5pcs USB to Serial USB to TTL CH340 Module with STC Microcontroller Download Adapter

These are by far my favorite USB/TTL devices. For one - there's a jumper that allows selection between +3.3 or +5V. The other cool feature is that they are using the CH340 chip. I've found this to be significantly more reliable on Windows as compared to the other commonly used chip - the SiLabs CP201x. The problem with the CP201x chips is with Windows - so many times after Windows updates are applied, the drivers are replaced with a default that causes them to no longer function until the proper drivers are manually re-installed from the manufacturer's web site. That's not the case with these using the CH340. They always seem to just work. (not an issue for linux, of course) I also like the fact that these devices have clear heat shrink tubing, protecting these devices (and your computer!) from stray wires or other things that inevitably fall on them during development and prototyping. As an extra bonus, M-F jumper wires are included; great for connecting to breadboard (but note that you'll need F-F jumpers if connecting directly to something like a Raspberry Pi) Note the default jumper setting connects the Tx/Rx pins as shipped; this allows for immediate operational verification using something like putty to confirm operation using serial loopback.

Worked great to unbrick a Belkin RT3200 / Linksys E8450 affected by OKD (OpenWRT kiss of death) The included cables have female and male ends and so did not directly connect into the JST PH connector (also male). I inserted the male ends from two cables together and then used the combined cable to connect the CH340 to the router. The ends connected to the JST PH connector were a loose fit.

I used one of these to adapt my cellphone with the rxtxlite android app to my uSDX+ V2 qrp transceiver. Everything went together easily, and worked perfectly. Now I can change bands, modes, and adjust frequency with the phone instead of the buttons on the radio. Cheap and easy to do! I would recommend.

I tried these because they were cheaper than the typically cited FTDI converters. Online, users post about having issues connecting to ESP32-CAMs. I worried using these would complicate things. Initially, these failed to upload properly at the default 921600 baud (using the Arduino IDE). However, they worked when fine when I cut back to 115200 baud. It might have worked at a in-between rate, like 460800, but i didn't try. I can't blame these convertors, because people were having the same issue with the FTDI type converters too. Clarification on use: These have a jumper to choose between 5V and 3.3V logic levels. This doesn't affect the voltage of the 5V or 3.3V output pins, just the TX/RX logic levels. The ESP32 needs 3.3V logic levels, but people say it programs more reliably if you use its 5V Vcc pin. I set the jumper for 3.3V, but connected the 5V output pin to the 5V Vcc of the ESP32, letting it regulate its own supply. This worked very reliably, for me.

Worked absolutely amazing on my aurdino! Couldn’t have been more please. USB port, connectivity where great.

Great item. Worked good. Good quality!

Purchased: HiLetgo 5pcs USB to Serial USB to TTL CH340 Module with STC Microcontroller Download Adapter Good price for a set of 5. Tested device with VOM and saw 5.0VDC and 3.3VDC fine. Programmed a SonOff S20 with Espurna. I had no luck with the 3.3VDC pin - no LED lamp lite Error with PyTool programming: /home/pete/Downloads# esptool.py --port /dev/ttyUSB0 write_flash --flash_size 1MB --flash_mode dout 0x00000 espurna-1.14.0-itead-s20.bin esptool.py v2.3.1 Connecting.... Detecting chip type... ESP8266 Chip is ESP8266EX Features: WiFi Uploading stub... Running stub... Stub running... Configuring flash size... Compressed 484528 bytes to 346038... Wrote 484528 bytes (346038 compressed) at 0x00000000 in 30.5 seconds (effective 126.9 kbit/s)... Hash of data verified. Leaving... Hard resetting via RTS pin... Configuring flash size... Compressed 484528 bytes to 346038... Wrote 484528 bytes (346038 compressed) at 0x00000000 in 30.6 seconds (effective 126.8 kbit/s)... File md5: c28049d971cd068d6f0dacbc28cbc531 Flash md5: 8b3f90623777a1a700dffa326ba79476 MD5 of 0xFF is e2b933bac685c79e6215cb3456c1f855 A fatal error occurred: MD5 of file does not match data in flash! Then tested with the 5VDC pin and it worked. Very odd. Running stub... Stub running... Configuring flash size... Compressed 484528 bytes to 346038... Wrote 484528 bytes (346038 compressed) at 0x00000000 in 30.5 seconds (effective 126.9 kbit/s)... Hash of data verified. Leaving... Hard resetting via RTS pin... Returning all 5 devices and purchasing one new device.

Came quickly, worked. Couldn't be happier.