If you need your robot to sense nearby objects I would not use old technology acoustic Pingers, but these instead ($5 each):
I have a 120 volts 3 amp relays.
I want to use them with 220 volts at 1 amp instead of 120 volts 3 amp.
Is there any solution to program propeller with android? USB otg and ftdi aren't problems. The only thing what is missing: compiler+uploader.
I am having trouble getting the BS2 to read and display ASCII code from a sensor. any Suggestions