Unable to use more than one multiplexer at a time

Troubleshooting and Support
1

Hi! I’ve been following this tutorial: Cd4051 Multiplexer Tutorial Is Here!

I’ve got a single multiplexer working great, but adding a second one hasn’t worked so far. I can use either one or the other, but trying to use both crashes the Seed. Here’s my code, adapted from that tutorial:

#include "daisy_seed.h"
using namespace daisy;
DaisySeed hw;

int main(void)
{

    hw.Init();

    AdcChannelConfig adc_cfg;
    adc_cfg.InitMux(seed::A0, 8, seed::D0, seed::D1, seed::D2); 
    adc_cfg.InitMux(seed::A1, 8, seed::D3, seed::D4, seed::D5); 

    hw.adc.Init(&adc_cfg, 2); // crashes
    hw.adc.Start();
    hw.StartLog();

    while(1)
    {
        System::Delay(250); 
        
        hw.Print("Input 1: %d", hw.adc.GetMux(0, 0)); 
        hw.Print("  ");

        hw.Print("Input 2: %d", hw.adc.GetMux(0, 1)); 
        hw.Print("  ");

        hw.Print("Input 3: %d", hw.adc.GetMux(0, 2));  
        hw.Print("  ");

        hw.Print("Input 4: %d", hw.adc.GetMux(0, 3)); 
        hw.Print("  ");

        hw.Print("Input 5: %d", hw.adc.GetMux(0, 4));  
        hw.Print("  ");

        hw.Print("Input 6: %d", hw.adc.GetMux(0, 5)); 
        hw.Print("  ");

        hw.Print("Input 7: %d", hw.adc.GetMux(0, 6));  
        hw.Print("  ");

        hw.PrintLine("Input 8: %d", hw.adc.GetMux(0, 7));   
    }
}

This line consistently crashes the Seed and I can’t figure out why:

hw.adc.Init(&adc_cfg, 2);

Would love some tips! Thanks!

2

Hi,you can try something like the following (untestet):

...
AdcChannelConfig adc_cfg[2];
adc_cfg[0].InitMux(seed::A0, 8, seed::D0, seed::D1, seed::D2); 
adc_cfg[1].InitMux(seed::A1, 8, seed::D0, seed::D1, seed::D2); 

hw.adc.Init(&adc_cfg, 2);
...

By the way, you can use the same pins for the mux a,b,c.

1 Like
4

Yes!! That worked! Thank you!

1 Like