user70399: I'm trying to connect an Arduino Uno with a BGT PM2510 sensor (which uses 7-12 V DC) by using a UART TTL to RS485 Two-way Converter.
The only thing I wonder about is: can the sensor damage the MCU?
According to the information on the 12 V sensor, it says:
Output signal: RS485 (Modbus protocol). I did measurements on the A & B ports of that sensor; the multimeter showed 3.3 V.
My question is, can the sensor damage the MCU? I intend to connect the Arduino and sensor as in the diagram below:


user61722: You should be fine.
RS-485 does specify signal levels of ±1.5 V to ±5 V, but even so, and even when the sensor would misbehave or when the common mode voltage is low or high, there is still the TTL-to-RS485 converter in the middle that has 5 V TTL logic on the Arduino side.
As long as the TTL-to-RS485 converter is properly connected to the Arduino and working as it should, the Arduino is safe.

70399: <p>I'm trying to connect an Arduino Uno with a <a href="https://www.alibaba.com/product-detail/BGT-PM2510-Industrial-Dust-Particle-PM2_62480865889.html" rel="nofollow noreferrer">BGT PM2510 sensor</a> (which uses 7-12 V DC) by using a <a href="https://www.elecrow.com/uart-ttl-to-rs485-twoway-converter-p-1545.html" rel="nofollow noreferrer">UART TTL to RS485 Two-way Converter</a>.</p>
<p>The only thing I wonder about is: can the sensor damage the MCU?</p>
<p>According to the information on the 12 V sensor, it says:</p>
<p><code>Output signal: RS485 (Modbus protocol)</code>. I did measurements on the A &amp; B ports of that sensor; the multimeter showed 3.3 V.</p>
<p><strong>My question is, can the sensor damage the MCU? I intend to connect the Arduino and sensor as in the diagram below</strong>:</p>
<p><a href="https://i.stack.imgur.com/Zw06h.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Zw06h.png" alt="enter image description here" /></a></p>
 61722: <p>You should be fine.</p>
<p>RS-485 does specify signal levels of ±1.5 V to ±5 V, but even so, and even when the sensor would misbehave or when the common mode voltage is low or high, there is still the TTL-to-RS485 converter in the middle that has 5 V TTL logic on the Arduino side.</p>
<p>As long as the TTL-to-RS485 converter is properly connected to the Arduino and working as it should, the Arduino is safe.</p>
