Hi Robert I have recently completed a stripboard build of a full version of a Nano DRV8825 controller with addition of bluetooth module. I am running it with the v265 firmware and everything is working regardingf in the test programs. I just have a small query which I have searched for answers for in your various pdf files. But I am struggling to find an answer for my query. In the test program for running the motor I could alter the ino file to enable microstepping and change the steps/revolution to give a full rotation both clockwise and antclockwise depending on the micro step selcted ie 1/4 stepping 1600 steps per rev 1/8 stepping 3200 steps per rev.
I intend to run my focuser on 1/2 stepping at 800 steps per rev fitted with stepped pulleys with a 3to1 ratio with an option to perhaps go down to 1/4 stepping. This should give me 5 um steps at 1/2 stepping.
while I can follow the programming and changes needed to be made in the test program the understanding of the full program and changes needed are beyond me I'm afraid.
I would therefore be grateful if you could guide me as what changes are needed for 1/4 stepping to be enabled and what has to be changed for the different number of steps/rev.
Thanks in anticipation
Regards
Charles Clark
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Hi Charles
It is important that you determine the correct stepmode, and then set the focuser up accordingly. Not recommended at all that once this is done, you change the step mode. Set it once and then dont change it. Changing it will invalidate the maxsteps and final position as well as 0 or home. Not recommended.
With the DRV8825 steps per revolution is not used at all.
As stepmode is remembered in eeprom, all you need to do is setup the focuser once using the windows app, there is a video on this, set the step mode to 1/2, send it to the controller, write eeprom and it is done. Also set home and maxsteps and it is good to go. From that point on do not change step mode.
Your steps per revolution is a factor of your connection train (gearing), step mode, and stepper motor angle (default steps per rev is 200 per 1.8 degree motor). You do not need to enter this anywhere in the firmware for the drv8825
Regards
Robert
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Hi Robert thanks for your prompt response in pointing me in the right direction. I am using a nema 14 0.9 degree step size giving 400 steps on full stepping 800 steps on half stepping. I am assuming that to work out the max step size it is calculated at say 800 steps x 4.5 turns which would give 3600 steps then if using a 3 to 1 pulley ratio this would give 10800 max step size.
Have i got this right.
Also with the bluetooth module which is hc 06 (slave) the only way i found to get it to work is with thae arduino controller connect up by usb to the windows focuser app (main program) then open up the mini version to connect to the bluetooth usin the coms option in the mini. This works ok but it seems to have to treat the bluetooth connection as a 2nd focuser. This seems to be not very beneficial as you may as well run it from the windows app connected to the usb.
Is this methodology i am using correct or am doing something totall stupid.
Thanks in anticipation and thanks for a great project.
Regards
Charles Clark
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Hi Charles
at half steps, 800 * 4.5 * 3 = 10,800
Yes
Some users have had little success with HC06 and have had to program it with AT commands first to set it to slave mode and 9600. I have never used a HC06.
The normal thing is the focuser is connected to 12V and has an HC05. No usb cable.
The HC05 is paired and generates a com port when installed (sometimes there are two ports - if there are only one works and the other does not)
In the windows app or ascom driver the speed is set to 9600 and the comport to that of the HC05 driver. Then all you need to do is "connect"
To test, program the controller with the Arduino IDE. Some earlier versions the BT is broken and v268 tries to address this. You can also try the test bt code.
In IDE specify com port for BT device and open serial port monitor. Set speed to 9600
If it works you should see/hear controller reboot
Sending :03# should return the firmware version
Sending :00# should return the focuser position
If it works with the serial port monitor it should work with the windows app
Thanks Robert thats great.
I did order an hc05 module on ebay but it appears i have been sent an hc06. It seems that an hc06 is only a slave while an hc05 can either be a master or a slave. As i gather the hc05 has to be set to as a slave. I went ahead with the hc06.
As i say it works in a fashion it does show two com ports but i can only connect it with a usb cable plugged in. If i try to connect via a bluetooth com port they give an error message failing to connect. I don't think i will be spending too much time with this trying to get it to work.
