Correct application of filters for multiple IDs

[brightproject]

Hello @collin80 🙂
Please help me.
I have two devices.
One is a transmitter, based on stm32f411 + mcp2515
The code is something like this:

#include <mcp_can.h>

unsigned char canMsg1[8] = {0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17};
unsigned char canMsg2[8] = {0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27};
unsigned char canMsg3[8] = {0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37};

MCP_CAN CAN(PA4);

void setup() {
  CAN.begin(MCP_ANY, CAN_500KBPS, MCP_8MHZ)
  CAN.setMode(MCP_NORMAL);
}

void loop() {
CAN.sendMsgBuf(0x10, 0, 8, canMsg1); 
CAN.sendMsgBuf(0x30, 0, 8, canMsg2); 
CAN.sendMsgBuf(0x50, 0, 8, canMsg3); 
}

The second receiving device, based on ESP32 + SN65HVD230D
The code is something like this:

#include <esp32_can.h>

void printFrame(CAN_FRAME &frame);

void setup() {
Serial.begin(115200);
CAN0.setCANPins(GPIO_NUM_21, GPIO_NUM_18);
if(CAN0.begin(500000))
{
Serial.println("Builtin CAN Init OK");
} else {
Serial.println("BuiltIn CAN Init Failed");
}

// CAN0.setRXFilter(0, 0x30, 0x7FF, false);
CAN0.watchFor(0x30, 0x7FF); //allow everything else through
CAN0.watchFor(); //allow everything else through
}

void loop() {
        CAN_FRAME message;

        if (CAN0.read(message)) {
            printFrame(message);
        }
}

void printFrame(CAN_FRAME &frame)
{
	Serial.print("ID: ");
	Serial.println(frame.id,HEX);
	Serial.print("Ext: ");
	if(frame.extended) {
		Serial.println("Y");
	} else {
		Serial.println("N");
	}
	Serial.print("Len: ");
	Serial.println(frame.length, DEC);
	for(int i = 0;i < frame.length; i++) {
		Serial.print(frame.data.uint8[i], HEX);
		Serial.print(" ");
	}
	Serial.println();
}

I can't filter messages, all messages coming to the CAN bus come to the receiving device and the filters don't work, or I configure them incorrectly.
The code was taken from the examples

esp32_can/examples/CANTestESP32_Both/CANTestESP32_Both.ino

Line 63 in 66d1440

CAN0.setRXFilter(0, 0x100, 0x700, false);

and

esp32_can/examples/CANTestESP32_BuiltIn/CANTestESP32_BuiltIn.ino

Line 41 in 66d1440

CAN0.watchFor(0x100, 0xF00); //setup a special filter

Using another library mcp_can.h, I can filter messages by shifting the mask and ID 16 bits to the left.

CAN.init_Mask(0, false, 0x7FF << 16);
CAN.init_Filt(0, false, 0x30 << 16);

[collin80]

This line you've got in there lets all traffic through:

CAN0.watchFor(); //allow everything else through

Don't have that line if you want to filter. Instead just keep the line that lets 0x30 through and that's all that should get through.

[brightproject]

Thank you for your response.
I found some explanation in the code, although this is a slightly different project, but I think there are some common points with esp32_can.

https://github.com/collin80/due_can/blob/master/howtouse.txt