:

I'm not sure how to properly fix this in the current library without breaking existing code.

FYI I wrote my own RFM69 driver sometime ago (FreeRTOS on ESP32, non Arduino compatible) for a commercial project (closed source) that is event/message driven finite-state machine (FSM) with message queue and callbacks. Diagram of what I have:

It is efficient because it is non-bloking and allows for the uC to do other work (or sleep) as much as possible, but unfortunately not compatible with smaller uCs like the Atmega328p - this is why I used your library and noticed it can be improved.

So I guess I leave it here - anyone interested can apply the change mentioned above and get instant power consumption savings at the cost of broken Serial output.
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RF - Range - Antennas - RFM69 library / Re: RFM69 ATC Not working as expected
« Last post by DRBRODIE on September 22, 2020, 06:07:19 PM »
I guess I misunderstood.  I was just going by: the "RFM69_ATC: Automatic Transmission Control" article posted on November 11, 2015 which stated that "the node will start to progressively dial down power (assuming it starts transmitting at full power) with each packet sent, until the RSSI meets the target". Anyhow, I'm very happy with the Moteinos and their range and plan to use them throughout my home automation upgrade from a wi-fi based system. Thanks for responding so quickly!
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Low Power Techniques / Re: No restart after brown-out, using low power technique
« Last post by AgroMe on September 22, 2020, 03:17:28 PM »
Actually I've measured this and the cap charges fully; perhaps I should have mentioned this in the original post. Was actually wondering if it could be the radio (holding the interrupt perhaps??). I haven't had time to put a scope on it because I wanted to set-up like a lab way to test this instead of working directly on the grow with all the plants etc. So I decided to post the question just in case someone had seen this before or had any idea why it does not start after the V if fully charged. I'm pretty sure I tested reset manually at least once but IIRC it not always started the Atmel. That's why I started suspecting it could be the radio interrupt.

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Low Power Techniques / Re: No restart after brown-out, using low power technique
« Last post by Felix on September 22, 2020, 01:39:18 PM »
So what prevents it from starting after the voltage is above the brownout limit ???
I think it's probably a brownout :-)

Basically your cap recharges and it reaches just above BOD limit. Then the thing starts and draws more current than the cap can supply, dipping it below BOD again. So it's in this limbo state as it's trying to charge up, but the solar cell alone can't supply the current, and the cap is charged but not enough to sustain the startup current required.
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RF - Range - Antennas - RFM69 library / Re: RFM69 ATC Not working as expected
« Last post by Felix on September 22, 2020, 01:37:24 PM »
Please revisit my comment, I explained everything.

The fact that the RSSI stayed static and did not go down to the -90 target was the first thing that I did not expect. You can see that it stayed around -67 to -68.
That can be normal, if you consider what I explained, perhaps a misunderstanding (or incorrect expectation) how transmit power level and RSSI work.
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RF - Range - Antennas - RFM69 library / Re: RFM69 ATC Not working as expected
« Last post by DRBRODIE on September 22, 2020, 01:20:47 PM »
The fact that the RSSI stayed static and did not go down to the -90 target was the first thing that I did not expect. You can see that it stayed around -67 to -68. The second thing I didnít expect was the ďACK - nothingĒ response. I think you have explained the second one - thanks!
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RF - Range - Antennas - RFM69 library / Re: RFM69 ATC Not working as expected
« Last post by Felix on September 22, 2020, 01:06:22 PM »
Well it depends what you mean by "not as expected".

RSSI can be misleading because a strong signal is a higher number. So a -65dBm RSSI is many times stronger than -90. The -100db is where the "noise floor" starts. We want to be above that so the radio has a chance to still distinguish the useful signal from the noise. If your module is well within range, it might yield a very strong signal even at the lowest transmit power setting. At that point ATC can't make it transmit a weaker signal (ie "closer to the target" of -90 or whatever threshold).

So here's what you can expect.
If the RSSI reaches -90 (or whatever threshold is set) at a transmit power above 0, then ATC will keep it at that level to meet or exceed the RSSI threshold.
If the RSSI is already stronger than the threshold at power level 0, ATC can't ramp power down any more. It means you have a very strong signal at the lowest transmit power. Good thing, and ideal case.

The DS18B20 is a sleepy example, it transmits then sleeps. It does not actively listen for packets from the Gateway example. For that, use the Node example instead, which listens and does an sendACK() when a packet is randomly received from the gateway.
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RF - Range - Antennas - RFM69 library / RFM69 ATC Not working as expected? [explanation]
« Last post by DRBRODIE on September 22, 2020, 10:23:48 AM »
I have two Moteinos - one running the DS18B20 example from your github page without modification (except to change the node # to 2) using your coil antenna and the other running your Gateway example without any modification using an SMA foldable whip antenna.  Both sketches have the ATC enabled.
First, I do not see the RSSI dropping down to the -90 setpoint over time.  Second, on the third transmission I see "ACK...nothing" as shown below:

10:20:23.845 -> #[664][2] 1] F:81.05   [RX_RSSI:-68] - ACK sent.
10:20:29.017 -> #[665][2] 1] F:81.05   [RX_RSSI:-68] - ACK sent.
10:20:34.101 -> #[666][2] 1] F:81.05   [RX_RSSI:-67] - ACK sent. Pinging node 2 - ACK...nothing

Can you suggest what I need to do to correct this?
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