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Post by keurslagerkurt on Feb 28, 2021 16:31:31 GMT
Hey all This weekend I've been testing some configurations with the ISD1820 chip. I noticed that when connecting my breadboard circuit to AE Modular 5V & ground, I get a voltage drop from 5V to about 3.8V. Measured on the AE. I tried both the 5V of the master module and Braedboard with the same results. I'm pretty sure that my circuit has no short circuits, and everything does work as expected. The ISD1820 is a fairly simple and small chip, so I can't imagine it drawing an awful lot of current. I also heard user sleeptotem in the discord having the same problem when connecting his Teensy to the AE Modular for power. Is this expected behaviour? Can I do something about it? Or should I not worry about it? (NB: accidentaly posted this in the wrong subforum here first, excuse me) |
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Post by robertlanger on Feb 28, 2021 19:02:06 GMT
Where did you take the +5V from? From the leftmost column of the red breadboard? Or from the 5V socket? This might be a difference.
Did you notice a changed behaviour of the AE system in general?
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Post by keurslagerkurt on Mar 1, 2021 8:02:14 GMT
Where did you take the +5V from? From the leftmost column of the red breadboard? Or from the 5V socket? This might be a difference. Did you notice a changed behaviour of the AE system in general? I did try the leftmost socket in the module. I have not tried the one on the red breadboard itself. I did not notice anything weird about the AE system and I played with for about An hour while the chip was connected. |
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Post by pt3r on Mar 1, 2021 11:50:32 GMT
Hey all This weekend I've been testing some configurations with the ISD1820 chip. I noticed that when connecting my breadboard circuit to AE Modular 5V & ground, I get a voltage drop from 5V to about 3.8V. Measured on the AE. I tried both the 5V of the master module and Braedboard with the same results. I'm pretty sure that my circuit has no short circuits, and everything does work as expected. The ISD1820 is a fairly simple and small chip, so I can't imagine it drawing an awful lot of current. I also heard user sleeptotem in the discord having the same problem when connecting his Teensy to the AE Modular for power. Is this expected behaviour? Can I do something about it? Or should I not worry about it? (NB: accidentaly posted this in the wrong subforum here first, excuse me) That's weird I didn't notice any trouble feeding my arduino pro micro via the power lines of the Braedboard. Are teensy's more power hungry? |
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Post by keurslagerkurt on Mar 16, 2021 11:41:28 GMT
Where did you take the +5V from? From the leftmost column of the red breadboard? Or from the 5V socket? This might be a difference. Did you notice a changed behaviour of the AE system in general? I was trying another breadboard circuit today, and i noticed that my signal led was flickering very weak. So I measured the 5V supply voltage and noticed that it dropped to 3.5V every time my transistor-led circuit got activated by a trigger. I used the 5V from the MASTER module & from the top right of the breadboard (female pin sockets). However, when I used the 5V supply on the Braedboard module itself, everything was perfectly fine, barely a drop noticeable. So i suppose the 5V on the braedboard module itself is buffered or buffered better than the other points? |
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XODES
New Member
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Post by XODES on Mar 16, 2021 14:59:56 GMT
The connections within breadboards can be far from 0 ohm, yet this is something one would normally notice on big ones.
You can verify pretty easily with your multimeter, and it would also be valid on the GND line, so basically you may end up with series resistors on your power rails, which would result on a lower local voltage.
Of course those measurements should be done while nothing is connected to your 5V or GND rails.
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Post by keurslagerkurt on Mar 16, 2021 22:23:12 GMT
The connections within breadboards can be far from 0 ohm, yet this is something one would normally notice on big ones.
You can verify pretty easily with your multimeter, and it would also be valid on the GND line, so basically you may end up with series resistors on your power rails, which would result on a lower local voltage.
Of course those measurements should be done while nothing is connected to your 5V or GND rails.
Well the weird thing is that the connections on the breadboard of the braedboard itself have less voltage drop than the connections straight from the sockets for me. So I suppose it has something to do with regulation/buffering |
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Post by beatstick on Mar 23, 2021 6:20:29 GMT
The 5V female socket on the MASTER module has a 100ohm impedance on it, so you can't source any significant current from it without the voltage dropping.
Most likely the impedance is there as a safety measure, since you're supposed to be able to plug anything into anything without stuff breaking. If the impedance were 0 then accidentally connecting it to ground would create a dead short and start melting stuff.
That means that socket is only good as a reference, not for powering stuff.
I don't have a BRAEDBOARD, but assume the situation is the same. The female sockets must be "safe", so there will be an impedance on the 5V sockets.
Of course it'd make no sense to do the same on the breadboard section itself, so sourcing 5V from there works as expected.
You can also source 5V from the bus headers and cables, if the need arises.
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Post by keurslagerkurt on Mar 23, 2021 7:40:03 GMT
The 5V female socket on the MASTER module has a 100ohm impedance on it, so you can't source any significant current from it without the voltage dropping.
Most likely the impedance is there as a safety measure, since you're supposed to be able to plug anything into anything without stuff breaking. If the impedance were 0 then accidentally connecting it to ground would create a dead short and start melting stuff.
That means that socket is only good as a reference, not for powering stuff.
I don't have a BRAEDBOARD, but assume the situation is the same. The female sockets must be "safe", so there will be an impedance on the 5V sockets.
Of course it'd make no sense to do the same on the breadboard section itself, so sourcing 5V from there works as expected.
You can also source 5V from the bus headers and cables, if the need arises.
Thanks for the thorough explanation, that makes a lot of sense indeed. Extra happy I got the Braedboard module now!  |
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Post by rodney on Apr 9, 2021 8:02:36 GMT
I'm curious now as I want to get the teensy 4 blinking and bleeping soon.
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Post by keurslagerkurt on Apr 9, 2021 8:10:40 GMT
I'm curious now as I want to get the teensy 4 blinking and bleeping soon.
I know always power my stuff from the breadboard section of the brAEdboard and this gives me a nice and clean 5V & Gnd! Haven't tried the buscable but i imagine that would give the same good result! |
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