STM32 RS485 Shield Fix

I have an STM32-based shield whose RS-485 channel works fine on a single drop, yet the moment several devices share the same daisy-chained cable the bus starts losing or corrupting bytes. The issue is clearly hardware-side, so I want the existing schematic reviewed, all mistakes uncovered, and an upgraded design delivered that will let the network run error-free no matter how many nodes I add.

The job revolves around classic RS-485 best-practice: proper biasing and termination, fail-safe receiver design, common-mode handling, transceiver choice, surge/ESD protection, ground reference strategy and solid layout. Feel free to lean on Altium, KiCad or any other CAD you prefer so long as the final files drop back into Altium without translation headaches.

Deliverables
• Corrected schematic file plus PDF snapshot
• Short change log explaining every edit and why it cures the corruption
• Recommended termination/bias resistor values, cable length limits and node count guidance
• (Optional but welcome) layout tweaks or a placement/trace-routing guideline for the differential pair
• need to correct encoder wirings
• need to correct motor outputs to digital isolator

Once I can scope-probe the revised board and see clean signalling with no missing data on a multi-node chain, the work is done.