motors not moving Gecko 201x

[silyavski]

Hi,
my old BOB stopped working so while am waiting for the repair i bought a Wantai motor BOB with PWM. So connected it and all leds ok, motor pins active low ok, also enabled the common pins for the steppers. Everything wired ok, green light on Geckos,motors power up. The problem is that nothing moves. First i thought a Mach3 setting is not ok/ i am still not sure/.
With the original board in the output pins tab in Mach3 all the motor output pins and all the common pins were enabled as outputs and with active low enabled, what i dont understand is that the port is set to 0, but i followed this, any way, changing it to one did not help. so i left it like this

With multimeter i measured the 3 output pins with the red wire and the black to some ground on the BOB.
step +3.7v
dir +3.7v , when jogged around goes to 0
common +3.7v

is this ok as what should be if Mach3 is configured properly and is this voltage enough or should be 4.5 to 5v to drive the geckos

The board needs 12v and i tested it with 2 4a adapters 220 to 12v but the voltage is still the same. And as you can suppose, no documentation on this one. i have another thread asking other questions about this board

[silyavski]

i did some measuring with the multimeter, it seems that before the leds the signal is 5v and after the leds drops to 3.5v
meanwhile bought a stepper driver tester from ebay, as i am spending too much time with things like this
what will happen if i disconnect the enable from the board and plug all 3 of them directly to some 5v output or to a small external power supply, will it do the trick? Or its not a good idea?

[silyavski]

No body has this BOB? i still can not make it work although everything seems right

[doorknob]

I do not have this BOB, but wanted to mention that the Gecko G201X description at G201X 10 Microstep Digital Drive says, "STEP and DIRECTION is +3.3VDC and +5VDC compatible at 2.5mA".

So, if you are measuring 3.3 volts or more on the DIR pin, that would seem to be sufficient voltage.

However, my interpretation of Gecko's description is that it is also looking for 2.5 mA of current from the BOB output (but maybe you should verify that interpretation with Gecko support.)

Is it possible that the BOB circuitry is designed to sink current, but not to source current? For example, if the output pins of the BOB are pulled up via a 4.7K ohm resistor, then the output will probably not be able to source anywhere near 2.5 mA. If the BOB had good documentation, it would state whether or not it was designed to source current.

Note: I have not tried the following test, so I make no guarantees about it, but I believe that it will be a safe test:

One way to test that might be to temporarily put a 1000 ohm resistor between one of the DIR outputs and ground (with the BOB disconnected from the Gecko inputs), and measure the voltage across the resistor with your multimeter (when that pin should be putting out 3.3 volts). From that reading, you should be able to figure out if the BOB can source a few mA of current (if the voltage still reads close to 3.3 volts), or whether that output is not designed to source much current (for example, if the voltage drops to some lower value).

[silyavski]

thanks,
maybe sth like this is happening.i will check this today after work. i remember there were some resistors at the output and also the fact thet before the led its 5v and after the led its 3.5v
so if this is the case what can be done? i can leave it for some other machine, but which drives work like this?