Regards
Charles Clark
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Update on the bluetooth module. This is now working fine without really doing anything to it. I fid find that on switching on an external power supply that whilst getting 8 volt on the lm708 diode it didn't appear to be getting to the vin connection of the nano, hence it and the bluetooth module did not power up. When checking with a meter it beeped and powered up and I was able to connect up com7. I guess I may have a dry joint somewhere on this leg.
I will need to sort this out when I box it all up.
After that it will be a question of how reliable it is.
Stepper motor is working great on 1/4 steps by the way but i did include the micro stepping module that was recommended.
Thanks for all your help and guidance.
Regards
Charles Clark
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To drive the LM7808 regulator that provides voltage to the nano board will require at least 10VDC input. The circuit is designed to have 12VDC input as external power supply. Less and there will be issues.
This is why recommended power to board is 12VDC, which the LM7808 drops down to an acceptable 8V input to VIN of the nano board, which then drops to 5V to power the nano IC.
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Hi Robert I have two focuser controllers both based on the 2017 v11 board. One is a Stripboard build which was working fine I built the second one from a PCB board based on your gerber files. The stepper motor is a NEMA 14 400 step at 0.9 degrees/step and is also geared down via pulleys at 3 to 1. They are set up with the diodes to micro step
The PCB one is working fine but the stripboard version has stopped working for some reason it goes through the motions but the stepper only makes a noise no turning I have tried adjusting the current as per your videos and tried also to alter the delay. Having a light bulb moment I vaguely remember taking the DRV 8825 driver from the stripboard and putting it in the PCB version. Getting some cheap DRV drivers for replacement. I have purchased a Polulo DRV8825 , but while the noise has improved the motor will not turn. The PCB version however runs sweet as a nut. I have completed another PCB board based on the same 2017 v11 schematic but with the micro steeping diodes built into the board, this has a similar problem to the stripboard build.
The Arduino Firmware I have installed in both focuser's is v301 of the DRV8825 H203 firmware and the windows software is v2.4.5.6 Both focusers are using the same stepper motor with the same version of windows. I am loathe to take bits off the one that is working in an attempt to fault find and end up with two that do not work.
Can you advise me what is the difference between a DRV 8825 driver and a DRV8825 H203 version. I have trawled the internet trying to find out but in the UK I can only find DRV 8825 version available.
Also with a 2017 v11 build of focuser running a stepper motor with microstepping based on a DRV8825 driver what version of Arduino firmware and windows software should i be installing.
Many thanks in anticipation
Regard Charles Clark
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Can you advise me what is the difference between a DRV 8825 driver and a DRV8825 H203 version.
This refers to the firmware and PCB versions. The DRV8825 is used on both. The difference refers to the design of the PCB and the Firmware
The DRV8825 PCB means what we originally started with - a stripboard. But after a short while I decided to make a PCB design.
In order to make the tracks look neater and avoid the use of via's on the PCB, I changed the MS1 and MS3 lines over for the new design called DRV8825HW203 PCB. The MS1/MS2/MS3 lines control the microstepping.
That is why the DRVHW203 PCB has its own firmware file, because the pins were changed.
If you try to use a DRV8825 PCB with DRV8825HW203 firmware the microstepping is all wrong
If you try to use a DRV8825HW203 PCB with DRV8825 firmware the microstepping is all wrong
DRV8825 PCB = DRV8825 firmware - OK
DRV8825HW203 PCB = DRV8825HW203 firmware - OK
Also with a 2017 v11 build of focuser running a stepper motor with microstepping based on a DRV8825 driver what version of Arduino firmware and windows software should i be installing.
I do not know because the info you gave is not enough.
In general
If D5 of the Arduino Nano is connected to MS1 pin (next to EN) then it is DRV8825 design.
if D5 of the Arduino Nano is connected to MS3 pin then it is DRV8825HW203 design
a DRV8825 design requires firmware myFP2_DRV8825_310
a DRV8825HW203 design requires firmware myFP2_DRV8825HW203_310
The windows app does not care what type of board or design you are using
Hi Robert,
Thanks for explaining the differences between the DRV8825 HW203 build and the DRV8825.
