Originally Posted by
Raleighcopter
hey chris. i read the new code you sent. i realize it is working for you at the moment but you're doing some things i did with the solenoid controller in its evolution.
i know you're using the air pump witout a solenoid at the moment. you're using 215 steps for the pump output. is there a reason you're not utilizing more steps?
have you tested to see how many steps are possible?
do you have plans to add air temperature and pressure compensation? if so, you're going to want more steps.
On your picture Dave - Looks like you got the right style - There are tons of versions and it seems like many different manufactures too.
I am aware if the step restriction but for the development I just wanted to keep it simple - Because this is a less "precise" form of mixture control. My testing ( Viable DC power to pressure checks) showed a very corse but repeatable relationship. I decided to use the basic 0-255 PWM generation in the MPU. More steps might be better but I don't know if they would be required for the basic "tank pressure" with the solenoid setup. As you point out it might help when its used alone without the solenoid.
Here is what I know from testing - Bench only - a 10% output bias on the pump pulse width gets a "fine tuning" type response. I know with the solenoid this is a dramatic change. 10% on the pump is more line 1% on the solenoid.
Programming MPU's is a bit of black magic to me and I tend to keep stuff a simple as possible - The Timer functions and porting quickly go over my head. My code is usually snippets of simple code that I just mange to get to work together. Im sure you will be able to come up with much better. I do think if we can tie this all together into one board and package it right it will be a good setup.