looking at this a year later, the TTL voltage levels on the AdaFruit USB adapter are 3.3V compliant, not 5V TTL compliant.. you need a level shifter to get them compatible 😉👍 at 34:35 you can clearly see the logic “1” level is 3V
That wasn’t the problem. It was a software issue: the port was being set to use hardware flow control. It only worked with USB serial adapters that provided a simulated RTS/CTS. DJ changed his code to turn off flow control and that fixed the issue.
@@ChrisMasto good to see it’s solved, I’m picking up a NABU later today from the original barn seller, one of the few pluses in living in MA, he’s asking $140 for them now, sais he’s down to the last few hundred. I have the same RS-422 to USB adapter comming from Amazon that was recomended… I guess you can do the direct TTL interface, but building that 40 pin adapter looks to be more work, plus the RS-422, as you’ve demo’d has a lot more length if twisted pair cabling is used.. I know you wanted to prove it could be done 👍 BTW, already tried a NABU on the MAME emulator, was impressed except it kind of locked up my mouse 🙄
@@ChrisMasto BTW, I have that same AdaFruit USB-TTL cable, and looked it up, it is CMOS/3.3V logic compatible as I stated , from the AdaFruit page on the adapter: "Technical Details There are four wires: red power, black ground, white RX into USB port, and green TX out of the USB port. The power pin provides the 5V @ 500mA direct from the USB port and the RX/TX pins are 3.3V level for interfacing with the most common 3.3V logic level chipsets."
@@mwolrich The CP2102 is 5V tolerant on the inputs, and it should be pretty clear from the video that the output level is sufficient for the NABU's UART. In any case, the idea behind this video was to try to figure out why it wasn't working. Once I tried it with different software, it became clear that it was a software problem. Further exploration (e.g. th-cam.com/video/PYC9fdRiZhA/w-d-xo.html) pinpointed the specific issue. You're technically correct, and it's always possible that due to individual variations in tolerances, what worked on my machine might not work on someone else's. I wasn't trying to suggest using this combination of hardware, it was just a live streamed troubleshooting session.
Thanks again! Enjoyed the stream!
Huzzah! Nice to see my NABU Network software worked for you.
looking at this a year later, the TTL voltage levels on the AdaFruit USB adapter are 3.3V compliant, not 5V TTL compliant.. you need a level shifter to get them compatible 😉👍 at 34:35 you can clearly see the logic “1” level is 3V
That wasn’t the problem. It was a software issue: the port was being set to use hardware flow control. It only worked with USB serial adapters that provided a simulated RTS/CTS. DJ changed his code to turn off flow control and that fixed the issue.
@@ChrisMasto good to see it’s solved, I’m picking up a NABU later today from the original barn seller, one of the few pluses in living in MA, he’s asking $140 for them now, sais he’s down to the last few hundred. I have the same RS-422 to USB adapter comming from Amazon that was recomended… I guess you can do the direct TTL interface, but building that 40 pin adapter looks to be more work, plus the RS-422, as you’ve demo’d has a lot more length if twisted pair cabling is used.. I know you wanted to prove it could be done 👍 BTW, already tried a NABU on the MAME emulator, was impressed except it kind of locked up my mouse 🙄
@@ChrisMasto BTW, I have that same AdaFruit USB-TTL cable, and looked it up, it is CMOS/3.3V logic compatible as I stated , from the AdaFruit page on the adapter: "Technical Details
There are four wires: red power, black ground, white RX into USB port, and green TX out of the USB port.
The power pin provides the 5V @ 500mA direct from the USB port and the RX/TX pins are 3.3V level for interfacing with the most common 3.3V logic level chipsets."
@@mwolrich The CP2102 is 5V tolerant on the inputs, and it should be pretty clear from the video that the output level is sufficient for the NABU's UART.
In any case, the idea behind this video was to try to figure out why it wasn't working. Once I tried it with different software, it became clear that it was a software problem. Further exploration (e.g. th-cam.com/video/PYC9fdRiZhA/w-d-xo.html) pinpointed the specific issue.
You're technically correct, and it's always possible that due to individual variations in tolerances, what worked on my machine might not work on someone else's. I wasn't trying to suggest using this combination of hardware, it was just a live streamed troubleshooting session.