T4.1 Ethernet board

[drjohnsmith]

First up, great new board the 4.1

I know your going to get a lot of this sort of thing.

The Ethernet board, if the 6 pins on the Ethernet board were off set to one side, then it looks like the Ethernet board could be soldered via pins direct to the 4.1, no need for cable, unless you wanted one,

Removes worry about the EM problems with the cable, let alone the cost of cable and connectors,

now if the Ethernet card was wide enough that there were side pins that soldered down to the side pins on the 4.1 as well, may be 4 of them, then a strong enough for testing unit would be able to be made,

 

[MorganS]

Then you get one of these... https://www.mouser.com/ProductDetail/Bel-Magnetic-Solutions/0820-1X1T-00-F?qs=sGAEpiMZZMvQhAhQbXdbBhrEwE4Ds1jHaYqXdbGAlwg%3D

...which is a combined USB and Ethernet socket so you could connect the USB pins too!.

The real problem with a direct-soldered board like this is the Ethernet socket is the same width as the Teensy, so the pins clash. You have to mount the Ethernet jack at an offset, which may put it forward or behind the Teensy's USB socket or float above it on long pins. What is your preference?

 

[Logs]

Would anybody has an opinion if HR911105A Magjack could have the same performance as Wiznet RB1-125BAG1A suggested by Paul for T4.1 ethernet interface ?

 

[crazy-logic]

Is it possible to patch pins directly into the 4.1 ie, a rj45 (cabled male) jack directly to the 4.1 then straight into a switch without a magjack? Thinking for testing on bench/lab

 

[defragster]

Is it possible to patch pins directly into the 4.1 ie, a rj45 (cabled male) jack directly to the 4.1 then straight into a switch without a magjack? Thinking for testing on bench/lab

No. The magjack provides significant function in voltage reduction and signal presentation.

 

[Robin_B]

I just soldered up a minimal connector using just the one required 0.1uF capacitor on the magjack. It works beautifully and the UDP speed tests I've done show speeds over 90mbit/s.

 

[b2020]

FYI - related thread

https://forum.pjrc.com/threads/60851-T4-1-ethernet-and-usb-host-pin-alignments-dimensions

 

[KillerBug]

This may be the wrong place to ask this, but it is the first remotely relevant google result so I'll ask here. There are 5 unlabeled pins between the reset button and the microSD slot. There is another next to the USB connector, plus another 21 unlabeled test points, two of which are connected by a trace that appears designed to be cut easily. Is there a full pinout of the 4.1 that at least covers the unlabeled TH pins and maybe those two pads connected with the cut-friendly trace? I'd trace them myself but the store is sold out...and I'm designing the board that my 4.1 will go into once it's not sold out. If those are something related to the microSD slot, I want to add a remote one so all the connectors can be on one side of the board.

 

[MichaelMeissner]

The 5 pins between the reset button and the micro-SD slot are the same pins in the back of the Teensy 4.0 (between outer row pins 13 and 12).

On the Teensy 4.1, including the two outer pins, these are:

• Outer row pin 38;
• On/off pin;
• Program pin;
• Ground pin;
• 3.3v pin;
• Vbat pin to power the real time clock with a 3v coin battery (connecting also to a ground pin); (and)
• Outer row pin 27.

The single inner pin next to the ground pin in between VIN and 3.3v is the Vusb pin. There is a pad underneath the Teensy that connects VIN and Vusb. You can cut this pad if you need to power the Teensy without using the USB connection. See the back of the other Teensy cards for some more information about it.

Next to pins 20 and 21 are 6 pins (3x2 layout) at 2mm pitch that connect to the Teensy 4.1 ethernet.

On the other side there are 5 pins inside the Teensy. These 5 pins bring out the USB host support. The pins are in the same order as the same pins on the Teensy 3.6 (i.e. going from the USB to the back, the order of the pins is VIN (i.e. 5v), D-, D+, and two ground pins, that are same layout as common USB cables in PCs).

