hi I try to connect to an arduino nano 2 DAC (sparkfun 4725) 1 current sensor (ina219) 1 LCD 20X4 display 1 1307 RTC (tiny rtc) and ADS1115 to read 1 analog input with i2c and a sd card module with spi (with and without 74hc125) and to display the results on the serial monitor too.
it read and wirte the correct data to the DACs and from the ina219 but it not make the strings for the lcd and serial monitor correct and the lcd shows some wired symbols
the power supply is fillterd.
any Ideas what could go wrong? and how to fix it?