I have checked out the board that is working which is from a PCB board from your Gerber Files and the pins are as follows :
D5 - MS1
D6 - MS2
D7 - MS3 which equates if I understand correctly to a DRV 8825 design however it is working fine with DRVHW203 301 firmware, which has confused me
The stripboard version that was working is as follows:
D5 - MS3
D6 - MS2
D7 - MS1 which would indicate that it is based on a DRV8825 HW203 version
My modified PCB build with the micro stepping diodes on the board is :
D5 - MS1
D6 - MS2
D7 - MS3
This would indicate a DRV8825 design
I therefore downloaded and installed DRV8825 v310 as suggested
This did not work and for some reason I have lost 12volt supply to the board it appears that the Resettable Polymer fuse has blown compounding the issue.
Any advice would be much appreciated in particular with the HW203 firmware working with what checks out to.be a DRV8825 design board
and what could cause a polymer fuse to blow could it be that the voltage was set too high on the DRV8825 driver.
I have removed the DRV8825 from the board to see if the fuse would reset in case there was a short but no joy
Thanks in anticipation
Regards Charles Clark
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Any advice would be much appreciated in particular with the HW203 firmware working with what checks out to.be a DRV8825 design board
Yes DRV8825HW203 will run on a DRV8825 designed board - BUT, as I said earlier, the step modes are set incorrectly. Let me explain further
This is how microstepping works
Now assume that you have a drv8825 pcb design and incorrectly load the drv8825hw203 firmware.
When a user selects half step mode the firmware sets MS1 HIGH or Logic 1. (100 from MS1 to MS3).
But the firmware swaps over MS1 with MS3 so in effect it is 001 (from MS3 to MS1) which means selecting 1/4 stepmode results in stepmode 16.
=====================================
My modified PCB build with the micro stepping diodes on the board is :
D5 - MS1
D6 - MS2
D7 - MS3
This would indicate a DRV8825 design
I therefore downloaded and installed DRV8825 v310 as suggested
This did not work and for some reason I have lost 12volt supply to the board it appears that the Resettable Polymer fuse has blown compounding the issue. and what could cause a polymer fuse to blow could it be that the voltage was set too high on the DRV8825 driver.
I have removed the DRV8825 from the board to see if the fuse would reset in case there was a short but no joy
Reprogramming drv8825 board with firmware 310 will not blow the fuse, so there is something else going on.
Before we can get into that you need to ensure that the focuserconfig.h file specifies the correct settings for your board or design. In particular enabling the stepper power detect when the hardware circuit for this is not present on the board.
// To enable 12V power detect fot stepper motor, uncomment next line //#define STEPPERPWRDETECT 1
The Polymer fuse resets itself when power is off. It is quick to blow if there is a power issue and the current exceeds 3A. For this to blow then you have a serious SHORT on the board between power and ground. I would start by a good visual inspection of the board and checking for any shorts near GND and the 5V/12V power pins. Another thing that can cause something like this is incorrectly connecting something the wrong way round, like the I2D display or incorrect wiring of the temperature probe.
The LM7808 circuit that provides power to the board from 12V PSU will tolerate a little higher than 12V but not much.
If you have a multimeter, you can try the troubleshooting in the attached zip file, it shows the points to measure and what is expected.
If you do not have a multimeter let me know and I can put comething together on how to troubleshoot the issues without using a multimeter.
Hi Robert,
Many thanks for the Trouble Shooting zip file it is greatly appreciated as well as you clarification on the difference between a DVR8825 and DVR8825 HW203 build.
I have managed to get sorted out with both working with DRV8825 v310 firmware
The one that stopped working and lost 12 volt power was not down to a short but a dodgy header pin ground connection, some how the ground pin had pushed back in the header and was not fully home to the pin on the board.
Sorting this still did not cure it not working but it allowed me to check voltages as described in your trouble shooting file, these were fine.
Checking the 1A, 1B, 2A,2B continuity was giving spurious results so I decided to remove the micro stepping diodes from the Board (I thought I was being clever incorporating them into the main board, big mistake as there was some obvious bad joints because of the solder not taking well to having too many components together taking the heat away from the soldering iron)
Wired this up with no diodes but it still did not work Checked the voltage on the pot on the DRV8825 and there was none, so I had obviously blown it, Replaced it with a cheap one I had and it worked fine.
