Gentlemen, I've decided to use both the "cog" mechanical approach for the board I already have and make a new board with 41 steppers.
I'll use the cheap 28BYJ steppers. As mentioned before, it seems, I have to use shift registers. I did some "home work" on them, tried to find tutorials but I'm back to square one.
Can you pls guide me trough type of shift register / port expander to use ?
For example I read MCP23017 with I2C or MCP23S17 which uses the SPI interface that operates at 10MHz , much faster than I2c. Or 74HC595 or TPIC6B595. These are all over my rookie head and I don't know which one to use.
Can I use A4988 drivers with mod 28BYJ's with these shift registers? Or use their old ULN2003 ?
I'd like to avoid having to add transistors capacitors etc etc.
Pls remember I need all servos to turn together, at slow speed, and only clock wise. Synch is the most important aspect !
Is it possible to drive all the steppers with one signal pin from Arduino ? if yes, how ?
Thank you.