Underneath the micro-Sd card reader are two sets of 8 solder pads. The first 8 pads (next to the edge) are for attaching a psram memory chip. The next 8 pads are for attaching either a second psram memory chip or a non-volatile flash memory chip. The two sets of pads share 7 of the 8 pins (the unique pin in both cases acts as the CS pin). These memory pads are on a FLEXSPI controller.

 

[KillerBug]

Great! Thank you so much!

 

[mah]

Is this right?

 

[PaulStoffregen]

That looks good, with the caveat that I know nothing about SI-46001-F other than the pin names you used.

Teensy 4.1 has a 150 ohm resistor, so adding 250 more is probably going to give a very weakly lit LED.

 

[PaulStoffregen]

We now have a kit available for the ethernet connection.

https://www.pjrc.com/store/ethernet_kit.html

Here's the schematic from that page.

The magjack datasheet is also linked from that page. Hopefully this helps?

 

[MorganS]

No. Don't connect 3.3V to the center taps. Just the capacitor(s)

 

[PaulStoffregen]

Oh, opps, I missed the 3.3V power! MorganS is right, don't use 3.3V on the transformer pins.

Many other ethernet PHY chips need this. But the DP83825 chip we use on Teensy 4.1 does NOT use 3.3V connected to the transformer.

 

[mah]

We now have a kit available for the ethernet connection.

https://www.pjrc.com/store/ethernet_kit.html

Here's the schematic from that page.

The magjack datasheet is also linked from that page. Hopefully this helps?

Yeah, thanks, could not find a schematic so i looked at other schematics. gonna remove the 3.3v, and the resistor.
Dont know much about the SI-46001-F either, just picked it because i needed a vertical jack, and it said "magjack" in the datasheet..
If you know any vertical connectors let me know.

 

[GyroGearloose]

For a prove of concept I would like to communicate between two µControllers directly via Ethernet UDP protocol.
I got 2 Teensy 4.1 but unfortunately over here the Ethernetkit is not yet available.
I cut a Ethernet cable in half an connected the RJ45 with a coupler. (The little switch is for the crossover.)
Is this an acceptable solution or am I missing anything? I'm wondering because the Ethernet Socket in the kit is a inductive coupled device and the socket on my old Arduino Ethernet Shield is connected directly.
The LED is via a 1K Resistor to Gnd; there is no Capacitor.
Is this a good alternative compared with the Ethernetkit? No. One should only use it if there is nothing else available because everytime the cable is plugged in or out the soldered wires are moved and will pretty soon break off.

 

[Eity1985]

Yes It good cost reducing plan for Internet service and other.

 

[bluelaser]

We now have a kit available for the ethernet connection.

https://www.pjrc.com/store/ethernet_kit.html

Here's the schematic from that page.

The magjack datasheet is also linked from that page. Hopefully this helps?

This is not correct according to datasheet or evaluation board produced by PHY vendor. You have the center taps tied together. Each needs at least a 0.1uF cap to ground. The PHY does not drive it. In the data sheet each center tap has 0.1uF and 1uF. However in the evaluation board it is just two 0.1uFs per center tap. The analog ground stuff is just for EMI/ESD suppression. (Usually optional unless require for compliance.)

Page 3:
https://www.ti.com/lit/df/snlr041a/...mode-df-pf-null-wwe%26DCM%3Dyes%26distId%3D10
Page 93:
https://www.ti.com/lit/ds/symlink/dp83825i.pdf

Note you have links to both versions on the website. I noticed two different links to magnetics, part lists, and OSH park board.

 

[bluelaser]

Is it possible to patch pins directly into the 4.1 ie, a rj45 (cabled male) jack directly to the 4.1 then straight into a switch without a magjack? Thinking for testing on bench/lab

No, you need the magnetics inside the MagJack. However if the magnetics were on the board maybe.

