whofferbert
New member
Hello!
I've been using the Teensy 4.0 and the audio shield successfully for a while now, and I started looking at adding an ILI9341 display to the project.
On this page, it details alternate pins that can be used on the Teensy 3.2 if the audio shield is in use as well.
Looking over the pinout for Teensy 4.0, and I was able to find alternate pin locations for MOSI (26/35), MISO (34), and SCK (27), but I ran into trouble with the CS and DC pins.
Once the audio shield is attached to the Teensy 4.0, it seems there is only one CS pin left: 36.
Is there a good work around for this? I understand it's possible to emulate SPI in software, but that it "is much, much slower and prevents your sketch from doing useful work meanwhile."
I'm curious if attempting to use another pin for CS or DC connection, and some software for this task may have a poor effect on the real-time audio processing.
(Later edit) Looking a bit further at the Adafruit_ILI9341 library source, it seems that it's okay to pass -1 to the CS, if CS is tied to Ground.
According to the datasheet for the ILI9341, CS low is to enable the chip select.
Since the rest of the MOSI/MISO/SCK is happening on different pins than what the audio shield uses, would that be a reasonable way to use the display along side the audio shield on the Teensy 4.0?
Any suggestions or guidance would be greatly appreciated! Thank you for your time.
I've been using the Teensy 4.0 and the audio shield successfully for a while now, and I started looking at adding an ILI9341 display to the project.
On this page, it details alternate pins that can be used on the Teensy 3.2 if the audio shield is in use as well.
Looking over the pinout for Teensy 4.0, and I was able to find alternate pin locations for MOSI (26/35), MISO (34), and SCK (27), but I ran into trouble with the CS and DC pins.
Once the audio shield is attached to the Teensy 4.0, it seems there is only one CS pin left: 36.
Is there a good work around for this? I understand it's possible to emulate SPI in software, but that it "is much, much slower and prevents your sketch from doing useful work meanwhile."
I'm curious if attempting to use another pin for CS or DC connection, and some software for this task may have a poor effect on the real-time audio processing.
(Later edit) Looking a bit further at the Adafruit_ILI9341 library source, it seems that it's okay to pass -1 to the CS, if CS is tied to Ground.
According to the datasheet for the ILI9341, CS low is to enable the chip select.
Since the rest of the MOSI/MISO/SCK is happening on different pins than what the audio shield uses, would that be a reasonable way to use the display along side the audio shield on the Teensy 4.0?
Any suggestions or guidance would be greatly appreciated! Thank you for your time.
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