Is it possible to send serial data over the GPIO port? I thought I had read somewhere that two of the GPIO pins could be set to serial Tx/Rx, but I can't find that anymore so I think I might be crazy.
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8 comments
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Brandon Official comment GPIO alternate function serial is always TTL, as it's really intended for debugging and not production.
On XT4 (Series 4 XT), XD4 (Series 4 XD) and HD4 (Series 4 HD) players with 3.5mm serial, it is RS-232 compatible.
On Revision H and newer XD3 (Series 3 XD) and XT3 (Series 3 XT) players with 3.5mm serial, it is RS-232 compatible
On Revision G and older XD3 (Series 3 XD) and XT3 (Series 3 XT) players with 3.5mm serial, it is TTLOn HD3 (Series 3 HD) players with 3.5mm serial, it is TTL
The LS423 (Series 3 LS aka LS3) and LS424 (Series 4 LS aka LS4) players have TTL serial capability on the USB C port along with standard USB functionality (on a Type A jack). This lets you have serial and USB without needing to add a USB hub that would eat more power. This is handy for folks that have touchscreens with serial on/off/input control.
You can purchase the adapter cable from our web store - http://store.brightsign.biz/
PN: CBL-USBC to USBA and 3.5mm Serial
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Bright Scripters This is interesting!
Somehow, the hardware guides do not mention the alternate function.
Worth exploring.
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Nick Young Quite handy, but worth noting it's not RS-232 so don't expect it to work if you try and use it with a display RS-232 port. I found that out the hard way (bought the standard IO model in error)!
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Bright Scripters Is it TTL level instead of RS232?
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Nick Young I think so.
https://docs.brightsign.biz/display/DOC/XTx43+Hardware+Interfaces#XTx43HardwareInterfaces-GPIO
The docs say the GPIO is 3.3v, so I reckon no RS-232 without a separate driver.
On a side note, it's interesting that the hardware serial ports never complied with RS-232 signalling levels prior to revision H
I guess that's why it's always referred to as "Serial".
Also - https://docs.brightsign.biz/display/DOC/LS424+Hardware+Interfaces#LS424HardwareInterfaces-USB
Interestingly, the LS424 hides a serial port in the USB-C connector. Not entirely sure if there's a cable on the market that would be able to make use of it. May as well just use a USB-Serial adapter via a USB-C on-the-go cable. I wonder what it was designed for.
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Nick Young Thanks for clarification Brandon. I stand corrected about the USB-C cable. Makes sense now!
One question, the docs indicate this feature is TX only. Is that correct?
Also, the hardware interfaces page for the LS3 contradicts your above clarification as it doesn't show the extra serial pins.
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Brandon Hi Nick,
The documentation is a bit fuzzy there.
On the LS4, either that's a typo or it's a quirk of USB-C funky reversible nature. A port with two TX lines and no RX lines would be quite the odd beast, even for us.
As for the LS3 it definitely works as we've both sold and used the cable prior to the LS4 model's existence.
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