Frank Eory asked 3 years ago
Hello,
I plugged an ESP32-CAM to an esp32-cam-mb as shown here: https://randomnerdtutorials.com/upload-code-esp32-cam-mb-usb/
In the Arduino environment, I can upload the code of CameraWebServer from page 44. On the arduino serial monitor, I get text . I press reset, I get serial text. In Putty serial terminal, I don’t get text. How do I fix this?? I am guessing the reset hooked up on the serial is getting different stimulus.
Sara Santos Staff answered 3 years ago
Hi.
Are you sure you’re connecting with the right settings using Putty?
Make sure you close the Arduino IDE Serial Monitor before attempting a connection using Putty.
Regards,
Sara
Frank Eory answered 3 years ago
Hello Sara,
I was hoping mostly you may have come across the schematic.
>Are you sure you’re connecting with the right settings using Putty?
I verified the baud rate a few times.
>Make sure you close the Arduino IDE Serial Monitor before attempting a connection using Putty.
Putty doesn’t allow you to open a serial COM port that is not available or is used by another program. I did shut down the Arduino IDE completely.
I found some info here, but no schematic:
https://www.reddit.com/r/esp32/comments/mscliq/anyone_have_the_schematic_for_the_esp32cammb/
The root cause is most likely the RTS and DTR. In Putty, I don’t have much control over RTS and DTR. All I could do is enable flow control type to use RTS, XON/XOFF, or put no flow control. What I would need is a direct control of the RTS and DTR through a menu. On Reddit, there was a person with similar results as me. He could not get the serial communication to work with Putty either, but had it work in the Arduino IDE.
I was having some problems starting the firmware. I learned the ESP32-CAM was doing brownout resets. It said so sometimes in the serial text. Sometimes, it just sent one character continously. I plugged in a USB voltage and current meter and saw the USB was dipping below 4.4V.
Best regards,
Frank
Sara Santos Staff answered 3 years ago
Hi.
After reading that link on reddit, it seems that Arduino IDE can toggle the right pins automatically to be able to program the board. But,putty doesn’t do that.
Unfortunately, I don’t know how to solve that issue. Have you tried with an FTDI programmer? However, I’m not sure if that would solve the issue.
The brownout error is many times related to insufficient power supply.
Regards,
Sara
Steve Mercer answered 3 years ago
You don’t need RTS (Request To Send) and DTR (Data Terminal Ready) these days. No flow control will work. These were used in the good old days when computers were real slow and serial speeds could overwhelm them. Computers today are so fast that they don’t need those archaic mechanisms any longer. So long as you have TX and RX connected to the correct pins you should be good to go.