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Blue Pill / STM32 Noise Pickup

Martin Bonfiore
 

I ran into an interesting phenomenom while troubleshooting my Blue Pill / STM32 based Onstep system.  The symptom was that intermitently, the Onstep would not boot up on power up as evidenced by behaviors such as the tracking LED not coming up and the connection to the SHC failing. 

Long story short, it turned out to be noise pickup on the wires connecting to Boot/Run six pin header.  A typical non-Onstep Blue Pill application would not have wires extending these pins, rather would have jumpers. 

I built my Onstep inside a fairly tight box which includes a number of noise sources (a 12 to 24 volt switching converter and a 24 to 12 volt switching regulator...to allow 12 volt battery operation).  The wires from the Boot/Run header go to a Run/Program switch.  Repeated experimentation where I unplugged these wires and replaced them with jumpers on the header showed that the wires were the source of the problem. 

I was able to reroute the wires inside the enclosure in a way that has completely eliminated the intermittent problem.  Clearly, all systems are somewhat different in terms of wire routing and I would guess most don't have the noise sources in my design, however I would suggest that when troubleshooting Blue pill designs and wires are used to extend the Run/Program operation, that noise pickup be considered as a source of problems. 


Re: Onstep Goto Accuracy

Khalid Baheyeldin
 

On Tue, Jul 20, 2021 at 03:19 PM, Hemendra Rawat wrote:
After increasing the motors Vref to 0.69V and carefully polar aligning and
balancing the scope, the goto accuracy is dead on
That is excellent news ...


Re: Custom Ethernet and INDI: no persistent channel?

Howard Dutton
 

On Tue, Jul 20, 2021 at 12:17 PM, Jordi Sese wrote:
Is that the Adafruit W5500 library?
https://github.com/adafruit/Ethernet2
Yes, indeed. It is needed (this or an equivalent) just because it has the init function that allows to set the CS pin (the CS pin needs to be changed from the default; if you don't, it puts the Wemos D1 into programming mode when connecting the W5500 to the default pin). 
Ok, I pushed those changes to the SWS experimental branch, look them over/test and let me know...

You should look into GitHub if this continues, makes it easier for all. ;)


Re: Onstep Goto Accuracy

Hemendra Rawat
 

Hi Guys,

Took my 8 inch scope for testing last night with the EQ5 mount. After
increasing the motors Vref to 0.69V and carefully polar aligning and
balancing the scope, the goto accuracy is dead on. All the five DSOs I
tried were within the FOV of my 25mm eyepiece. Thanks for all the
support, now I can explore the night sky in peace :)

-Hemendra

On Fri, Jul 16, 2021 at 11:34 AM Hemendra Rawat via groups.io
<hkr1990=gmail.com@groups.io> wrote:

Hello John,

I didn't fully understand you question about clutch knobs. Can you elaborate on it? I will work on the polar alignment and balancing when I take my scope out this weekend.

-Hemendra


Re: Custom Ethernet and INDI: no persistent channel?

Jordi Sese
 

Is that the Adafruit W5500 library?
https://github.com/adafruit/Ethernet2
Yes, indeed. It is needed (this or an equivalent) just because it has the init function that allows to set the CS pin (the CS pin needs to be changed from the default; if you don't, it puts the Wemos D1 into programming mode when connecting the W5500 to the default pin). 


Re: Focuser for MaxEsp3

Howard Dutton
 
Edited

On Mon, Jul 19, 2021 at 12:26 PM, Seven Jones wrote:
The only problem is that the NEMA17 becomes very hot. I've left the Vref already down to 0.5V.
Well DRV8825's are usually Vref x 2, so you probably set 1A.  There are plenty of stepper motors that are rated for < 1A and will get mighty hot or damaged (given enough voltage into the driver for it to do what you're asking.)  That last part about the voltage is due to the fact that's it's impossible to overpower a stepper motor if operating below the rated (design) voltage.

Provide electrical specifications for the motor, also the voltage you're running it at.


Re: Connect gearbox and confing help #mount #configuration

Robert Benward
 

Wow George, those go way back....Probably older than many of us on this group!


Re: Focuser for MaxEsp3

Seven Jones
 

On Tue, Jul 20, 2021 at 07:17 AM, George Cushing wrote:
Remember that if you use the #define AXIS4_DRIVER_POWER_DOWN       ON option the motor is getting continuous power. 

"#define axis4_driver_power_down" is OFF.

I exchanged the engine against a NEMA17 with 60mm. And so far it works well. Besides that 4 pin 4p4c cables is pretty hot. Href is 0,75V.

I also had the DRV at the beginning of the CNC. But there were always problems with the temperature of the motors or the driver.
Which alternatives do I have the choice of drivers for AXIS 3 and 4?

If I understood correctly, I can also use the 2130 there but do not set the steps via SPI or jumper to any value?

 


Re: Custom Ethernet and INDI: no persistent channel?

Howard Dutton
 

On Tue, Jul 20, 2021 at 10:04 AM, Jordi Sese wrote:
- change ethernet.h to ethernet2.h (with an #ifdef ESP8266) in almost all files in EthernetServers folder
Is that the Adafruit W5500 library?
https://github.com/adafruit/Ethernet2


Re: Help: Failed programming the Blue Pill

Khalid Baheyeldin
 

If the Wemos advertises an access points and allows connections to it, then it is probably working.

