Hi,
I'm new to microcontrollers and I'm quite impressed with the Teensy 4.
I'm working on an audio visualization project, where I have four INMP441 microphones connected to the Teensy's two I2S interfaces and an Adafruit ILI9340C 320x240 display on SPI (see ASCII & PNG images). I'm glad that so far everything works fine.
For diagnosis & latency measurements, I would like to add audio output to this setup. I have an Audio Shield which works well on its own but I'm reluctant to just plug it on top of this setup since the audio shield seems to need most of the pins I already use for the hardware currently connected.
So: will putting an audio shield on top of the Teensy work as long as I only use the audio shield's headphone and/or line-out ports for output?
If this is possible, is there anything I should be aware of when doing so?
Thanks for taking the time reading this!
PS: if anyone is inclined to answer, I have a few follow-up questions that
don't seem to deserve their own thread:
I'm new to microcontrollers and I'm quite impressed with the Teensy 4.
I'm working on an audio visualization project, where I have four INMP441 microphones connected to the Teensy's two I2S interfaces and an Adafruit ILI9340C 320x240 display on SPI (see ASCII & PNG images). I'm glad that so far everything works fine.
Code:
+---------------------------------- SCK--| I2S1
| +------------------------------- WS---| (2x INMP441)
| | +- SD --|
| | +-----+ |
| | | | |
+-----------------|--|--------------------|--+ | |
| V G 3 23 22 21 20 19 18 17 16 15 14 13 | | |
| i N V | | |
| n D 3 | | |
| | | |
| Teensy 4.0 MCU | | |
| | | |
| G | | |
| N | | |
| D 0 1 2 3 4 5 6 7 8 9 10 11 12 | | |
+-----------|--|--|--|--------|--|--|--|--|--+ | |
| | | | | | | | | | |
| | | | +--|--|--|--|-----|--+
| | | | | | | | |
| | | | | | | | +-- SCK---| TFT
| | | | | | | +-------- MISO--| (Adafruit
| | | | | | +----------- MOSI--| ILI9340C
| | | | | +-------------- CS----| 320x240)
| | | | +----------------- DC----|
+--|--|--|----------------------------- RST --|
| | |
| | +----------------------------- SD----| I2S2
| +-------------------------------- SCK---| (2x INMP441)
+----------------------------------- WS----|
For diagnosis & latency measurements, I would like to add audio output to this setup. I have an Audio Shield which works well on its own but I'm reluctant to just plug it on top of this setup since the audio shield seems to need most of the pins I already use for the hardware currently connected.
So: will putting an audio shield on top of the Teensy work as long as I only use the audio shield's headphone and/or line-out ports for output?
If this is possible, is there anything I should be aware of when doing so?
Thanks for taking the time reading this!
PS: if anyone is inclined to answer, I have a few follow-up questions that
don't seem to deserve their own thread:
- Do I risk to fry the teensy, audio shield or display if I plug them in incorrectly (As long as I power the teensy using USB and make sure to only use the Teensy's 3.3V output for powering any peripherals)?
- Should I connect the display's only unused input port (SD Card Chip Select) to anything?
- Is there any chance to use SD storage later on (via audio shield or display)? If yes, which SD card reader (audio shield or display) would be preferrable?
- The display's brightness drops significantly in the first second when powered via USB. Would a different power supply be preferrable? (I don't do PWM backlight control, I just power the display with the Teensy's 3.3V output pin in the hope that I don't exceed the 250 mA stated in the documentation.