5PCS MAX3232 3.3V to 5V DB9 Male RS232 Serial Prot to TTL Converter Module Root Connector for Arduino Raspberry Pi and Microcontrollers

I have a computer with an RS232 I/O. I needed to monitor my Arduino's activity, but not using USB because if the computer disconnects the USB, the arduino resets.

I've only tried one of the two (I only need one), but it worked as expected. As with all serial COM stuff, it took a minute for all of the USB-to-Serial and Arduino settings to be correct, but I was able to send data from my laptop to the Arduino through this. It worked exactly as expected and as needed.

These work fine in circuit, but unlike the units pictured, the ones I received did not have mounting holes, which complicates my project. They did, however, helpfully come with some small jumper wires.

Worked to connect a RS-232 device to raspberry pi GPIO ports.

Anmbest 2PCS MAX3232. I used these boards with the Raspberry Pi Compute Module 4. At first they worked, but then I started having problems with them. After a power cycle, they would refuse to transfer data in one direction until I sent data in the other direction. It took me a while to figure out that they were the problem because I was developing a serial port driver. I tried both of these boards that I purchased and they both have the same problem. I'm using 3.3V logic levels. The other problem is that the included cables had badly crimped connectors that either refused to slide over pins, or were so loose that they wouldn't stay connected.I found a different board with a different chip on it that so far works reliably. The other boards include RTS and CTS which I don't really need, but they don't seem to cause a problem being unconnected. The other boards also don't come with a four-pin connector or a cable. I had to solder on pins myself and buy a cable.

I was able to fix my rs232 communication issues with this. Needs a power supply of 3.3-5v to work.

One of the circuits is defective.

Not sure on the manufacturer of this chip but based on other manufacturers, I noticed the following about this board.1. The capacitors selected on this board are appropriate for a 3.3V input signal but not a 5V input signal.2. There is no bypass capacitor installed.3. The unused inputs are not grounded.3. The TX part of the chip seems to work.4. THE RS232 RX part of the board DOES NOT WORK. On both units I received, the RX pin messed up the RS-232 signal. I verified a good signal with my oscilloscope and once connected to the board, the signal no longer had enough amplitude to produce a TTL output.

値段も安く問題なく動作しましたが、他の方からも指摘されているように、オス型の商品説明の写真だと基板に丸穴が開いていますが、実際に届いた商品には開いていませんでした。あとこれは余談ですが、最初いにしえのアナログモデム用のストレートケーブルで接続してしまい、しばらくそれに気づかずドツボにはまりましたが、クロスケーブルにつなぎ替えたら問題なく使えました。