The 169 address is something reported occasionally here.
Can't remember if using the specific board manager version that is on the Wiki fixed it or what.


Re: Help: Failed programming the Blue Pill

Yen Quy <quy_yen@...>
 

Yea, I was able to connect to Onstep. But my laptop has a 169 address which is invalid, and I couldn't connect to web server at 192.168.0.1! I wonder if that Wemos has problem because it was exposed to high voltage. So I'll replace it with a new one after work to see.


Re: Custom Ethernet and INDI: no persistent channel?

Jordi Sese
 

Hi Howard,

Thanks for your work. Yes, it compiles, but in EhthernetServers.cpp there was a small typo in ethernetPersistantCommandChannel function, when you read cmdSvr instead of cmdSvrPersistant. After that change, it seems to work. I will tell you more when I test it.

Also, just in case you want to add support for ESP8266 Ethernet, those are the other changes I performed for SWS to make it work with Wemos D1 + W5500:
- change ethernet.h to ethernet2.h (with an #ifdef ESP8266) in almost all files in EthernetServers folder
- change W5500_RESET_PIN to D2 in Pins.ESP8266.h
- add a W5500_CS_PIN definition (and set it to D1) to Pins.ESP8266.h and call Ethernet.init(W5500_CS_PIN) just before your Ethernet.begin() in WebServer.cpp
- modify EthernetServers.h to avoid validation error, adding ESP8266 support

Thanks for your time, and regards.

Jordi.

 


Re: Help: Failed programming the Blue Pill

Khalid Baheyeldin
 

I can't tell you what happens on Windows, because I don't use it.
On Linux, USB drivers are different: they are universal, and builtin. So we don't even notice them.

Regardless, whatever Wemos you are using should be flashed with the Wifi component (or SmartWebServer if you are adventurous). Then when you power on OnStep, the STM32 will blink (because tracking is auto started), then the Wemos will blink for ~ 8 or so seconds, then go solid. At that point you should be able to connect to the ONSTEP access point from a phone.


Re: Help: Failed programming the Blue Pill

Yen Quy <quy_yen@...>
 

Thanks, Khalid.  I did turn on auto tracking in the config.h.
The WIFI module appears to work, I was able to program it and connect to OnStep.  However, when connect to the computer, it only appears as 'USB to Serial' port 10, as apposed to 'USB to Serial CH340'.  I don't know if that matters.  It also doesn't assign an IP to the PC connected to the Onstep WIFI.  The 2nd Wemos I'm preparing shows the correct enumeration in Device Manager with the 'CH340' in its name.  I'll see it I can get a valid IP when I try this new module.


Re: Help: Failed programming the Blue Pill

Khalid Baheyeldin
 

For the WiFi adapter, it is easy to test.
Basically if it blinks for ~ 8-10 seconds then its LED goes solid, then it can connect to OnStep.

For the STM32, output looks good.
Did you turn on auto start tracking in Config.h?
If not, then it should not be blinking.

Using Serial Monitor in the IDE, enter the commands at the end of the this page.
See if you get responses back.


Re: Components list #cge #S6

Khalid Baheyeldin
 

On Tue, Jul 20, 2021 at 12:56 AM, <bolex_2695@...> wrote:
I am wondering what else I need or are this components enough ?
Spend some time on the links in the showcase page.
There should be some mounts like yours.
Look at how they did it, so you can borrow some ideas.


Re: Focuser for MaxEsp3

George Cushing
 

Remember that if you use the #define AXIS4_DRIVER_POWER_DOWN       ON option the motor is getting continuous power. 

I have found that the DVR8825 will run Vixen MT1 drives (PF42-48) hot unless I set them to 0.03A. The PF42s are 6 wire steppers and they have no current rating. So using the DMM and Ohm's Law (Voltage (V)/ Resistance (R) = Current (I)), where V=12 and R=200Ω we find that The PF42s max current is 0.06A and half of that is 0.03A.

Driving the PF42s by half coil (100Ω) doubles the current needed to 0.06A. They still run warm to the touch but not hot.


Re: Connect gearbox and confing help #mount #configuration

George Cushing
 

And of course there's this approach. 



Worm gears from a Celestron fork mount. 

180 tooth Meade 2080 set:



I have about a half a dozen Meade sets.


Re: Components list #cge #S6

Yen Quy <quy_yen@...>
 

I also have the CG4 mount. For this mount, if you want to use any pulley larger than 30 teeth, you'd need to extend the shaft. Even with the 30 teeth, you still need to file the RA lock handle a couple millimeters for the motor to pass.  I'm using 16 teeth on the motor and 48 teeth on the RA/DEC.  Still waiting for the 12 teeth order.
I also bought the JST XH2 wire+connectors.  they are pretty useless because they only have connector on one end so I ended up buying my own crimp tool to make my own wire.


Re: Components list #cge #S6

bolex_2695@...
 

Thanks for your reply, I am wondering what else I need or are this components enough ?

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