 

[bluelaser]

For a prove of concept I would like to communicate between two µControllers directly via Ethernet UDP protocol.
I got 2 Teensy 4.1 but unfortunately over here the Ethernetkit is not yet available.
I cut a Ethernet cable in half an connected the RJ45 with a coupler. (The little switch is for the crossover.)
Is this an acceptable solution or am I missing anything? I'm wondering because the Ethernet Socket in the kit is a inductive coupled device and the socket on my old Arduino Ethernet Shield is connected directly.
The LED is via a 1K Resistor to Gnd; there is no Capacitor.
Is this a good alternative compared with the Ethernetkit? No. One should only use it if there is nothing else available because everytime the cable is plugged in or out the soldered wires are moved and will pretty soon break off.

View attachment 21014

I am not sure on this. I would guess not, you would probably have wanted to do this in the MII/RMII. Maybe the PHY supports this you can look inside the datasheet:
https://www.ti.com/lit/ds/symlink/dp83825i.pdf

However as I understand it most are L1 notions for signal drivers. Most built to drive cable via the magnetics. In theory you could make a PHY work like this but it would not likely be covered by IEEE.

 

[geraldt]

Hi I would like to use a more rugged style RJ45 which will be panel mounted. The normally supplied Magjack can't easily be mounted on a panel as far as I can tell, so I found this device.. It's a Neutrik NE8FDV with punchdown connections on the back, bt i can't work out how to wire it to the teensy and if it will need additional components. I hope someone might be able to offer some help. Or is there anything else that might be better suited and will mount on a metal panel easily?

PS it does seem to have some capacitance implemented on the board but I can't see any resistors or discrete components. It has no led either, but that doesn't bother me as I plan to use a separate led anyway...





Thanks

 

[defragster]

Based on only the included image - that looks like just a way to panel mount a connector to take signals to a punch down block - or like a wall socket fixture - an alternative to in wall wiring - just a breakout connector to transition from 'external cable' to a bare wire connection where the wires are properly punched down.

That could work in the noted case if so where mounting that externally would then go inside the panel and then hand wired back to correct standard 568A or 568B to a custom cable ending in an RJ45 end to plug into the proper Teensy Magjack board to Teensy 4.1 PCB pins.

It does not seem like that is an active Magjack component so the wires from that cannot go straight to the adapter PCB, but would return to proper pins on a cable end to plug into the board like PJRC sells providing the active Magjack.

 

[GyroGearloose]

Your joce is a DMX style connector. Do you want to use the round metal sleeve with the lock, or just plug in a regular RJ45 cable?
You might also want to consider a RJ45 Keystone Module Jack. Those jacks can be mounted in Outlets, or Panels or boxes.
https://www.ebay.de/sch/i.html?_from=R40&_trksid=p2047675.m570.l1313&_nkw=Keystone+Jack&_sacat=0
This guy has made two videos how to make cables.
https://www.youtube.com/watch?v=k6-_D5-0LEI
Please note, that there is a difference between Cat5 and Cat7
What I would do is to leave either the Magjack and add a patch cable, or only use the 2mm pitch ribbon cable and solder it to the new cable, or insert it directly in the part you found.
Avoid soldering the cable directly on the Teensy.

Hi I would like to use a more rugged style RJ45 which will be panel mounted. The normally supplied Magjack can't easily be mounted on a panel as far as I can tell, so I found this device.. It's a Neutrik NE8FDV with punchdown connections on the back, bt i can't work out how to wire it to the teensy and if it will need additional components. I hope someone might be able to offer some help. Or is there anything else that might be better suited and will mount on a metal panel easily?

PS it does seem to have some capacitance implemented on the board but I can't see any resistors or discrete components. It has no led either, but that doesn't bother me as I plan to use a separate led anyway...

View attachment 23190

View attachment 23191

Thanks

 

[defragster]

... or only use the 2mm pitch ribbon cable and solder it to the new cable, or insert it directly in the part you found.
...

As noted in p#23 - if I'm reading the 'picture' right and the notes about no active components: I don't see that as an option - to use the ribbon without a magjack - or cabling punchdown wires direct to Teensy?