EXT Cartridge Module

Not all interrupts can wake up the chip

Good point! On the T4.0, all pins can wake it up.

There are still two free SPDTs on U9… cough cough

The only sensible thing I can come up with is switching between device and host mode via these.
So in Mode-A, it’s a host via the USB hub, and in Mode-B it’s a device via the Teensy.

I have no clue to mux the Teensy between cartridge or host using only what’s left.

Generally got a bad feeling about switching between those tough, I wouldn’t do that physically with a SPDT, bound to confuse the bus somehow. On the other hand, it should be no problem at all.
Also it’s def. harder to route and I want to order boards sooner than later.
I’d say it’s an edge case that doesn’t warrant a general feature. If you need a device, put it as a chip in your cart or bang it out for v1.0. Excuses excuses :slightly_smiling_face:

Lastly, I just noticed that there’s some space for a coin cell holder where the cam connector was. Having an RTC that keeps time would be nice to have in my experience.

I’d say with that, all the features for v1.0 are decided, looking at the first post it has come a long way, anyway.


Update: Routing so far is complete, DRC checks out and all that’s left is the silkscreen.

As the CAM_EN and CAM_LED pins are no longer a thing, I used those for CART_MODE and TEENSY_WAKEUP. I think this is worth a shot, will order this next week.

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Fantastic! Really looking forward to it.

Oh btw, on second thought, I think now that we have a MCU, there’s no need for DeviceTree mods.

We can create a platform device that reports device connect/disconnect to the kernel.

Conceptually, it’s not different from USB, PC-Card etc., except that Teensy is the PHY.

I got two simple boards completed today: the RPi interface and a simple passthrough to a header.
Luckily, the only functionality missing from the RPi card is SPI2, but you got ADCs and CAN.
Win some lose some :smiley:
As the EEPROM I selected the M24M02
Here’s the pinout:

Meanwhile, I started the mechanical design while the parts arrive.
It is keyed, so no worries that you plug it in backwards.
Lazy Susan of the design so far

Based on the C64 design, I’ll 3D print those tomorrow and do a test fit.

Curious, I see you have the DT model imported into FreeCad. Did you convert it to features or just mesh?

I tried to convert it to solid and it ate a few hours and gigabytes and gave up(

Did you convert it to features or just mesh?

I just imported the mesh, and then reduced it even some because I’m computing on a potato by today’s standards.

Good news: the cart design fits nicely, parts are ordered and PCBs are in production.
In a months time I might have the first prototype assembled.

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Oooh nice. You gonna solder the parts by yourself?
The skills required for soldering smt stuff are beyond my pay grade ($0).

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Oooh nice. You gonna solder the parts by yourself?

Of course!

Here’s a sneak peek of the RPI and passthrough cart PCBs.


Edit: It appears that I sent it too soon, that stray trace on pad 10 wasn’t intended.
Nothing a little bodging can’t fix tough.