So Many thanks for your patience and guidance much Appreciated
Regards
Charles Clark
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Hi Robert I have recently completed a stripboard build of a full version of a Nano DRV8825 controller with addition of bluetooth module. I am running it with the v265 firmware and everything is working regardingf in the test programs. I just have a small query which I have searched for answers for in your various pdf files. But I am struggling to find an answer for my query. In the test program for running the motor I could alter the ino file to enable microstepping and change the steps/revolution to give a full rotation both clockwise and antclockwise depending on the micro step selcted ie 1/4 stepping 1600 steps per rev 1/8 stepping 3200 steps per rev.
I intend to run my focuser on 1/2 stepping at 800 steps per rev fitted with stepped pulleys with a 3to1 ratio with an option to perhaps go down to 1/4 stepping. This should give me 5 um steps at 1/2 stepping.
while I can follow the programming and changes needed to be made in the test program the understanding of the full program and changes needed are beyond me I'm afraid.
I would therefore be grateful if you could guide me as what changes are needed for 1/4 stepping to be enabled and what has to be changed for the different number of steps/rev.
Thanks in anticipation
Regards
Charles Clark
Hi Charles
It is important that you determine the correct stepmode, and then set the focuser up accordingly. Not recommended at all that once this is done, you change the step mode. Set it once and then dont change it. Changing it will invalidate the maxsteps and final position as well as 0 or home. Not recommended.
With the DRV8825 steps per revolution is not used at all.
As stepmode is remembered in eeprom, all you need to do is setup the focuser once using the windows app, there is a video on this, set the step mode to 1/2, send it to the controller, write eeprom and it is done. Also set home and maxsteps and it is good to go. From that point on do not change step mode.
Your steps per revolution is a factor of your connection train (gearing), step mode, and stepper motor angle (default steps per rev is 200 per 1.8 degree motor). You do not need to enter this anywhere in the firmware for the drv8825
Regards
Robert
https://www.youtube.com/watch?v=mZmWG_vQ1uM
Hi Robert thanks for your prompt response in pointing me in the right direction. I am using a nema 14 0.9 degree step size giving 400 steps on full stepping 800 steps on half stepping. I am assuming that to work out the max step size it is calculated at say 800 steps x 4.5 turns which would give 3600 steps then if using a 3 to 1 pulley ratio this would give 10800 max step size.
Have i got this right.
Also with the bluetooth module which is hc 06 (slave) the only way i found to get it to work is with thae arduino controller connect up by usb to the windows focuser app (main program) then open up the mini version to connect to the bluetooth usin the coms option in the mini. This works ok but it seems to have to treat the bluetooth connection as a 2nd focuser. This seems to be not very beneficial as you may as well run it from the windows app connected to the usb.
Is this methodology i am using correct or am doing something totall stupid.
Thanks in anticipation and thanks for a great project.
Regards
Charles Clark
Hi Charles
at half steps, 800 * 4.5 * 3 = 10,800
Yes
Some users have had little success with HC06 and have had to program it with AT commands first to set it to slave mode and 9600. I have never used a HC06.
The normal thing is the focuser is connected to 12V and has an HC05. No usb cable.
The HC05 is paired and generates a com port when installed (sometimes there are two ports - if there are only one works and the other does not)
In the windows app or ascom driver the speed is set to 9600 and the comport to that of the HC05 driver. Then all you need to do is "connect"
To test, program the controller with the Arduino IDE. Some earlier versions the BT is broken and v268 tries to address this. You can also try the test bt code.
In IDE specify com port for BT device and open serial port monitor. Set speed to 9600
If it works you should see/hear controller reboot
Sending :03# should return the firmware version
Sending :00# should return the focuser position
If it works with the serial port monitor it should work with the windows app
Cheers
Robert
Thanks Robert thats great.
I did order an hc05 module on ebay but it appears i have been sent an hc06. It seems that an hc06 is only a slave while an hc05 can either be a master or a slave. As i gather the hc05 has to be set to as a slave. I went ahead with the hc06.
As i say it works in a fashion it does show two com ports but i can only connect it with a usb cable plugged in. If i try to connect via a bluetooth com port they give an error message failing to connect. I don't think i will be spending too much time with this trying to get it to work.
