I am running into an issue using HardwareSerial(1) while I also have an SD card mounted.
I am using the builtin HardwareSerial library to map uart1 to pins 32 & 33, and the following works fine:
Code: Select all
HardwareSerial surveillance_serial(1);
HardwareSerial scanner_serial(2);
...
surveillance_serial.begin( 9600, SERIAL_7N1, 32, 33, false, 50);
scanner_serial.begin( 9600, SERIAL_7E1, 16, 17, false, 50);
...
surveillance_serial.read() called in a FreeRTOS task at intervals
scanner_serial.read() also called in a FreeRTOS task at intervals
Now I've added an SD card into the mix, using the builtin SD library:
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#include "FS.h"
#include "SD.h"
#include "SPI.h"
...
if (!SD.begin(5)) {
Serial.println("ERROR: SD card mount failed");
return;
}
Serial.println("SD card mounted.");
However (!!) mounting the SD card causes surveillance_serial on UART1 to stop receiving data. I have removed all other SD card functions from my code and determined that the line above, SD.begin(5), definitively triggers the problem . If I comment out SD.begin(5) with no other changes, UART1 works great again.
TL;DR: Using the SD card over SPI works. Using hardwareserial UART1 on GPIO 32/33 works. When I try to do both, uart1 stops receiving data.
Debugging so far:
I know that under the hood, my call to .begin() on hardwareserial(1) is remapping the GPIO functions internally to GPIO 32/33.
I see that the "default" pins for u1RXD and u1TXD are GPIO9 and GPIO10, which also share the pin with "spiHD" and "spiWP". However, my SD card is wired (and working) on the standard SPI pins (vspi?) GPIO's 5, 18, 19, 23.
I see there are separate <SD.h> libraries for arduino and esp32. I am compiling and uploading from the Arduino IDE. Is it possible it's pulling in the wrong library?
Any ideas would be appreciated - thanks!