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1 vote

Is this a legitimate RS485 wave shape?

Yes, technically that is correct, and you have most likely determined the way it operates correctly. So, to recap, the transmitter is enabled on logic 0 (active state), and change to logic 1 (idle ...
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2 votes

How does this RS485 transceiver work?

The board is very questionable, or at least it may be made for some specific non-standard purpose, as there are many things that are not typical for a standard RS-485 interface. It is possible that ...
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3 votes
Accepted

How does this RS485 transceiver work?

The normal (idle) state of the Pico UART output is high; this turns the transistor on through R1 or R11, which disables the transmitter (DE low) and enables the receiver (/RE low). Received data ...
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2 votes

How does this RS485 transceiver work?

An RS-485 bus has three states: high, low, and idle. An UART signal has two states: high and low; when the UART is idle, the signal just stays high. It is therefore not possible to reliably control an ...
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0 votes

How does this RS485 transceiver work?

For 4-wire (full duplex) RS485 between two devices, all you need is really TX and RX. The driver is permanently enabled. For 2-wire (half duplex), you need three GPIO pins: driver enable, RX, and TX. ...
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RS-485 Network Topology with Backbone and Daisy-Chain Stubs

The bus backbone is max 20cm and it has ten 1.5 meter stubs connected to it. That is basically a star topology, which is not how RS-485 is meant to be used. It is against best practices already, ...
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1 vote

RS-485 Network Topology with Backbone and Daisy-Chain Stubs

If you look at the Maxim datasheet you referenced, you will see that they show the application as a single string of connections with impedance matching resistors at each end. This is to control ...
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