search

ambrop72 / aprinter

3D printer firmware written in C++
Other
143 stars 42 forks source link

feature request : Fan's parameters #11

Closed a0s closed 10 years ago

a0s commented 10 years ago

I trying to connect small fan to my ramps-fd. In accordance with the firmware, I connect it to the D12 (ramps-fd datascheet, last page). But the fan does not move, only trembles with any M106 Sx (from S0 to S255). I try to change FanPulseInterval without result. The fan is not broken and works fine from the constant current source 12V. I think linear (from 0% to 100% of period) PWM-control is not the best idea for my fan. I need some offset parameter. Fan PWM I want to set T and offset in seconds manually. Main is Sx parameter of M106 command.

ambrop72 commented 10 years ago

The current implementation will do interrupt based PWM. M106 S0 should be off and S255 should be fully on. If your fan doesn't turn fully on at S255, something is wrong. Have you tried if the logic itself works, not the fan, e.g. by hooking up a LED or scope to the digital pin (possibly try another pin)?

a0s commented 10 years ago

Yes, it was my mistake. I tested it on LED and received the expected result. I found two reasons why thats not working. 1) Friction. The fan is not new. 2) Polarity. It plays a role in my case. Although I first heard about this for simple fan.