Analog and audio

Posted on January 12, 2018 at 12:26Hello Sir,We have used opamp ic LM358 in our audio project, which used for amplification of signal from mic to adc of microcontroller.Could you please verify the attached circuit, let me know if you have any comments.RegardsJom

Posted on July 24, 2017 at 15:03Greetings. I need to use the mp3 codec library specifically developed for STM micro-controllers for my audio project (mentioned on the ST website). Nevertheless, I neither found the library to download it nor was I able to know which STM32 family members it supports. I am currently using the stm32f405 MCU. Any help will be much appreciated!#stm32 #audio #mp3 #codec #library

Posted on January 05, 2018 at 00:52Hello,I'm sorry but I am new to the forum and have no experience with ARM platforms at all. I have just realized Arduino projects or other ones using SBC's like Raspberry, but for my upcoming project the STM32F4 mcu could possibly be the best choice.The requirements for my project are:Simultaneous audio playback of up to 4 (better: 6) stereo wav files from usb key!I just need one jack for analog audio output, so the mixing of the audio channels should be done software based.Another requirement is a best possible playback latency (response time). With other words: Every sound should be played as instantly as possible after requesting the playback for an arbitrary file. There will be hundreds of sound files (having very different lengths at a sampling rate of 44 or 48 KHz) that needs to be played disordered and instantly like the sounds on a piano or keyboard.It was nice if I could support mp3 format for at least

Posted on December 22, 2017 at 08:22STD5N52U   Does anyone know this one have 2 device heat sink? Attached is label photo and parts picture

Posted on November 28, 2017 at 12:11Hello,I have a question about the TS3022 dual comparators.The datasheet states an input bias current of 300nA max. over full temperature range.Compared to similar competitor parts this is almost two orders of magnitude higher.I was wondering if this specification is correct or should it be pA i.s.o. nA?Thank you,Paul--

Posted on December 04, 2017 at 12:03Hi All,I am using an SPDIF receiver, It has been connected to the STM32F401 I2S. The diagram is as bellow,SPDIF Receiver (I2S Master)  -> STM32F401 (I2S slave Receiver DMA) -> STM32F401 (DAC DMA) -> STM32F401 analog outputFor a while system works perfect and I can see the analog output follows the signals which SPDIF receiver gets. But after a random amount of time which is vary from 3 minutes to 40 minutes suddenly the STM32F401's I2S DMA starts receiving wrong values. static void MX_I2S2_Init(void){hi2s2.Instance = SPI2; hi2s2.Init.Mode = I2S_MODE_SLAVE_RX; hi2s2.Init.Standard = I2S_STANDARD_MSB; hi2s2.Init.DataFormat = I2S_DATAFORMAT_16B; hi2s2.Init.MCLKOutput = I2S_MCLKOUTPUT_DISABLE; hi2s2.Init.AudioFreq = I2S_AUDIOFREQ_48K; hi2s2.Init.CPOL = I2S_CPOL_LOW; hi2s2.Init.ClockSource = I2S_CLOCK_PLL; hi2s2.Init.FullDuplexMode = I2S_FULLDUPLEXMODE_DISABLE; if (HAL_I2S_Init(&hi2s2) != HAL_OK) { _Error_Handler(__FILE__, __LINE__)

Posted on November 21, 2017 at 12:55The original post was too long to process during our migration. Please click on the attachment to read the original post.

Posted on November 19, 2017 at 06:09hello!I am new to this forum.All of us, except the deaf, hear a wide variety of sounds.  The most amazing thing I think is dolphins. They can not only make the sounds we hear, they can make and hear what we can not hear.I want to know what the sound of the dolphin sounds we can not hear.

Posted on October 30, 2017 at 23:15I work (again) on USB Audio on STM boards. It works, I get the audio from PC to board (or vice versa), so far OK. FW works, example/demo code is helpful, no issues from a SW coding point of view.My issue is: How to deal with two independent audio clocks?The DAC on board gets MCLK (Word Clock) from MCU (or something else). USB audio comes in, e.g. every 1 ms there is a new audio packet, e.g. 192 bytes (48 stereo samples) when 48 KHz sample rate, 16bit stereo. But this clock is generated by the PC. The host generates this 1 ms period, independently of MCU board (and its I2S/DAC there).So, at the end, USB and DAC on board are running with different, completely independent and not synchronized clocks.It results in following: it is a bit tricky to synchronize the USB with the Audio DAC, the DMAs for it, it depends when USB kicks on, when it will get a packet with audio framesthis is completely unrelated to each other: USB frames can be ready when the DMA

Posted on September 23, 2017 at 21:13Hello ,I'm trying to connect Adafruit microphone using SAI of the STM32L4. This microphone uses I2S protocol, and delivers as output PCM 24 bits data,(The microphone includes Segma delta filter and a decimator which are used to convert PDM data to PCM data), over sampling rate fixed at 64 and Clock frequencies from 2.048Mhz to 4.096MHz are supported.Until this step, I can receive audio data from the SAI, but I didn't know how to validate if they are well received or not. As solution, I'm trying to read the audio buffer using an other SAI + the WM8960 audio codec available in the STM32L4 board. But, I'm not hearing the real sounds that I have recorded. In that case, I want to ask if it's right to use the WM8960 codec to read this kind of audio data?The data size and the sampling rate used by the microphone can impact on the codec choice.Thanks for the help #sai-audio-record

Posted on July 20, 2017 at 14:13Hello Community,Does the SAI sub-block clock source matter when it is in Synchronous Slave mode with the other sub-block? In other words, should the two sub-blocks have the same clock source?Thank you.

