Hello,
first of all thank you for your amazing work!
I ran for 8 months on one of your projects, nano+easydriver+nema17
Now i felt it was the time for an upgrade for my rc8, and offered me a nema17 PG27 as well as try a drv8825 board that seems pretty interesting.
I tried to implement it without the PCB board option in minimal config and at the moment i've already burnt two nano.
Before going on for a third , i thought to ask you for help.
The trouble comes from the RESET-SLEEP wiring to the 5v nano pin i think
If i understood correctly this will bring logical supply to the driver from the arduino.
I tried two ways, RESET-SLEEP shorted and connected directly to 5v
And, reading Pololu page about the driver, i also tried to short SLEEP-RESET but connect FAULT to 5v on nano. I've also tried with ENABLE disconnected as Pololu says it's not mandatory cause default is enable. nano GND connected to DRV GND.
Before connecting to 5v, all works fine except that the driver doesnt move, i think this is the correct behaviour.
Once connected to 5v nano burns or start to malfunction cause of permanent damage.
I've seen a strange behaviour, not expected, just before nano failure the second time i tried. The nano wasnt powered by usb, but once restarted with 5v connected it was lit on as if it was powered by the driver that is connected to 12v.
I can give eventually more info if needed.
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
Hi Alessandro
Please email me direct so we can figure this out. Reset/Sleep should be tied to +5V from the Nano, Enable is used to turn coil power output of the DRV8825 On/Off. This follows the Pololu guidelines for the drv8825. I have attached the PDF which shows this on Page 2.
"The chip has three different inputs for controlling its power states: RESET, SLEEP, and ENBL. For details about these power states, see the datasheet. Please note that the driver pulls the SLEEP pin low through an internal 1MΩ pull-down resistor, and it pulls theRESET and ENBL pins low through internal 100kΩ pull-down resistors. These default RESET and SLEEP states are ones that prevent the driver from operating; both of these pins must be high to enable the driver (they can be connected directly to a logic “high” voltage between 2.2 and 5.25 V, or they can be dynamically controlled via connections to digital outputs of an MCU). The default state of theENBL pin is to enable the driver, so this pin can be left disconnected."
So from this RESET and SLEEP must be HIGH for the drv8825 to work, and enable can be either off or on (myFocuserPro uses the enable pin to turn on and off the driver outputs because that is what ENable does.
If the nano is frying quickly when 5V is connected it must mean that something is drawing too much current from the nano. I know RESET/SLEEP are tied to 5V of the nano, but the pololu docs clearly state that the pins are to be driven high and that on the polulo side this is via 1M / 100K pull down resistors - so that could not fry the Nano, there has to be something else causing this.
If you email me we can work on finding out what the issue is. I will need
- what layout you are using for the board (link would be great or just send me the layout file)
- what arduino firmware file you are using
- pictures of the top and botton sides of your board if you can provide them
Hello Robert,
Thank you for your mail.
I ll contact you as soon as I have all infos you ask.
At the moment I'm waiting for new parts to arrive to replace the fried ones.
Alex
Thanks again for your help
Il 12/feb/2016 22:03, "brown_rb" brownrb@users.sf.net ha scritto:
Hi Alessandro
Please email me direct so we can figure this out. Reset/Sleep should be
tied to +5V from the Nano, Enable is used to turn coil power output of the
DRV8825 On/Off. This follows the Pololu guidelines for the drv8825. I have
attached the PDF which shows this on Page 2.
"The chip has three different inputs for controlling its power states:
RESET, SLEEP, and ENBL. For details about these power states, see the
datasheet. Please note that the driver pulls the SLEEP pin low through an
internal 1MΩ pull-down resistor, and it pulls theRESET and ENBL pins low
through internal 100kΩ pull-down resistors. These default RESET and SLEEP
states are ones that prevent the driver from operating; both of these pins
must be high to enable the driver (they can be connected directly to a
logic “high” voltage between 2.2 and 5.25 V, or they can be dynamically
controlled via connections to digital outputs of an MCU). The default state
of theENBL pin is to enable the driver, so this pin can be left
disconnected."
So from this RESET and SLEEP must be HIGH for the drv8825 to work, and
enable can be either off or on (myFocuserPro uses the enable pin to turn on
and off the driver outputs because that is what ENable does.