Regards
Charles Clark
Update on the bluetooth module. This is now working fine without really doing anything to it. I fid find that on switching on an external power supply that whilst getting 8 volt on the lm708 diode it didn't appear to be getting to the vin connection of the nano, hence it and the bluetooth module did not power up. When checking with a meter it beeped and powered up and I was able to connect up com7. I guess I may have a dry joint somewhere on this leg.
I will need to sort this out when I box it all up.
After that it will be a question of how reliable it is.
Stepper motor is working great on 1/4 steps by the way but i did include the micro stepping module that was recommended.
Thanks for all your help and guidance.
Regards
Charles Clark
To drive the LM7808 regulator that provides voltage to the nano board will require at least 10VDC input. The circuit is designed to have 12VDC input as external power supply. Less and there will be issues.
This is why recommended power to board is 12VDC, which the LM7808 drops down to an acceptable 8V input to VIN of the nano board, which then drops to 5V to power the nano IC.
Hi Robert I have two focuser controllers both based on the 2017 v11 board. One is a Stripboard build which was working fine I built the second one from a PCB board based on your gerber files. The stepper motor is a NEMA 14 400 step at 0.9 degrees/step and is also geared down via pulleys at 3 to 1. They are set up with the diodes to micro step
The PCB one is working fine but the stripboard version has stopped working for some reason it goes through the motions but the stepper only makes a noise no turning I have tried adjusting the current as per your videos and tried also to alter the delay. Having a light bulb moment I vaguely remember taking the DRV 8825 driver from the stripboard and putting it in the PCB version. Getting some cheap DRV drivers for replacement. I have purchased a Polulo DRV8825 , but while the noise has improved the motor will not turn. The PCB version however runs sweet as a nut. I have completed another PCB board based on the same 2017 v11 schematic but with the micro steeping diodes built into the board, this has a similar problem to the stripboard build.
The Arduino Firmware I have installed in both focuser's is v301 of the DRV8825 H203 firmware and the windows software is v2.4.5.6 Both focusers are using the same stepper motor with the same version of windows. I am loathe to take bits off the one that is working in an attempt to fault find and end up with two that do not work.
Can you advise me what is the difference between a DRV 8825 driver and a DRV8825 H203 version. I have trawled the internet trying to find out but in the UK I can only find DRV 8825 version available.
Also with a 2017 v11 build of focuser running a stepper motor with microstepping based on a DRV8825 driver what version of Arduino firmware and windows software should i be installing.
Many thanks in anticipation
Regard Charles Clark
Can you advise me what is the difference between a DRV 8825 driver and a DRV8825 H203 version.
This refers to the firmware and PCB versions. The DRV8825 is used on both. The difference refers to the design of the PCB and the Firmware
The DRV8825 PCB means what we originally started with - a stripboard. But after a short while I decided to make a PCB design.
In order to make the tracks look neater and avoid the use of via's on the PCB, I changed the MS1 and MS3 lines over for the new design called DRV8825HW203 PCB. The MS1/MS2/MS3 lines control the microstepping.
That is why the DRVHW203 PCB has its own firmware file, because the pins were changed.
If you try to use a DRV8825 PCB with DRV8825HW203 firmware the microstepping is all wrong
If you try to use a DRV8825HW203 PCB with DRV8825 firmware the microstepping is all wrong
DRV8825 PCB = DRV8825 firmware - OK
DRV8825HW203 PCB = DRV8825HW203 firmware - OK
Also with a 2017 v11 build of focuser running a stepper motor with microstepping based on a DRV8825 driver what version of Arduino firmware and windows software should i be installing.
I do not know because the info you gave is not enough.
In general
If D5 of the Arduino Nano is connected to MS1 pin (next to EN) then it is DRV8825 design.
if D5 of the Arduino Nano is connected to MS3 pin then it is DRV8825HW203 design
a DRV8825 design requires firmware myFP2_DRV8825_310
a DRV8825HW203 design requires firmware myFP2_DRV8825HW203_310
The windows app does not care what type of board or design you are using
Trouble shooting the motor - see
https://www.dropbox.com/s/ks3cwabbg2cxcou/Stepper%20Motor%20Issues-01.mp4?dl=0
Cheers
Robert
Hi Robert,
Thanks for explaining the differences between the DRV8825 HW203 build and the DRV8825.
