First, apologies if this has been answered before... I searched the forum but couldn't find a satisfactory answer...I did see emdee's heliostat project and still not sure...
So, I'm working on a single axis solar tracker using a satellite linear actuator with reed switch and built-in limit switches.
The idea is to have an RTC hooked up and an algorithm/ lookup table to know solar position to control the linear actuator.
I'm trying to figure out the best/most robust option of control and have come through different opinions:
- Use the Official Motor Control Shield Rev3
- Use a simple TIP 12X H-bridge and connect the reed to an interrupt to have feedback.
- Use a combination of DPDT SPST relays and again connect the reed to interrupt.
I have read posts about the Motor Control Shield Rev3 saying that it easily overheats at high currents (close to the 2A max) and although I assume the "normal" current will be below 1.5A (see curve at the bottom of website link) most of the time, I'm concerned about it shutting down or getting damaged especially during the long morning west-to-east movement. (I'm not concerned about thermal shutdown in case of high winds as I would prefer the array to be stationary anyway)
In the other two cases I'm a little bit concerned about reliability in terms of properly handling startup currents, limit conditions, thermal protection...
In case I don't need sophisticated control (speed,PWM) but I do need to know actuator position what control would you suggest for this arrangement?
thanks in advance