Thanks for your reply, when i test this code in UIFlow 1.7.7 on Fire: from machine import I2S import os, uos from wav import wave #initialize the I2S device i2s = I2S( mode = I2S.MODE_MASTER | I2S.MODE_TX | I2S.MODE_DAC_BUILT_IN, rate = 16000, bits = 16, channel_format = I2S.CHANNEL_ONLY_RIGHT, data_format = I2S.FORMAT_I2S_MSB) #uncomment the following line if you have issues mounting the sd #uos.sdconfig(uos.SDMODE_SPI,clk=18,mosi=23,miso=19,cs=4) #create a function to play the wav def wav_player(fname): wav = i2s.set_dac_mode(I2S.DAC_RIGHT_EN) i2s.sample_rate(wav.getframerate()) i2s.bits(wav.getsampwidth() * 8) i2s.nchannels(wav.getnchannels()) i2s.volume(20) while True: data = wav.readframes(1024) if len(data) > 0: i2s.write(data) else: wav.close() break # Playing WAV audio file lcd.clear() lcd.print('working',0,0,0xffffff) try: uos.mountsd() except: os.mountsd() lcd.print('sd card not mounted',0,50,0xffffff) pass while True: wav_player('/sd/test.wav') i2s.stop() wait(5) I have another error on line 39: module object has no attribute 'mountSD'