A switch to change the serial’s output level to CMOS/TTL/RS232 could fit, but would it be neccesary? Switching the output level would be nice but requires a level shifter, I don’t think the real estate on the board would accommodate this.
Still deliberating on either using an FTDI for RS-232 or using the DevTerm’s UART.
The case for the FTDI is that it’s truly plug and play through USB, for the DevTerm UART it’s less parts required but with additional configuration neccesary.
For the Ethernet chip I’m eyeing the LAN7850, tough soldering this one is going to be a challenge.
If anyone got a more accessible chip in mind, please do tell.
Sorry to break the bad news, but the cartridge system can only give out power,
not receive it and route it to the battery. Tough I got to admit, a power input module accepting low voltage AC or DC would be cool as hell.
Good news, I just assembled the revision 4 EXT module yesterday.
I’m still missing the GL850G USB hub tough, and the PWM fan controller and USB to UART I didn’t populate. Aside from that, it works very nicely!
The only cartridge I can test right now is only the breakout adapter,
but that works as expected, added a BME280 to the I2C bus and it reads out as expected.
Parts for the thermal printer and camera module will arrive next week, then I’ll give an update on that when I got to testing.
Tough the mechanical aspect for the printer is sorted out now, just needed to adjust the model slightly.
Lastly, the LAN/RS232 combo module, routing is 87% done and I expect it to be finished in two to three months, giving myself a little leeway here because this one is packed.
The RS232/dual Ethernet cart came in, and it works nicely.
Did a few tests pinging and connecting RX to TX, no problems with either.
However the activity LEDs for the RS232 port don’t seem to work, but that’s not that important.
With the camera module I have a few troubles, I can’t seem to get the OV5647 working.
It does get initialized by the kernel, but got no usable video devices yet.
If there are any experts who know the RK3399’s MIPI CSI well I could use some help in that regard.
I am working with the meshes supplied by Clockwork Pi directly, but did some decimation to make it easier to render.
I tried converting them to solids but the meshes are too detailed for that.
Pcie breakout to stick something like the rpi2040?
I tried searching for an PCIe bridge chip, no dice so far.
You can however put a RPI pico via USB without any problems.
Some way to stick an ssd and possibly boot from it?
Searched for a chip that bridges USB to mSATA, and there is one actually, the Renesas D720231A.
Tough the availability of this one is not great, LCSC has it on pre-order only.
I mean theoretically possible, but I’d rather work on the software right now before spreading even thinner with more cartridge designs.
And this one I can’t get out of my head: a cassette tape record and playback? For making backups if course
Sadly there’s not enough room to fit a mechanism, a cartridge is pretty much the size of a cassette already. Having the mechanism outside of course can work, but that would be rather top heavy and look a bit silly. Then there’s the issue that cassette mechanisms nowadays suck, so it’s not worth it in my opinion.
