Asked
Resolved Resolved by DJ Sures!

Power On Sequence

My question relates to powering on the robot.  I am designing the power supply to my Inmoov robot and I will be using the LattePanda PC along with EZB V4's and IoTiny.   My plan was to have my LattePanda auto boot when power is applied to it and start ARC and load a project and Init Script.  At the same time the power is turned on to the LattePanda power will be supplied to the EZB's and IoTiny NO power will be supplied to the servos before the init script can connect to the EZB's and set the servo limits and such.   Once that process has completed that is when I want to apply power to the servos by turning on another switch.  My question is can this be done or do I need to take a different approach?

What would be really nice is if as part of the init script I could use a relay to switch on the servo power automatically after the servo settings.


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Synthiam
#1  

The kind of servos you’re using do not require bidirectional communication. So they can be powered on when ever you decide. An init script Is a good idea.

#2  

Ok DJ, Thanks for the conformation!

#3   — Edited

So why is it that EZb power on , my digital ports 14-16 are automatically always on ,as a pwm controlling my star light driver board. I had to write in the init script turn off D14 which it does. Only thing is the hand blaster weapon light always starts on pointing at the floor like a flashlight until init sequence shuts off? Edit...ya not sure why that happens as I had a relay before that was always off at Ez start.The driver board is wired same as a servo so ya weird....there could be some servo profile somewhere that calls d14 to "90" at start up ,need to check that.

#4  

Hi Smiller29,  I do exactly that with on big servo in my full sized B9 robot. The bubble lifter servo was jumping badly if powered on before servo limits, speed and position were set. I set all these values in my INT Script. I used a relay to turn the power on that is closed after the values are set in the INT Script. It worked really well.

I'm my case I built a relay switch out of a transistor as the servo would pull less amps then the transistor was rated for. Sounds like you are going to run all your servos through a relay. You would probably benefit from a bigger 12v automotive relay. These usually can handle 20, 30, 40 amps. You could even mount and use more then one relay and run different power circuits to different sets of servos. This would greatly aid you in properly banking and fusing the circuits feeding different sets of servos. Doing this also aids you in troubleshooting and protecting.

#5  

Thanks Dave I may want to talk more about this as I get closer in my build.