Working on the final Space Rocks (i)

The components for the second two Space Rocks needed to take up less space. In the case of Undarum, the amplifier was too large. Shown here is the circuit on a new PCB (version 3) using an Adafruit Mono 2.5W Class D Audio Amplifier (PAM8302), which has a much smaller footprint and height than the previous self-assembly amplifier kit I was using.

Adafruit Mono 2.5W Class D Audio Amplifier (PAM8302)
Adafruit Mono 2.5W Class D Audio Amplifier (PAM8302)
Adafruit Mono 2.5W Class D Audio Amplifier (PAM8302), speaker and PCB
Adafruit Mono 2.5W Class D Audio Amplifier (PAM8302), speaker and PCB
Adafruit Mono 2.5W Class D Audio Amplifier (PAM8302), speaker and PCB in action

Printed Circuit Boards

Finally had the chance to work out how to create the files for the PCB to go inside the Space Rocks, using KiCAD, and with much help from @cunabula.

The files have now been sent away to be printed, and I eagerly await being able to test them in situ in a few weeks’ time.

ex-XBees

So…it seems that the combination of XBee RSSI data and the Mozzi synth can only produce intermittent or pulsing sound and doesn’t allow for constant tones, as witnessed by the following video demos. All the data that has to be sent from Arduino to the XBee in order to get it to send and receive packets is causing the audio to stutter.

To get the tones required for the final piece, the circuits will need to be created using SX1278 LoRa modules instead. These will connect the four Space Rocks via an additional transmitter, and based around this circuit:

This should guarantee that the Mozzi synths can play continuous tones rather than interrupted pulses. Although I’ll now need to find a way to fit 4+”  433MHz antennaes into the Space Rocks too.

433MHz antennae
433MHz antennae