Board reboots after connecting two spi lines.

[GiovanniRaseraF]

          On the circuit I made, the mcp and gps module communicate over the same spi line, but the cs pins are separate. After pulling data over MCP, when I do digitalWrite("mcp' cs pin", HIGH), it goes into SPI_FLASH_BOOT mode and boots continuously.

At the same time, when I run the code without making any connections, the DATA part is empty and the ID part is written. Is it normal? I'll be glad, if you help me

Originally posted by @MehmetAliAksoy1 in https://github.com/dedalqq/esp32-mcp2515/issues/4#issuecomment-1454732263

[GiovanniRaseraF]

hi @MehmetAliAksoy1 please post the code you think is important here, so we can try to help you :)

[MehmetAliAksoy1]

i only added two lines to your example code. The reason I added was to make mcp's cs pin HIGH and cut off communication, gps' cs pin to LOW and open it to communication. When i add this like that, on serial monitor SPI_FLASH_BOOT_MODE writing repeatedly

[MehmetAliAksoy1]

Actually i want to select cs pin and take data from gps and spi

[MehmetAliAksoy1]

how can i add gps's spi pin to same spi channel? please help @GiovanniRaseraF

[GiovanniRaseraF]

Check some things:

• you are setting up MISO MOSI CS CLK correctly, this means you are using the write pins. for example for the esp32 800L I'm using this pins:

  #define MISO  19
  #define MOSI  23
  #define SCK   18
  #define SS    5

• check the PINOUT of your board if you don't know the pins to chose,
• check if you are compiling for the write target, not all esp32 versions are the same,
• if you have I2C communication on the gps try that to see if it works independently.

[MehmetAliAksoy1]

Pins are correct, but i want to select CS pin when i use

[GiovanniRaseraF]

Okay, please try all the things and report your findings. And please provide the name of the gps that you are using.

[MehmetAliAksoy1]

include

define GPS_CS 26

void spi_read(char* data) { digitalWrite(GPS_CS, LOW); delay(10); for (int i = 0; i < 100; i++) { data[i] = SPI.transfer(0x00); } digitalWrite(GPS_CS, HIGH); }

void setup() { Serial.begin(9600); SPI.begin(14, 12, 13, 26); //sck, miso, mosi, ss pinMode(GPS_CS, OUTPUT); digitalWrite(GPS_CS, HIGH); }

void loop() { char gps_data[100]; spi_read(gps_data); Serial.println(gps_data); delay(1000); }

This gps code working and print datas. Gps module is Neo-m8.

When I combine this code with the CAN code, I cannot receive data from GPS. Even when I turn the MCP's CS pin high, data starts coming directly from the can.

[MehmetAliAksoy1]

When i call SPI.begin() after The canbus integration at Setup, it is working, why? @GiovanniRaseraF

[GiovanniRaseraF]

I think the problem is that you are using SPI in the wrong way, i cannot test it so i cannot be sure. And i think that Neo-m8 uses I2C at 9600 baud.

The best thing i can tell you is to:

• Create a sketch with only canbus working
• Create a sketch with GPS Neo-m8 using I2C communication ( for reference use this tutorial GPS tutorial)
• Create a third sketch with the combined code

And at the end post the code in you git and link it here or post it here with a markdown tag; it will be easier to read

[MehmetAliAksoy1]

No, we made connection with both of them on HSPI. But gps's select pin 26. I can not use i2c

[MehmetAliAksoy1]

And also your code does not work for me now

[MehmetAliAksoy1]

I solved the problem but i did not any connection to mcp2515 from read the data. But on the serial monitor: ID: 447 DATA: ID: 42C DATA: ID: 50A DATA: ID: 12E DATA: ID: 341. What is this data came from? How is it possible? @GiovanniRaseraF

[MehmetAliAksoy1]

There is no change when SS pin select another free pin.

[Cyberko102]

I solved the problem but i did not any connection to mcp2515 from read the data. But on the serial monitor: ID: 447 DATA: ID: 42C DATA: ID: 50A DATA: ID: 12E DATA: ID: 341. What is this data came from? How is it possible? @GiovanniRaseraF

Could you show me your code for can bus?