Glad I could help On Thu, Jan 21, 2016 at 12:42 PM, Jake <k1llfre...@hotmail.co.uk> wrote:
> Thanks John, I had to wiggle the % around. I think I ended up with 10 and > 3, but it spins the same speed both ways. Thanks :) > > On 19/01/16 19:18, John Duncan wrote: > > You have a cycle that is 21.7ms (t) in length, with 1.7ms on and 20ms off. > The frequency is 1/t or 46Hz. The duty cycle is the amount of time on > divided by the length of the cycle, 1.7/21.7 or 8%. I'm rounding to the > nearest integers. > > On Tue, Jan 19, 2016 at 1:53 PM, Jake <k1llfre...@hotmail.co.uk> wrote: > >> I can't test those numbers as I don't have a power supply at home. I'm >> curious how your work out hte duty cycle as a percentage? >> Thanks. >> >> On 19/01/16 18:32, John Duncan wrote: >> >> Just a guess, you probably need to consider the whole 21.7ms or 21.3ms to >> be your period (46Hz or 47Hz) and then your duty cycle will be 8% or 6% >> respectively. >> >> On Tue, Jan 19, 2016 at 10:32 AM, J B < <k1llfre...@hotmail.co.uk> >> k1llfre...@hotmail.co.uk> wrote: >> >>> I'm trying to use the PWM module to control a parallax servo I >>> purchased. I'm trying to get it to spin both ways as I need it for a >>> project, I have tried to spin the servo both clockwise and anti clockwise >>> but I do not know how to set a 20ms gap between each pulse, I need 1.7ms to >>> go anti clockwise with a 20ms gap and 1.3ms with a 20ms gap to spin >>> clockwise. I've converted the ms into frequency but it doesn't change the >>> direction. When I plug the data cable into any pin on the entire board the >>> servo spins clockwise, even when plugged into PWM0 and (pwm-stop 0) being >>> called. >>> >>> On another point is there a dedicated ground pin? I plugged the PWM0 >>> port into an oscilloscope and it was littered with static, according to my >>> electrical engineering tutor there is a bad ground and I need to earth it. >>> >>> Another another point, my LCD display still doesn't work and I don't >>> know what to do about it. >>> >>> The attachment is a datasheet for the servo I bought. >>> Thanks. >>> >> >> >> >> -- >> John Duncan >> >> >> > > > -- > John Duncan > > > -- John Duncan