And then you can use the dedicated PCA9685PW chip with 16 channels, 12-bit resolution, cheap and very reliable. Also the PCA9956BTW at 24 channels @ 8 bit.
Hah, just solved it :)
since I have output transistors, previously I was feeding their bases with output from MCU
Now I will feed their emitters via MCU, connect all bases together and connect them...
Darrels documentation says
In order to increase the resolution to 10 bits the LSB would need to be 1/4 of its current length meaning you'd need the PIC to run at 192MHz. Or you'd need to reduce the...
I'm using MIBAM because with 64mhz PIC18 CPU, I can have 48 independent PWM channels. But they're 8 bit. I want 48 channels with 9 or 10 bits resolution (12 - preferable) :)
Unfortunately, there are no PIC chips with like 8-16-32 independent PWM outputs.
Sure, there are chips like LT8500, with 48 channel PWM output, but they're way too expensive...
So maybe bitbang isn't the right word, but I am wondering if anyone has attempted USB communication on a chip without integrated USB functionality. I'm aware chips like the 18F2550 include that...
Published on - 2nd July 2010 16:12
Number of Views: 12074
I have been thinking for a while, how to put togeter a simple microstepper controller without using a ready made commercial driver.
At the end, I came up with this simple project capable to drive unipolar stepper motor in three different modes
FULL STEP
HALF STEP
MICRO STEP
The Pic micro used in this work is a Pic 16F628 a powerfull small micro with PWM capability. With this MCU plus a 74HC04 and a74HC86 the controller will produce 20 microsteps out of a nominal motor step.
An additional improvement of this controller, is the capability to accept travel commands of 24 Bits, wich gives to the user the possibility to send positioning profile of over 16 millions steps.
Controller accept commands via TTL serial port @ 9600,n,8,1 and return an (Ack) once the positioning profile has been completed.
Download the zipped MicroStepper.zip file which contains schematic + software + user manual
Also attached is a simple stepper controller example called Stepper_MK2.zip
Re: Increasing resolution of DTs MIBAM library?
And then you can use the dedicated PCA9685PW chip with 16 channels, 12-bit resolution, cheap and very reliable. Also the PCA9956BTW at 24 channels @ 8 bit.
Ioannis Yesterday, 15:54Ioannis