Fixed the Wheels

I doubled up the adapter hubs (before):

And after:

This side required a card-board washer between the hubs but the other side was fine.

Test Drive

I took the testbed for a test drive. I am pretty impressed with these motors and wheels. They had no problem going over grass and rough surfaces.

Unfortunately they will not take the weight of the full size Dalek.

The WiFi range is about 20 m. I will have have to add an "out of range check" and shut the testbed when out of range.

I had another look at the hub adapters for the full-size Dalek and I think I am better off using these with a custom wheel (rather than the roller-blade wheels).

Software

Well "ticker" works with ESP-12E so I will rebuild the code to suit.

Hardware

I have also looked at using a PCF8574 (an 8 bit I2C port expander) to expand the available ports. That looks good too. But to use it I have to rebuild the hardware from the ground up. Basically add the PCF8574 to the ESP-12E first, then drive the DRV8825s off that. So it will be strip-board to get going and perhaps a PCB if I like it.

AlanX