Maybe someone can shed some light on this. I'm running two stepper motors using an 20M2 via two ULN2003 boards. You know the ones with the LED's' and connectors.
I'm controlling the steppers by doing in a typical "high b.0: low b.1: high b.2: high b3 then a pause. This is done for every step. I slowed the program down with long pauses between steps, so I could see what what causing the stepper not to run smoothly. It appears one or two of the LED's on the board are lighting up very dim and only for a brief time when they shouldn't be. I think this is causing the stepper to run rough. What could cause this, or is this inherent when using the high/low to run a steppers?
I'm not running the steppers at the same time, so only four outputs are being used. The problem exists no matter what ULN2003 board I use or stepper. The steppers are the common, geared ones (28YBJ-48) that are usually sold with the ULN2003 boards.
Also, I was going to originally use binary to control the output's which is fine, if you are going to run two steppers the exact same distance at the same time, since it appears you can't separate the B.0 thu B.7 into two groups of four. You have to control all eight bits at the same time, which means if you write 00001111, to control one stepper the stepper connected to the 0000 outputs will not move, so it's all eight bits in the command or nothing. That's why I used the high/low system.
However, since I'll only be running one stepper at a time. I guess I could use the binary control system. Who cares if the other steppers control lines are zero's (off) when it's not being run anyways.
It does appear you could run two steppers at the same time with two different steps and pauses by using a 28X or a 28X1. However, you run into the same problem having to use eight outputs for each stepper. The 28X and X1 simply gives you more outputs.
Attached is the program. I'll be connecting switches to control; auto/man, jog, direction, stepper selection, full/half step mode. I will also attempt to use C.1 and C.0
connected to a pot. to set the distance; where C.1 (adc input x 200 = W6), this should give me up to 51,000 steps max. since 255 x 200= 51,000.
The speed (pause between steps) would be C.0 (adc input x (say 50 or whatever) = W8 (don't want the pauses to be too long).
I haven't written the jog portion yet, and haven't checked all the sequence's because I ran into the above problem.
This is not a big deal, as I'm only doing this in order to put some schematics and some programs to operate steppers, on the Forum, for learning purposes. As you can see I
can use some learning myself.
I'm controlling the steppers by doing in a typical "high b.0: low b.1: high b.2: high b3 then a pause. This is done for every step. I slowed the program down with long pauses between steps, so I could see what what causing the stepper not to run smoothly. It appears one or two of the LED's on the board are lighting up very dim and only for a brief time when they shouldn't be. I think this is causing the stepper to run rough. What could cause this, or is this inherent when using the high/low to run a steppers?
I'm not running the steppers at the same time, so only four outputs are being used. The problem exists no matter what ULN2003 board I use or stepper. The steppers are the common, geared ones (28YBJ-48) that are usually sold with the ULN2003 boards.
Also, I was going to originally use binary to control the output's which is fine, if you are going to run two steppers the exact same distance at the same time, since it appears you can't separate the B.0 thu B.7 into two groups of four. You have to control all eight bits at the same time, which means if you write 00001111, to control one stepper the stepper connected to the 0000 outputs will not move, so it's all eight bits in the command or nothing. That's why I used the high/low system.
However, since I'll only be running one stepper at a time. I guess I could use the binary control system. Who cares if the other steppers control lines are zero's (off) when it's not being run anyways.
It does appear you could run two steppers at the same time with two different steps and pauses by using a 28X or a 28X1. However, you run into the same problem having to use eight outputs for each stepper. The 28X and X1 simply gives you more outputs.
Attached is the program. I'll be connecting switches to control; auto/man, jog, direction, stepper selection, full/half step mode. I will also attempt to use C.1 and C.0
connected to a pot. to set the distance; where C.1 (adc input x 200 = W6), this should give me up to 51,000 steps max. since 255 x 200= 51,000.
The speed (pause between steps) would be C.0 (adc input x (say 50 or whatever) = W8 (don't want the pauses to be too long).
I haven't written the jog portion yet, and haven't checked all the sequence's because I ran into the above problem.
This is not a big deal, as I'm only doing this in order to put some schematics and some programs to operate steppers, on the Forum, for learning purposes. As you can see I
can use some learning myself.
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