SLA7078 unable to make it work at all.
metron9
Posts: 1,100
Attached is the datasheet·I am using to connect this stepper driver chip.
I have tested for hours but no resonse.I do not understand the two Sense pins, Sense A and Sense B
It looks as if they are just outputs to read if you want to and don't need to be connected.
I also don't understand the difference between the Asynchronous PWm operation (low level set on the Sync pin) and Synchronous PWM operation (Sync pin set high)
initially I have the following pins set as follows
M1,M2,M3 = LOW· (mode 8)
Sync is tied LOW
I have an 8 wire stepper motor and I have the motor wired as unipolar, 4 ends going to the 4 outputs pins (1/2,3/4, 20/21,22/23) And the other 4 wires all going to the motor Positive supply voltage (14V DC)
I have a regulator feeding the SLA7078 and the Atmel chip.
Pin 13 Ref is connected to the resistor divider and set at 0.390 VDC
The programming pulses the reset line for the required 2us and waits the required 5us
The clock is pulsed high for 3 mS and then low for 50mS in a loop about 20 clock pulses per second.
pin 12 is ground, pin 14 VDD is regulated 5VDC pin 11 VBB is at motor supply (14VDC)
pin 6 Mo is not connected. is this an output pin that gives feedback every half step?
pin 16 is tied low (rforward reverse switch input)
So i am baffeled with no response from the chip. What do i need to try?
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Think Inside the box first and if that doesn't work..
Re-arrange what's inside the box then...
Think outside the BOX!
I have tested for hours but no resonse.I do not understand the two Sense pins, Sense A and Sense B
It looks as if they are just outputs to read if you want to and don't need to be connected.
I also don't understand the difference between the Asynchronous PWm operation (low level set on the Sync pin) and Synchronous PWM operation (Sync pin set high)
initially I have the following pins set as follows
M1,M2,M3 = LOW· (mode 8)
Sync is tied LOW
I have an 8 wire stepper motor and I have the motor wired as unipolar, 4 ends going to the 4 outputs pins (1/2,3/4, 20/21,22/23) And the other 4 wires all going to the motor Positive supply voltage (14V DC)
I have a regulator feeding the SLA7078 and the Atmel chip.
Pin 13 Ref is connected to the resistor divider and set at 0.390 VDC
The programming pulses the reset line for the required 2us and waits the required 5us
The clock is pulsed high for 3 mS and then low for 50mS in a loop about 20 clock pulses per second.
pin 12 is ground, pin 14 VDD is regulated 5VDC pin 11 VBB is at motor supply (14VDC)
pin 6 Mo is not connected. is this an output pin that gives feedback every half step?
pin 16 is tied low (rforward reverse switch input)
So i am baffeled with no response from the chip. What do i need to try?
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Think Inside the box first and if that doesn't work..
Re-arrange what's inside the box then...
Think outside the BOX!
pdf
522K
432 x 324 - 87K
Comments
I want to thank Dave at Hobbycnc.com for his help on this. Whthout this kind of help I may have given up on trying.
In his first response to my ask for help he wrote this:
Then after a very long email describing why it was important I received this. So I decided to continue trying to figure it out on my own. Now I can get on to other things and know if I ever need to use the SLA series chips I will understand how to use them.
Running at 1/16th steps (3,200 steps per revolution) Amazing as there is no load and no problem with resonence at 11 KHZ step rate about 206 rpm
http://www.siliconcoder.com/sla7078/sla7078.html
Oh the problem was the adaptor board, two of the pins were not connected to the header pins, I did have it connected correctly, just my soldering skill was bad.
The next step is to figure out how Gecko drives change from microstepping to full stepping on the fly, I have not yet got it through my head the algorythm one would use to acheave this but as yet I have only thought about it in the abstract. Soon I may apply some thought to it.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Think Inside the box first and if that doesn't work..
Re-arrange what's inside the box then...
Think outside the BOX!