I want to use LCD and mcp3208 simultaneously.

spi0(gpio8,9,10,11) is port for LCD and spi1(gpio16,19,20,21) is port for mcp3208.

spi0 channel is always on and spi1 is opened when I want to collect data.


1) when I checked spidev, there are spidev0.0, 0.1 but spidev1.0,1.1. Should I make spidev1.0 and 1,1? If then, How can I make them??

2) Someone said using PIGPIO. so, I installed pigpio is raspberry pi3. My example code is like below.

import pigpio
import RPi.GPIO as GPIO

pi = pigpio.pi()

if not pi.connected:

# pi.spi_open(0, 1000000, 0)   # CE0, 1Mbps, main SPI
# pi.spi_open(0, 1000000, PI_SPI_FLAGS_AUX_SPI(1)) # CE0, 1Mbps, auxiliary SPI

lcd=pi.spi_open(0, 1000000, 0) # CE0, main SPI
pi.spi_read(lcd, 2)

subprocess.call('setterm -cursor off', shell=True)
subprocess.call('spincl -ib', shell=True)
# pins connected from the SPI port on the ADC to the RPi
SPICLK  = 11
SPICS   = 8

# set up the SPI interface pins


# pin connected to read
sensor_adc0 = 0;
sensor_adc1 = 1;
sensor_adc2 = 2;
sensor_adc3 = 3;
sensor_adc4 = 4;
sensor_adc5 = 5;
sensor_adc6 = 6;
sensor_adc7 = 7;
subprocess.call('clear', shell=True)

def readadc(adcnum, clockpin, mosipin, misopin, cspin):
        mcp = pi.spi_open(0, 1000000, PI_SPI_FLAGS_AUX_SPI(1))
        pi.spi_read(mcp, 1)
        if ((adcnum > 7) or (adcnum < 0)):
                return -1
        GPIO.output(cspin   , True)

        GPIO.output(clockpin, False)  # start clock low
        GPIO.output(cspin   , False)  # bring CS low

        commandout = adcnum
        commandout |= 0x18            # start bit + single-ended bit
        commandout <<= 3              # we only need to send 5 bits here
        for i in range(5):
            if (commandout & 0x80):
                GPIO.output(mosipin, True )
                GPIO.output(mosipin, False)
            commandout <<= 1
            GPIO.output(clockpin, True )
            GPIO.output(clockpin, False)

        adcout = 0

        # read in one empty bit, one null bit and 12 ADC bits
        for i in range(14):
                GPIO.output(clockpin, True )
                GPIO.output(clockpin, False)
                adcout <<= 1
                if (GPIO.input(misopin)):
                        adcout |= 0x1

        GPIO.output(cspin, True)

        adcout >>= 1 # first bit is 'null' so drop it
        return adcout

if __name__ == '__main__':
        sensor0 = readadc(sensor_adc0, SPICLK, SPIMOSI, SPIMISO, SPICS)
        print sensor0

It didn't work.

How can I fix it??

Thank you for your help.

  • The Pi only has kernel drivers for SPI0 with support for 2 channels. In fact you can use more with your own CE code, and/or hardware. There is no driver for SPI1 and it impractical to write one. There is plenty of code which uses SPI1, and supports additional channels. I don't see why the 2 SPI0 channels wouldn't work for your 2 devices, but there is non-kernel code to use SPI1 (I have never had the need). – Milliways Feb 3 '17 at 7:30
  • I don't understand what you are trying to do. SPI is a bus system. Only one SPI device can be using the bus at any one instant (the one which has asserted slave select). What is the output of ls /dev/spi*? – joan Feb 3 '17 at 9:44
  • How can I fix it??, the best way to fix it is to rewrite your code because it is such a mess. But before you rewrite it, take time to understand how SPI works and read the API document such as pigpio, for how to use spi_open in particular. SPI0 supports two channels by controlling CE0 and CE1 while sharing the rest of the signals (MOSI/MISO/CLK) in a time-division manner, but it can't be used at the same time. – hcheung Jun 2 '18 at 0:38

just add this to /boot/config.txt and reboot


it should enable auxiliary SPI with SPI1 CE2 (GPIO16) for channel select

see also /boot/overlays/README



| improve this answer | |

Thank you all for the tips.

In my case, just add this to /boot/config.txt and reboot


I changed too in the MFRC522 library the following parameter: /dev/spidev0.0 to /dev/spidev1.0

In the pins were like this:

  • SDA/CE2: 36
  • MISO: 35
  • MOSI: 38
  • SCKL: 40
  • RESET: 13
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