Does it work with older audio boards?
Yes its actually easier than you think. I came across a HDMI shield that can be used with a T3.6 and I adapted it so you can use it with the T4. This is the shield post: https://forum.pjrc.com/threads/54711-Teensy-4-0-First-Beta-Test?p=207850&viewfull=1#post207850
And this is some results: https://forum.pjrc.com/threads/54711-Teensy-4-0-First-Beta-Test?p=208337&viewfull=1#post208337 The testing was done with 10" GoChic display.
Kind of put any further mods on hold because of higher priority testing.
Is that 1.5" x 2.6" overall?
Would it make sense to add a GND pad spaced with the 'ON' Pin pad to place a button there?
I'd recommend placing the USB host connector closer. The SD signals run at 50 MHz, which is pretty fast and definitely wants GND routed as close together with with CLK as possible. But USB host runs at 480 Mbit/sec, and there's already almost 2 inches of not well impedance controlled routing from the BGA to the end of that flex cable.
Remember to use 2 capacitors for whatever USB current limit chip you choose. Try to resist the typical thinking that bigger must be better. I'd recommend 100 to 150 uF for the output cap, and 2.2 to 4.7 uF for the input cap. If space is an issue, that smaller cap wants to be as close as possible to the current limit chip, and the big output cap wants to be close to the USB connector.
Also a good idea to place a decoupling capacitor close to the SD socket. Those tiny micro SD cards don't have space for much on-board capacitance. Especially if you run the power and ground wires across the board to reach the socket, you really want come capacitance close to the socket.
Sorry for asking a seemingly stupid question, but what's the purpose of the carrier rails?
What do you think of the SD card connector on a separate tiny pcb? The flex pcb could already be soldered to it
Drastic change - but would ideally make sure the USB Host wasn't compromised - or those signals didn't compromise anything else in transit across the PCB - as long as the SD and USB host don't bother each other.
...here is his/her revision D break out board...
What do you think of the SD card connector on a separate tiny pcb? The flex pcb could already be soldered to it
I'd connect for testing.If I were to make a few pre-release breakout boards, are there some folks who'd be interested in putting the USB host port through some rigorous testing? Shipped out free, of course. Let me know and we can work out the details from there.
@loglow - check RED box around USB Host connect on post #35 - "That underside placement shown here in RED BOX on top layer." - just copied on top to show spacing and ease of hacking in MSPaint. That doesn't make it a workable solution - but the cable passage was noted.There's one big issue with this proposed layout, and it's the same problem that already exists with the 3.5/3.6 Standard breakout: the Teensy doesn't sit high enough above the breakout PCB for its onboard Micro USB port to be accessible when a full-size USB port is in that spot. If (and only if) the Teensy is socketed with low-profile headers, then there's enough clearance. I want to avoid that situation for this board because, like you said below, the USB host port is a very useful addition.
I use he/him pronouns and my real name is Dan, but I don't care if people call me Tall Dog (business name) or loglow (username). Thanks for explaining purpose of the carrier rails! They're a very cheap addition that's very useful to some, and they're easy to remove if not needed.
I'm hesitant to do this. Mostly because I still want to break out those 6 GPIO pins for general purpose use, so at that point why not just have pads for the Micro SD as well? At some point I might resurrect my Micro SD extension board/cable with an added panel-mount option though.
I'd connect for testing.
Count me in for any alpha/beta testing!
It would be interesting to try your method out... I am building some of my own boards, which are a pain with those ribbon cables...If I were to make a few pre-release breakout boards, are there some folks who'd be interested in putting the USB host port through some rigorous testing? Shipped out free, of course. Let me know and we can work out the details from there.
There's one big issue with this proposed layout, and it's the same problem that already exists with the 3.5/3.6 Standard breakout: the Teensy doesn't sit high enough above the breakout PCB for its onboard Micro USB port to be accessible when a full-size USB port is in that spot. If (and only if) the Teensy is socketed with low-profile headers, then there's enough clearance. I want to avoid that situation for this board because, like you said below, the USB host port is a very useful addition.
I use he/him pronouns and my real name is Dan, but I don't care if people call me Tall Dog (business name) or loglow (username). Thanks for explaining purpose of the carrier rails! They're a very cheap addition that's very useful to some, and they're easy to remove if not needed.
I'm hesitant to do this. Mostly because I still want to break out those 6 GPIO pins for general purpose use, so at that point why not just have pads for the Micro SD as well? At some point I might resurrect my Micro SD extension board/cable with an added panel-mount option though.
I have a t4 and would love to try an help too. I have a bunch of different usb devices I could try, including a usb sound card, a usb bluetooth thingy, 2 wireless mice, and a couple thumb drives and a HD to usb adaptor and a m2 to usb adaptorJust sent you guys private messages to follow up about this.
Thanks, however there is nothing in my PM inbox yet (5:15pm) - don't know how long it usually takes...![]()
I have a t4 and would love to try an help too. I have a bunch of different usb devices I could try, including a usb sound card, a usb bluetooth thingy, 2 wireless mice, and a couple thumb drives and a HD to usb adaptor and a m2 to usb adaptor
As for putting it through it's paces, I do still have lots of USB work left to try out. Things like getting my branch to support multiple BT devices to be in good enough shape to get pulled in...
Don't know what happened there, but I resent it.
PM sent.
No prob. Let me know if things settle down and you'd like to hop in!
Well, if you want another guinea pig to test your board let me know. I pretty much attached everything under sun to the T4 so far.
I got the PM and replied … @loglow - KurtE as well was suggesting his USB Host work would be well suited to inclusion.
Latest revision. This is likely to be the first limited pre-production run of boards and cables:
...
Thanks to all the volunteer beta testers! I'm very interested to see how smoothly assembly goes, and how well the USB host port functions in this arrangement.