Description
Board
ESP32-S3
Device Description
Custom ESP32-S3 keyboard but it should work on any ESP32-S3 devkit with USB connection.
Hardware Configuration
N.A.
Version
v3.1.0
IDE Name
Arduino IDE
Operating System
macOS
Flash frequency
80MHz
PSRAM enabled
no
Upload speed
921600
Description
I’m currently porting my project to the latest version of the Arduino Core but I'm experiencing data loss when using the USBCDC implementation with large chunks of data. It seems that the data is not reliably received and a buffer overflow occurs.
This seems to be related and exactly what I am experiencing: https://www.esp32.com/viewtopic.php?t=38858
Downgrading to 2.0.17 makes the code work again.
I suspect the issue might be related to how data is queued or buffered internally within the USBCDC implementation. If there are known limitations or configurations that could mitigate this issue, I’d really appreciate any guidance or suggestion.
I've provided an example that computes the SHA1 of the sent data to confirm integrity.
Sketch
#include <Arduino.h>
#include <ArduinoBearSSL.h>
#include <USB.h>
#include <USBCDC.h>
USBCDC m_serial;
ESPUSB* m_usb;
String m_buffer;
int m_last_message_ms;
void ingest_cdc_data(void)
{
m_serial.println("GOT DATA");
while (m_serial.available()) {
m_buffer += m_serial.readString();
}
if (m_buffer.length() == 0) {
return;
}
m_last_message_ms = millis();
}
void calculate_buffer_sha1()
{
if(m_buffer == "")
return;
// calculate the sha1 of the buffer if it's been more than 1 second since the last message
if (millis() - m_last_message_ms > 1000)
{
SHA1.beginHash();
SHA1.print(m_buffer);
SHA1.endHash();
print_hash();
m_buffer = "";
}
}
void print_hash()
{
while (SHA1.available()) {
byte b = SHA1.read();
if (b < 16) {
m_serial.print("0");
}
m_serial.print(b, HEX);
}
m_serial.println();
}
void
usb_event_callback(void* arg,
esp_event_base_t event_base,
int32_t event_id,
void* event_data)
{
if (event_base == ARDUINO_USB_CDC_EVENTS) {
switch (event_id) {
case ARDUINO_USB_CDC_RX_EVENT:
ingest_cdc_data();
break;
case ARDUINO_USB_CDC_RX_OVERFLOW_EVENT:
m_serial.printf("USB cdc overflow\n");
break;
default:
break;
}
}
}
void
setup()
{
// put your setup code here, to run once:
m_buffer = "";
m_last_message_ms = 0;
USB.onEvent(usb_event_callback);
m_serial.onEvent(usb_event_callback);
m_serial.begin(115200);
m_usb = &USB; // get the USB object
m_usb->begin();
}
void
loop()
{
// put your main code here, to run repeatedly:
calculate_buffer_sha1();
delay(1);
}Debug Message
--- CORRECT OUTPUT WITH ARDUINO ESP32 VER 2.0.17 ---
GOT DATA
GOT DATA
GOT DATA
GOT DATA
GOT DATA
GOT DATA
GOT DATA
GOT DATA
GOT DATA
GOT DATA
GOT DATA
GOT DATA
GOT DATA
GOT DATA
128DA61AA85A72155E5229129D83E6044181FB0A
--- OUTPUT WITH ARDUINO ESP32 VER 3.1.0 ---
GOT DATA
GOT DATA
GOT DATA
(then it stops and doesn't accept any more data)
Other Steps to Reproduce
Open an Arduino Serial monitor and paste the following text into the Message box (No Line Ending, 115200 baud).
111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111
Expect the SHA1 being: 128DA61AA85A72155E5229129D83E6044181FB0A
I have checked existing issues, online documentation and the Troubleshooting Guide
- I confirm I have checked existing issues, online documentation and Troubleshooting guide.