Pin questions
Posted: Thu Jul 12, 2018 7:24 pm
I am trying to understand pin functions and mapping of ESP32 and need some help. have the following questions:
1. GPIO 37 and 38 or sensor_capp and sensor_capn. These pins are not on the WROVER module's breakout pads. They are probably under the metal cap and have the 270pF caps on them as indicated in the WROVER schematics. Am I correct?
2. GPIO 36 and 39 or sensor_vp and sensor_vn. Since they are coupled to 37 and 38 by these caps, should I still use them for general purpose inputs?
3. Can someone help me understand how IO_MUX and GPIO_Matrix work together to map certain features to pins? I understand that analog inputs and some SD card interfaces and UART0 are attached to pre-determined GPIO pins by IO_MUX. There is no way to, say, map ADC1_CH0 to any pin other than GPIO 36 etc. but there are many choices of GPIO pins when mapping, say, UART1 TX RX pins. How?
1. GPIO 37 and 38 or sensor_capp and sensor_capn. These pins are not on the WROVER module's breakout pads. They are probably under the metal cap and have the 270pF caps on them as indicated in the WROVER schematics. Am I correct?
2. GPIO 36 and 39 or sensor_vp and sensor_vn. Since they are coupled to 37 and 38 by these caps, should I still use them for general purpose inputs?
3. Can someone help me understand how IO_MUX and GPIO_Matrix work together to map certain features to pins? I understand that analog inputs and some SD card interfaces and UART0 are attached to pre-determined GPIO pins by IO_MUX. There is no way to, say, map ADC1_CH0 to any pin other than GPIO 36 etc. but there are many choices of GPIO pins when mapping, say, UART1 TX RX pins. How?