Re: ESP32 PPP disconnection re-connection issue
Posted: Mon Nov 08, 2021 4:45 am
by Sprite
That resistor is there because of EMC reasons... if during your EMC testing you find out that there's emissions from your UART1 TX pin, you could try also putting a 470 ohm resistor there, but from what I know, it's only an issue on UART0. Regardless, having or not having the resistor shouldn't affect anything else.
Re: ESP32 PPP disconnection re-connection issue
Posted: Mon Nov 08, 2021 3:49 pm
by AdiXPS
That resistor is there because of EMC reasons... if during your EMC testing you find out that there's emissions from your UART1 TX pin, you could try also putting a 470 ohm resistor there, but from what I know, it's only an issue on UART0. Regardless, having or not having the resistor shouldn't affect anything else.
Thanks so much for information. I've scoped the RX/TX and I notice that there are voltage spikes while RX/TX in UART1. when I add series resistor its much more smoother.. I've came over this issue
https://github.com/espressif/arduino-esp32/issues/2198.
Moreover, may I know the value of internal pullup resistor in esp?
Would like to get your opinion on above, thanks!