MD22 and failsafe

[mike87162]

Hi,

I've been using an MD22 in analog ( 0V - 2.5V - 5V) mode connected to my SX28AC based controller. A problem I quickly discovered is that if my controller fails, then my controller is either putting out 0V or 5V & the MD22 is telling the motors to go full forward or reverse. This is not ideal.

So I'm thinking of re-programming my controller to output R/C signals, but I've never used this mode, so before I invest time in reworking the code and PCB I have a few questions about R/C mode.

1) On power-up what does the MD22 do ? Are the motors powered off until it receives the first pulse ?
2) I assume the MD22 only times the length of the high pulse, is this correct ?
3) If I do NOT use the mode with a timeout, and I stop sending pulses, will the motors continue to run at the same speed ? i.e. can I get away with only sending a pulse when I want to change motor speed ?

Thanks

[chris]

Hi Mike,

1, The MD22 initialises with the motors not being powered
2, The MD22 only measures the period of the high pulse, although the pulses need to be sent one at a time (as RC controllers do!)
3, Yes, with no timeout the motors will continue to travel at the same speed and direction until commanded otherwise.

[mike87162]

Excellent. Thank you.