fastest way to communicate between two teensies

[kteepa]

I have a teensy 3.2 and a teensy 4.1 plugged into the same laptop. Both teensies are connected to the same ground (the laptop via USB), and there is a jumper cable from the teensy 3.2 DAC/A14 pin to an analog pin on the Teensy 4.1. The teensy 3.2 reads an analog sensor value, clips and compresses that to a [0,1023] range and sends it to the teensy 4.1 via the analog pin to analog pin connection. Unfortunately the signal is quite noisy, and I don't like having to trim and compress the sensor readings to a small range.

I will be adding 4 more teensy 3.2s, each reading one of their own sensors and sending to an analog port on the teensy 4.1.

The reason I didn't do I2C or serial or SIP were because I am under the impression that analog read/write is the fastest, and it seemed the most straightforward. I would like to read and report sensor values at 4kHz.

What is the best way to do this?

 

[PaulStoffregen]

Both teensies are connected to the same ground (the laptop via USB), and there is a jumper cable from the teensy 3.2 DAC/A14 pin to an analog pin on the Teensy 4.1.
....
Unfortunately the signal is quite noisy

Connect a ground wire directly between the 2 boards. Keep it close to the analog signal wire. Twisting it together with that wire is a good way to make sure they stay close to each other.

 

[kteepa]

Connect a ground wire directly between the 2 boards. Keep it close to the analog signal wire. Twisting it together with that wire is a good way to make sure they stay close to each other.

Ok. If I do this with 5 teensy 3.2 boards inputting to the analog port on the teensy 4.1, will the circuit pass the overall current rating of the teensy 4.1? or no because all the teensy 3.2s are in parallel?