I am having a problem with the SD21 servo control board. When I power it up all the connected servos appear to default to their mid position. This is fine except two servos which I want to default to an end position. On power up these two servos move to their mid position first and then return to their programmed end position some time later.
I thought this was due to writing to the i2c base register (mid position) at the start of my code followed by writing the i2c positive / negative register position some time later in the code. I tried fixing this by writing to the positive / negative register on the line of code immediately after writing to the servo base register but this still does not work.
As a second fix I tried setting the base register value at one end of the servo travel and just using a positive or negative offset to control the servo position. Once again this did not solve the problem.
Does anybody else have any suggestions of what I can try?
I thought this was due to writing to the i2c base register (mid position) at the start of my code followed by writing the i2c positive / negative register position some time later in the code. I tried fixing this by writing to the positive / negative register on the line of code immediately after writing to the servo base register but this still does not work.
As a second fix I tried setting the base register value at one end of the servo travel and just using a positive or negative offset to control the servo position. Once again this did not solve the problem.
Does anybody else have any suggestions of what I can try?