Sharing an SPI pin to i2c

Projects Programming
1

Hi,
I use esp8266 to connect to 4 relay, 1 SPI(Lora module), 1 interrupt pin, 1 i2c. I lack 1 pin for I2C.
Here's what my sketch does:

The SPI is a LORA module(4 SPI pin, 1 busy pin) which keep listening for incoming command. The I2C will read data from sensors every 5 minutes or when it get command from the LORA.

Anyway to share the SPI pins with the i2c without interrupting its listening operation and without causing the i2c trouble while the SPI is working?

Thanks;

2

Why 6 pins? Standard SPI pins include MOSI MISO SCK and CS - 4 pins only

3

Sorry, 5PINs MOSI,MISO,SCK, BUSY and NSS. Not 6 pins

4

If you have only one SPI device connected, you can use the same pin for both CS and SS

5

Yes, only 1 SPI device.

6

What's that? Do you use it? If not then leave it disconnected.

7

I try your suggestion. But the SPI response is invalid. I try CS(NSS)+SCK on GPIO14(esp8266 default SPI pin) and also on GPIO15. both failed

8

Sorry, it's required by the LORA module I use. It's for knowing if a command is still being executed and can run next command or not.

9

I did not say that you should combine SCK with any other pin. You can use the same pin for SS(NSS) and CS.

10

Or you could switch to using an ESP32 that has more GPIO available to you.

11

Yes, I use the same pin for both NSS and CS. But the response from the Lora module is invalid.

12

Is it valid if you use different pins for NSS and CS? If no - that you need look for error in the other place

13

Yes, the LORA response a valid command when use different pins.