If the nano is frying quickly when 5V is connected it must mean that
something is drawing too much current from the nano. I know RESET/SLEEP are
tied to 5V of the nano, but the pololu docs clearly state that the pins are
to be driven high and that on the polulo side this is via 1M / 100K pull
down resistors - so that could not fry the Nano, there has to be something
else causing this.
If you email me we can work on finding out what the issue is. I will need
- what layout you are using for the board (link would be great or just
send me the layout file)
- what arduino firmware file you are using
- pictures of the top and botton sides of your board if you can provide
them
Hello
Yes.
(actually I m in standby with that and using successfully uno+l293d i had
spare, having some issues with torque in half stepping, but not tested
fully, clear skies too rares, for the rest it s really easy to setup)
Il 13/mar/2016 19:25, "brown_rb" brownrb@users.sf.net ha scritto:
You are using a separate 12V connected to VMOT/GND of the drv8825 to power
the stepper?
Hello,
first of all thank you for your amazing work!
I ran for 8 months on one of your projects, nano+easydriver+nema17
Now i felt it was the time for an upgrade for my rc8, and offered me a nema17 PG27 as well as try a drv8825 board that seems pretty interesting.
I tried to implement it without the PCB board option in minimal config and at the moment i've already burnt two nano.
Before going on for a third , i thought to ask you for help.
The trouble comes from the RESET-SLEEP wiring to the 5v nano pin i think
If i understood correctly this will bring logical supply to the driver from the arduino.
I tried two ways, RESET-SLEEP shorted and connected directly to 5v
And, reading Pololu page about the driver, i also tried to short SLEEP-RESET but connect FAULT to 5v on nano. I've also tried with ENABLE disconnected as Pololu says it's not mandatory cause default is enable. nano GND connected to DRV GND.
Before connecting to 5v, all works fine except that the driver doesnt move, i think this is the correct behaviour.
Once connected to 5v nano burns or start to malfunction cause of permanent damage.
I've seen a strange behaviour, not expected, just before nano failure the second time i tried. The nano wasnt powered by usb, but once restarted with 5v connected it was lit on as if it was powered by the driver that is connected to 12v.
I can give eventually more info if needed.
Hi Alessandro
Please email me direct so we can figure this out. Reset/Sleep should be tied to +5V from the Nano, Enable is used to turn coil power output of the DRV8825 On/Off. This follows the Pololu guidelines for the drv8825. I have attached the PDF which shows this on Page 2.
"The chip has three different inputs for controlling its power states: RESET, SLEEP, and ENBL. For details about these power states, see the datasheet. Please note that the driver pulls the SLEEP pin low through an internal 1MΩ pull-down resistor, and it pulls theRESET and ENBL pins low through internal 100kΩ pull-down resistors. These default RESET and SLEEP states are ones that prevent the driver from operating; both of these pins must be high to enable the driver (they can be connected directly to a logic “high” voltage between 2.2 and 5.25 V, or they can be dynamically controlled via connections to digital outputs of an MCU). The default state of theENBL pin is to enable the driver, so this pin can be left disconnected."
So from this RESET and SLEEP must be HIGH for the drv8825 to work, and enable can be either off or on (myFocuserPro uses the enable pin to turn on and off the driver outputs because that is what ENable does.
If the nano is frying quickly when 5V is connected it must mean that something is drawing too much current from the nano. I know RESET/SLEEP are tied to 5V of the nano, but the pololu docs clearly state that the pins are to be driven high and that on the polulo side this is via 1M / 100K pull down resistors - so that could not fry the Nano, there has to be something else causing this.
If you email me we can work on finding out what the issue is. I will need
- what layout you are using for the board (link would be great or just send me the layout file)
- what arduino firmware file you are using
- pictures of the top and botton sides of your board if you can provide them
Cheers
Robert
Hello Robert,
Thank you for your mail.
I ll contact you as soon as I have all infos you ask.
At the moment I'm waiting for new parts to arrive to replace the fried ones.
Alex
Thanks again for your help
Il 12/feb/2016 22:03, "brown_rb" brownrb@users.sf.net ha scritto:
You are using a separate 12V connected to VMOT/GND of the drv8825 to power the stepper?
Hello
Yes.
(actually I m in standby with that and using successfully uno+l293d i had
spare, having some issues with torque in half stepping, but not tested
fully, clear skies too rares, for the rest it s really easy to setup)
Il 13/mar/2016 19:25, "brown_rb" brownrb@users.sf.net ha scritto:
Hi Alessandro
All is good now?
Robert