HB-25 speed up or down

dbj

I have been looking for some examples of controlling the speed of the HB-25 speed control that I just got.What I would like to do is control the speed with· two push buttons one to increase rpm and the other to decrease, I·will be using this on my waste oil·heater to control oil pump speed. Also would like to monitor·the rpm with magnetic sensor so that I can display Data·with a serial BPI-216 LCD module, Show the·actual rpm and make it adapt. As the heater runs almost 600 hours a winter and burns almost 750 gallons of waste oil the filter tends to get·restricted after 200 to 300 hours,·so if I new how much offset was being used to maintain a steady rpm I would know when the filter was restricting the inlet flow of the pump.·Also thought about a vacuum sensor?·I have some·Derivative Algorithm code that someone wrote,·it is very interesting how this code works, nice·work! ·It would be nice to incorporate this feature in my oil flow control. Well thanks to all you·out there banging out code, its nice to have such a great Forum. Thanks·also to Parallax, ·David

Post Edited (dbj) : 9/10/2007 5:02:54 AM GMT

dbj

Can you use single pot to control both lcd bar graph and motor speed or should I use dual pot? Have not yet built on breadboard just trying to get to a starting place. going to get cold soon!!· Thanks Dave

Paul Sr.

Sure, a single pot will do fine. That's the beauty of using a uProcessor! You "read" the value of the pot, then do however many things your hardware will allow!

You should breadboard it and give it a whirl!

dbj

How do you control HB-25 from the VAR· X· word ?· Lcd works but no HB-25 . I dont understand the concept, some of this code is from project by Tom J. Sisk , very cool !! This is some of the only code that I have seen that controls the speed of the HB-25 threw a pot useing RCTIME command. Thanks For the Help Dave

Post Edited (dbj) : 9/14/2007 3:00:09 AM GMT

Beau Schwabe

dbj,

Have you seen this thread?
http://forums.parallax.com/showthread.php?p=629063

This describes a ratio metric approach to reading a POT through RCTIME that might be easier to incorporate into setting the pulse width for an HB-25
An added benefit of ratio metric reading is that any temperature drift that may affect the returned value is minimized or mathematically canceled out.

The example in the thread provides a 0 to 100 value that indicates a percent for the output. This could easily be changed to whatever is appropriate for your application.

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Beau Schwabe

IC Layout Engineer
Parallax, Inc.

dbj

I would like to know why the LCD display flikers just a little bit and is there any way to make better, also
·would like to change the bar graph to go from right to left insted of·left to right ?

Post Edited (dbj) : 9/15/2007 8:24:44 AM GMT