bdoan

Since the time I posted this question, I tried a resistive divider Vtest->100k->ADC->100k->Gnd The readings are still accurate

I am needing to read voltages that may exceed the 3.3V max limit of the 4.1 inputs. I can certainly divide down the input voltage but I am also needing to limit the loading of the measured source to 10s of microamps. What is the impressed input...

Running W10 Removing while (!Serial) {}; fixed it

It works, Thank you

I am having an issue with serial communication on a Teensy 4.1 (1) -- When I first power the board up, I cannot receive serial characters from the Teensy with my Delphi application. (2) -- If I close that application and open Terminal.exe , The...

Paul, After trying multiple software interfaces and 2 different Teensy 4.1 setups, I decided to abandon my scheme of sending USB audio to the Teensy Line Out and simultaneously reading back audio from Line In. While looking at examples for...

Thanks again for your help

I hope this is not too out of line but I need your help on another thread. The is is mission critical for me releasing a test fixture to production. https://forum.pjrc.com/index.php?threads/teensy-4-1-audio-adapter-crosstalk.76230/

I am using a software interface that sends and receives audio to the (USB) device. When I send an audio file or even just a tone, I see response coming back from the teensy audio input side. This should not happen

I re-tested this bare 4.1 / adapter with 200 ohm terminations on the Lin and Rin Still see audio out showing up on audio in

This is being used on a test fixture where one input may gave a low impedance (<100 ohms) and the other is switched by a mux.

Ok. So I will add a buffer amp. Thanks.

This happens with just the audio adapter piggy backed on the 4.1 with header pins. No external circuitry. If I short the Lin and Rin, the crosstalk goes away. The Codec has 29k line input impedance. Is this just leakage on the adapter pcb?

I seem to be getting crosstalk between Line In and Line Out on the Audio Adapter. How should the ground terminals in the Line In / Line Out section be wired with respect to other grounds on the 4.1 and the overall system? If I ground the Line In...

So if I close serial monitor, will it complete quickly?

Why does Arduino repeatedly need to download the " package_teensy_index_json " If this index is only about 20K , why does it take 5 minutes to update in Arduino?

Can I call the Teensy Loader from another application (other than Arduino)? I am building my user interface in Delphi and can send Windows Shell commands.

Thanks

If I don’t include this code, will the volume and gain be at 100%

I am using a 4.1 as the controller in a test fixture. I want to protect the GPIO pins against worst case faults (short to ground or short to 5V) If I simply build out the output pins with 1.5K to limit the current, is that sufficient?

I am using the 4.1 with audio shield as a USB to analog audio interface. Running Windows 10 and seeing that the Windows sound control panel volume slider does not affect the headphone output level. Is this by design or am I doing something...

The problem never was with addressing the serial ports. It was with handling character strings.

It is working on Arduino

Maybe I didn’t make my question very clear. But I’ve got it working using my original method. Thanks

I am trying to use code that has worked for me for 20 years on other platforms but does not on Arduino. I need to be able to compile a text buffer and decode on the basis of individual characters in specific positions. Please Advise // Globals...

if (USBrxData[0] == '>') // DSP serial { Serial.print(">"); SendToDSP() } This is not detected > character at the first position in the string. Also I cannot print out the string that I have assembled from incoming characters. My...

Does this change the way I handle characters and strings? The ports work properly but my problem is with compiling character buffers from individual characters and testing specific positions in the buffers for matching characters. Also...

I am wanting to compile text buffers for each UART port. With all other IDE and compilers that I have used in the past, this method worked fine. But apparently Arduino handles strings differently. I want to be able to create a string from...

I found code

Thanks. Shift and test bit? Or just AND with a mask to get the bit value?

I am not clear on how Arduino code works with the "shiftout" function. I need to shift out 12 bits. should I use the shiftout or just bitbang with other functions? void WriteToDAC(void) { //#define DAC_CLK 28 //#define DAC_Data 29...

I agree, the problem is not with the Teensy. I have tried my new layout using the AT43301 and an old (working) device using the same hub device. I will rebuild my circuit using the TUSB2046.

Mark, If the Teensy works properly with other hubs, how does initialization timing (start serial) affect enumeration of the USB?

Yes, I see that. My confusion was that all other processors that I have used sense the Vbus to begin enumeration

Thanks

So are you saying that the Vbus pin from the host USB connector is not sensed when the Teensy is powered from the 5V pin?

The product page for the Teensy 4.1 states: When USB power is not used, 5V power may be applied to the VIN pin. Because VIN & VUSB are connected, power should not be applied to VIN while a USB cable is used, to prevent the possibility of power...

I have not attempted firmware solutions. My hunch is that the AT43301 has some limitations that the TUSB2046 and other hubs do not. At 12 Mbit, will the Teensy have enough bandwidth to handle UART and USB audio (simultaneously)? Also, I do not...

Thank you for all your advice. I am specifically looking for conditions that would cause the AT43301 hub to fail. A TUSB2046 hub works, a Belkin powered hub works and direct connections to the PC work. Therefore, I am ruling out code or...

Please read the entire thread. It connects properly when connected directly to the PC. The problem is with the home built Hub

Thanks. Would the fact that 5V is exactly 5.0V and Vusb is 5.1V be an issue?

And where (in code) do I set this speed?

If what you did works for you, great. I don’t believe it addresses my issue. I may have a USB speed compatibility issue with the hub

Is the Teensy trying to enumerate at Full Speed or High Speed? I'm running UART and USB Audio. Also, if I separated 5v (Teensy supply voltage) from Vusb, is the Teensy still monitoring Vusb to start enumeration??

Yes, 5v and Vusb are separated (cut) on the bottom of the board as instructed

If I use a (commercial) powered hub or direct connection to the computer, the USB, 5v power sequence does not matter.

The Teensy is powered by a separate regulated 5v supply, not the Vusb. I have separated the pad jumper under the 4.1 board. I can see that the Teensy only enumerates when I connect it to the computer directly and also supply 5v I will try...

I am having a problem connecting the 4.1 through a "non-powered" USB hub. I cut the connection between 5V and Vusb on the bottom of the 4.1 board. If I power the 5V with a separate supply and connect the USB micro connector directly to the...