I have checked out the board that is working which is from a PCB board from your Gerber Files and the pins are as follows :
D5 - MS1
D6 - MS2
D7 - MS3 which equates if I understand correctly to a DRV 8825 design however it is working fine with DRVHW203 301 firmware, which has confused me
The stripboard version that was working is as follows:
D5 - MS3
D6 - MS2
D7 - MS1 which would indicate that it is based on a DRV8825 HW203 version
My modified PCB build with the micro stepping diodes on the board is :
D5 - MS1
D6 - MS2
D7 - MS3
This would indicate a DRV8825 design
I therefore downloaded and installed DRV8825 v310 as suggested
This did not work and for some reason I have lost 12volt supply to the board it appears that the Resettable Polymer fuse has blown compounding the issue.
Any advice would be much appreciated in particular with the HW203 firmware working with what checks out to.be a DRV8825 design board
and what could cause a polymer fuse to blow could it be that the voltage was set too high on the DRV8825 driver.
I have removed the DRV8825 from the board to see if the fuse would reset in case there was a short but no joy
Thanks in anticipation
Regards Charles Clark
Any advice would be much appreciated in particular with the HW203 firmware working with what checks out to.be a DRV8825 design board
Yes DRV8825HW203 will run on a DRV8825 designed board - BUT, as I said earlier, the step modes are set incorrectly. Let me explain further
This is how microstepping works
Now assume that you have a drv8825 pcb design and incorrectly load the drv8825hw203 firmware.
When a user selects half step mode the firmware sets MS1 HIGH or Logic 1. (100 from MS1 to MS3).
But the firmware swaps over MS1 with MS3 so in effect it is 001 (from MS3 to MS1) which means selecting 1/4 stepmode results in stepmode 16.
=====================================
My modified PCB build with the micro stepping diodes on the board is :
D5 - MS1
D6 - MS2
D7 - MS3
This would indicate a DRV8825 design
I therefore downloaded and installed DRV8825 v310 as suggested
This did not work and for some reason I have lost 12volt supply to the board it appears that the Resettable Polymer fuse has blown compounding the issue. and what could cause a polymer fuse to blow could it be that the voltage was set too high on the DRV8825 driver.
I have removed the DRV8825 from the board to see if the fuse would reset in case there was a short but no joy
Reprogramming drv8825 board with firmware 310 will not blow the fuse, so there is something else going on.
Before we can get into that you need to ensure that the focuserconfig.h file specifies the correct settings for your board or design. In particular enabling the stepper power detect when the hardware circuit for this is not present on the board.
The Polymer fuse resets itself when power is off. It is quick to blow if there is a power issue and the current exceeds 3A. For this to blow then you have a serious SHORT on the board between power and ground. I would start by a good visual inspection of the board and checking for any shorts near GND and the 5V/12V power pins. Another thing that can cause something like this is incorrectly connecting something the wrong way round, like the I2D display or incorrect wiring of the temperature probe.
The LM7808 circuit that provides power to the board from 12V PSU will tolerate a little higher than 12V but not much.
If you have a multimeter, you can try the troubleshooting in the attached zip file, it shows the points to measure and what is expected.
If you do not have a multimeter let me know and I can put comething together on how to troubleshoot the issues without using a multimeter.
Regards
Robert
Hi Robert,
Many thanks for the Trouble Shooting zip file it is greatly appreciated as well as you clarification on the difference between a DVR8825 and DVR8825 HW203 build.
I have managed to get sorted out with both working with DRV8825 v310 firmware
The one that stopped working and lost 12 volt power was not down to a short but a dodgy header pin ground connection, some how the ground pin had pushed back in the header and was not fully home to the pin on the board.
Sorting this still did not cure it not working but it allowed me to check voltages as described in your trouble shooting file, these were fine.
Checking the 1A, 1B, 2A,2B continuity was giving spurious results so I decided to remove the micro stepping diodes from the Board (I thought I was being clever incorporating them into the main board, big mistake as there was some obvious bad joints because of the solder not taking well to having too many components together taking the heat away from the soldering iron)
Wired this up with no diodes but it still did not work Checked the voltage on the pot on the DRV8825 and there was none, so I had obviously blown it, Replaced it with a cheap one I had and it worked fine.
So Many thanks for your patience and guidance much Appreciated
Regards
Charles Clark