Protection for USB

[jasonr2231]

Is there any way to protect my computer USB port from stupidity?
Ethernet is possible but I don't know how well that is isolated (and I am out of router ports and would have to put my 24 port switch back online).

I somehow let all the smoke out of my Arduino Mega 250 last night (final perm connections on project) and it seemed to upset the USB port in my Hometroller S6 Pro. After all the smoke came out, I noticed I could not control my Z-Wave in HS3...could see status but could not control. Panic ensued. Z-Stick was on adjacent USB port. Moved to other end of Hometroller and all is ok. Once i get my Hometroller looked at and have the guts to go back to project, I would like to protect myself from myself. Still haven't found what I did wrong.....maybe a few days of cooling off and I'll find it.

[randy]

Is there any way to protect my computer USB port from stupidity?
Ethernet is possible but I don't know how well that is isolated (and I am out of router ports and would have to put my 24 port switch back online).

I somehow let all the smoke out of my Arduino Mega 250 last night (final perm connections on project) and it seemed to upset the USB port in my Hometroller S6 Pro. After all the smoke came out, I noticed I could not control my Z-Wave in HS3...could see status but could not control. Panic ensued. Z-Stick was on adjacent USB port. Moved to other end of Hometroller and all is ok. Once i get my Hometroller looked at and have the guts to go back to project, I would like to protect myself from myself. Still haven't found what I did wrong.....maybe a few days of cooling off and I'll find it.

The only thing that comes to mind is externally powering the Mega AND connecting it to USB. This is the only way I can think of that could damage the controllers USB port. The USB power fro9m your S6 should be adequate to run the Mega.

[jasonr2231]

Dual connection

Sorry I'm new at this so my response may seem odd.....I have had the USB AND power supply hooked up to it for several weeks without issue. But, I could see how removing the power supply may help. I am assuming I applied voltage to a Vin pin as I have seen that can go back to controller (although I can't seem to find where I may have) and if that's the case, I believe I can still damage my USB port in controller. I am using one-wire and several analog inputs (12V to 3.8V through voltage dividers). I did have the one-wire Vin and Signal reversed for a few minutes (not as bad as Vin Gnd a few weeks ago). So I appreciate the input of removing the dual power source but I am still looking to isolate the USB controller from USB on Arduino. Was thinking maybe a USB hub, hoping the hub would take the damage if it occurred. Was also hoping wifi was a possibility. Searching the forum for that, now.

[randy]

Sorry I'm new at this so my response may seem odd.....I have had the USB AND power supply hooked up to it for several weeks without issue. But, I could see how removing the power supply may help. I am assuming I applied voltage to a Vin pin as I have seen that can go back to controller (although I can't seem to find where I may have) and if that's the case, I believe I can still damage my USB port in controller. I am using one-wire and several analog inputs (12V to 3.8V through voltage dividers). I did have the one-wire Vin and Signal reversed for a few minutes (not as bad as Vin Gnd a few weeks ago). So I appreciate the input of removing the dual power source but I am still looking to isolate the USB controller from USB on Arduino. Was thinking maybe a USB hub, hoping the hub would take the damage if it occurred. Was also hoping wifi was a possibility. Searching the forum for that, now.

A powered hub will give you isolation and is an especially good idea while breadboarding. Be especially careful with voltages on analog inputs. Excess voltage can really damage the Arduino analog inputs. I protect mine with 5.1V zener diodes for safety.

[jasonr2231]

Thanks

I was kind of thinking my issue may have been the Vin. My 12VDC is a trigger output from my Nuvo zone control. Wonder if I had a spike that exceeded 5.1VDC through the voltage divider. I'll start with a USB hub. Is the Zener diode just in series on the Vin wire or parallel tied to ground?

[zwolfpack]

Check this out. There are lots of good introductory tutorials out there.

https://www.digikey.com/en/articles/...al-electronics

[randy]

I was kind of thinking my issue may have been the Vin. My 12VDC is a trigger output from my Nuvo zone control. Wonder if I had a spike that exceeded 5.1VDC through the voltage divider. I'll start with a USB hub. Is the Zener diode just in series on the Vin wire or parallel tied to ground?

From the analog input pin to ground. I like to use the Velleman I/O shield.



It already has the zener diodes



It also provides 6 relay outputs and 6 digital inputs with LED indicators. It will work as is without an Ethernet shield, but requires some modification to work with an Ethernet shield.

[logbuilder]

You could go with a nodeMCU and go wireless and ditch the USB port altogether (other than for loading new programs).

[enigmatheatre]

(other than for loading new programs).

You don't even need it for that as the latest betas have OTA upload to get the sketch to the board with WiFi.

Greig.

Sent from my SM-G950F using Tapatalk

[jasonr2231]

[randy]

I have 4 Arduino Megas and 3 NodeMCU boards in production. My system remains 100% reliable. The NodeMCU boards are reliably connected 100% of the time. The only thing I need the Megas for is their support of OneWire. I have one analog input for testing, but otherwise I could go with all NodeMCU boards but for OneWire. The beauty of the Mega is the sheer number of inputs and outputs, which serves me well in two locations.

[jasonr2231]

Yea...I guess i'm not quite up to speed yet. I thought the nodeMCU was a way to connect the mega via wifi. Still more research for me to do. It DOES seem like a good way to go but I have that one one-wire network which it appears is going to leave me wired to USB. Is there a product that will work with one-wire AND is wifi?

[randy]

Yea...I guess i'm not quite up to speed yet. I thought the nodeMCU was a way to connect the mega via wifi. Still more research for me to do. It DOES seem like a good way to go but I have that one one-wire network which it appears is going to leave me wired to USB. Is there a product that will work with one-wire AND is wifi?

There is not currently an Arduino solution that does. For the bulk of my OneWire devices, I use the EDS OWServer. They will handle at least 21 OneWire devices and can be connected by WiFi. They support sensor loops of up to 1000 feet and there are three buffered inputs, each can support its own loop. I use several, connected by Ethernet, with loops around the house for sensors. I wrote about these and other items in this thread. My system has evolved considerably in 4 years, but I posted some updates as I made some changes. I have changed things a little since my last post in 2016. I'll try to update it at some point. The thread may give you some ideas.

[jasonr2231]