Guru
Joined: 05/10/2019
Location: United KingdomPosts: 8955
| Posted: 11:45am 08 Jul 2025 |
All very true! I'm not pretending that this board is industrial gear, more a way of adding extra IO to a Pico mounted somewhere nearby. For industrial stuff I'd only use RS485 or, in severe cases, opto. That's become a lot cheaper than it used to be, especially if the distance isn't too great for plastic fibre.
For this particular board you might get improved performance using multi-drop COM, purely because the COM ports are buffered. It's still only local though as the pullups are only resistive, not active. You also can't use it if the RTC is fitted as that assumes a I2C bus. I could have given the communication lines their own GPIO pins and put the local I2C stuff on another pair, but that's using pins that might be required for something else.
Oh, a bit of rearrangement and the YD-RP2040 will fit now (preferably shorting pins 39 and 40). GP23 and GP29 come out to pads near the RTC battery.
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Edited 2025-07-08 21:49 by Mixtel90