Posted on September 21, 2017 at 00:41Greetings I'm currently looking for a spice model of the L7805CV 5V Regulator for my design simulation , I've looked on the product page and keep seem to find anything . Is there anyone who can point me in the right direction?#voltage-regulator

Posted on September 06, 2017 at 19:49Hi    I am trying to build an announcement system using TDA7491P audio CLASS D amplifier. I am not able to figure out how to control the volume of the speakers using the amplifier.

Posted on April 27, 2017 at 21:22I am trying to read back I2C registers on the TDA7419 audio processor to verify their contents.  I've try both standard I2C register reads as well as the custom method on Page 29 of the datasheet (rev7).  In all cases, a NACK is received and no data is transmitted.Does register read-back work on the TDA7419.  If so, does anyone have an explicit timing diagram?Thanks!#audio-processing #i2c #tda7419

Posted on February 22, 2017 at 20:34Hi at all,I wanted to order a sample product to try to build up a own bluetooth box. After I send my request, it shows your order has succesfully created but I can't see it in the order history. After I close the tab, it shows the items in the chart again.

Posted on August 28, 2017 at 06:46For a new design, I need an AES/ EBU receiver IC that can accept balanced inputs. The STA120D seems fit. However I cannot find the product page on the ST website even though the IC is available on Mouser and Digikey.May I know the status of this product and is it recommended of new designs? Is there any other alternative that I can look into?Thanks!!Ravindra Desai.

Posted on August 22, 2017 at 16:39I would like to use TN3050H-12GY-TR SCR at 400Hz. I am just not sure how would it be rated based on SCR controlling a pure restive load using 200Vac at 400Hz.#tn3050h-12gy-tr #400hz #scr

Posted on July 27, 2017 at 13:14Hello,Datasheet recommends connecting both MUTE and STBY pins on TDA7293 using R-C for delay to avoid pop noise.I would like to know if I can connect MUTE pin using R-C, as recommended, and connect STBY pin directly to VCC.Thanks!!

Posted on July 21, 2017 at 15:26Hi,I'm using STA309A, and wondering the differnces between DDX damped ternary and binary PWM output, since there is no waveform examples in the DS. Anyone knows this? thanks a lot~Li dongsheng.

Posted on July 18, 2017 at 17:11#Help.!!! The TDA7491LP mute pin is the input port. I connected the 3.3V pullup resistor 33K resistor to the power supply, and the mute pin keeps the state of LOW state .... What is the cause? So there is no sound. .   Keep mute ...?

Posted on June 24, 2017 at 15:24The STA326 datasheet (DocID11531 Rev 9) is unclear on a couple of points, so:* Does the STA326 output power level depend on the output stage supply voltage (VCC[12][AB] on pins 4,8,11,15),or does it depend only on the digital signal chain (digital input signal and volume and effects settings) ?The output clipping level will of course depend on the supply voltage, so obviously I'm talking about power levels below clipping :)* What are the frequency limits of the XTI/CLK pin (pin 27) ?* Is there a required or recommended sequence for changing the input signal format and/or frequency ?In the CLK/XTI pin (pin 27) section on page 12 of the Datasheet, it says:'Care must be taken to provide the device with the nominal system clock frequency;over-clocking the device may result in anomalous operation, such as inability to communicate.'.So, when switching between formats, e.g. 16-bit 44.1 kHz, 48, 96 or 192 kHz (24-bit),in which order must these values and signal

Posted on June 13, 2017 at 16:45On the steval-mki138 MEMS microphones dev kit, using the STAudioHub firmware and tools, I am observing a significant time drift between 2 developments kits acquiring the same audio signal at the same time. I am now looking for ways of improving this situation. Is the STAudioHub firmware source code available somewhere? Did anybody try difference hardware or software clock configuration? Any hint would help.

Posted on June 09, 2017 at 05:47We are seeing some of our opamps failing, outputting the VCC rail regardless of input!The input signal is a BLDC fan current sense resistor and cell a is a non-inverting gain of 3x.Our sleep circuit was implemented incorrectly, during sleep Vcc is actually 1.5V instead of 0V, can this damage this part (note: other pins should be at 0V until 3.3V is applied when woken)?

Posted on June 02, 2017 at 08:40Hello ,Could you kindly recommend me any STM  kit that can be applicable for MEMS microphone ?This kit should be USB interfaced with PC, my plan is to connect it to VL812 USB 3.0 Hub Controller .Is it possible to make PDM interface with STM kit?

Posted on May 24, 2017 at 10:06We use osxAcousticEC library on STM32F401CBY6.For only one MCU, we can use OSX LicenseWizard to get license and this function is ok.But we are going to mass production, could you tell me how to batch obtain license? Thanks.