Daisy chaining an spi display with another spi on arduino

Other Hardware Displays
1

Hi, I have a project that uses a real time clock to trigger a relay on and off at certain times. I'm trying to add a 128x64 i2c lcd, but the real time clock already uses the i2c pins that was supposed to be used for the lcd. Is it possible to connect more than one device to the pins?

Edit: sorry i meant i2c (scl and sda pins), not spi

Edit 2: I just googled the question again with i2c instead of spi and found an answer thanks for the help anyway :slight_smile:

2

Let's have the (weblink) specifications of each of these devices, a statement of which Arduino you have and a schematic of how you presently have them connected and how you propose to connect them.

3

It is not "daisychaining" with SPI because it is a bus and the 3 main connections are in parallel. That is MOSI, MISO and Clock are all shared between devices. Only the CS (Chip Select) is unique per device and it is brought low when the device may access the bus. Most real time clocks, incidentally, are not SPI but I2C.

4

6v6gt:
It is not "daisychaining" with SPI because it is a bus and the 3 main connections are in parallel.

Mind you it can be if all devices ripple through.

5

Paul__B:
Let's have the (weblink) specifications of each of these devices, a statement of which Arduino you have and a schematic of how you presently have them connected and how you propose to connect them.

Im using an arduino nano, connected to a ZS-042 real time clock module (Arduino DS3231 ZS042 AT24C32 IIC Module Precision RTC Real time Clock Memory | eBay) and I want to connect a 128x64 oled i2c display (https://www.amazon.com/UCTRONICS-SSD1306-Self-Luminous-Display-Raspberry/dp/B072Q2X2LL/ref=pd_lpo_vtph_328_lp_img_3/145-2655086-0643718?_encoding=UTF8&psc=1&refRID=CB68BPWN9HA5H6Y27Y3C). At the moment, I am using the Wire library to connect the rtc module to the arduino. This is how the rtc module is connected to the nano: (Imgur: The magic of the Internet). Since the rtc module is using the i2c pins that were gonna be used for the display, I can't connect the display. Unless you can connect more than one i2c device on those two pins.

6

The I2c bus.

You can, theoretically, connect up to 128 devices to those two pins. Each device must have a unique I2C address.