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Abandoning Blue/Black Pill. What Next?


Gerry Byrne
 

Hi All,
Just heard from RobotDyn to say they are cancelling my Black Pill order because of "IC defects" and instructing me to claim back my cash. A supplier I tracked down in Bucharest with Black Pill (303) stock is also refunding me saying it cannot ship outside Romania.

I think that draws a firm line under my STM32 project because I cannot get a 303 board. None of the five 103 boards I now have works. I think the rest of my build is good because I did succeed in getting an earlier one flashed, only to burn it in an accidental current overload event.

I want to complete an Onstep installation because I have already equipped my Dob with toothed drives and bearings in addition to investing in two geared stepper motors.

What should I try next? Will I be able to re-use any of the components I have already got or should I just cut my losses and start afresh?

Gerry Byrne

--
Copernicus


Khalid Baheyeldin
 

On Wed, Nov 25, 2020 at 06:13 PM, Gerry Byrne wrote:
Hi All,
Just heard from RobotDyn to say they are cancelling my Black Pill order because of "IC defects" and instructing me to claim back my cash. A supplier I tracked down in Bucharest with Black Pill (303) stock is also refunding me saying it cannot ship outside Romania.

I think that draws a firm line under my STM32 project because I cannot get a 303 board. None of the five 103 boards I now have works.
Are you sure that you checked the R3 resistor on the underside of the board?
What is the marking on it?

I think the rest of my build is good because I did succeed in getting an earlier one flashed, only to burn it in an accidental current overload event.

I want to complete an Onstep installation because I have already equipped my Dob with toothed drives and bearings in addition to investing in two geared stepper motors.

What should I try next? Will I be able to re-use any of the components I have already got or should I just cut my losses and start afresh?


Gerry Byrne
 

Khalid,
The R3 resistor reads 104. (see attached photo).
Gerry


On 26/11/2020 00:24, Khalid Baheyeldin wrote:
On Wed, Nov 25, 2020 at 06:13 PM, Gerry Byrne wrote:
Hi All,
Just heard from RobotDyn to say they are cancelling my Black Pill order because of "IC defects" and instructing me to claim back my cash. A supplier I tracked down in Bucharest with Black Pill (303) stock is also refunding me saying it cannot ship outside Romania.

I think that draws a firm line under my STM32 project because I cannot get a 303 board. None of the five 103 boards I now have works.
Are you sure that you checked the R3 resistor on the underside of the board?
What is the marking on it?

I think the rest of my build is good because I did succeed in getting an earlier one flashed, only to burn it in an accidental current overload event.

I want to complete an Onstep installation because I have already equipped my Dob with toothed drives and bearings in addition to investing in two geared stepper motors.

What should I try next? Will I be able to re-use any of the components I have already got or should I just cut my losses and start afresh?


--
Copernicus


Khalid Baheyeldin
 

On Wed, Nov 25, 2020 at 07:44 PM, Gerry Byrne wrote:
The R3 resistor reads 104. (see attached photo).
That is your problem!

Using a soldering iron, heat the R3 resistor then flick it off, then heat the two pads
that are now bare, and either create a solder bridge, or solder a small piece of wire
across.
Either way, the module will flash that way.

This solution has been on the Wiki for months.

But I did verify when someone gave me modules that would not flash through
serial, but flash over SWD (ST-Link V2). A light bulb went on, and I tried the
above process myself: it works!

Try it out, and let us know ..


Gerry Byrne
 

Khalid,
The R3 resistor I showed earlier is on a spare module and I went to it (rather than the one already plugged into the PCB) to be able to read the numbers. The one that is presently on the PCB is bridged with solder (see photo) although looking at it closely I think perhaps I made a bit of a dog's dinner of it. I think that's the remains of a pad sticking out of the blob. However, I imagine that even a blob of solder dumped over an in situ  resistor will still short it, do you think? Or should it be completely flicked off first? (It is since coated with nail varnish to prevent oxidation.)

As I said I have several more that I can play with.
Gerry


On 26/11/2020 01:06, Khalid Baheyeldin wrote:
On Wed, Nov 25, 2020 at 07:44 PM, Gerry Byrne wrote:
The R3 resistor reads 104. (see attached photo).
That is your problem!

Using a soldering iron, heat the R3 resistor then flick it off, then heat the two pads
that are now bare, and either create a solder bridge, or solder a small piece of wire
across.
Either way, the module will flash that way.

This solution has been on the Wiki for months.

But I did verify when someone gave me modules that would not flash through
serial, but flash over SWD (ST-Link V2). A light bulb went on, and I tried the
above process myself: it works!

Try it out, and let us know ..


--
Copernicus


Mike Ahner
 

On Wed, Nov 25, 2020 at 07:22 PM, Gerry Byrne wrote:
I think that's the remains of a pad sticking out of the blob. However, I imagine that even a blob of solder dumped over an in situ  resistor will still short it, do you think? Or should it be completely flicked off first? (It is since coated with nail varnish to prevent oxidation.)
I remember that you inadvertently lifted a solder pad while trying to remove this resistor before. It's possible that the plated hole (called a via) is damaged and even with a solder blob, it's not making a good connection. So trying again on another board should fix the issue.

-Mike


Khalid Baheyeldin
 

On Wed, Nov 25, 2020 at 08:22 PM, Gerry Byrne wrote:
looking at it closely I think perhaps I made a bit of a dog's dinner of it.
I made more of a dog's dinner with mine, and it still worked.
See for yourself ...



I think that's the remains of a pad sticking out of the blob.
Looks like the resistor itself wedged into the solder. This is harmless, since it is not touching
any other conducting element.

However, I imagine that even a blob of solder dumped over an in situ  resistor will still short it, do you think? Or should it be completely flicked off first? (It is since coated with nail varnish to prevent oxidation.)
Keeping the resistor in situ should still work, as long as the solder blob has good contact with either sides of the resistor, or the solder on the pads.

As I said I have several more that I can play with.
Yeah, try another module. Maybe a piece of copper wire and soldering each end to the end of the resistor.

Another method is to use an STLink V2 adapter to flash OnStep using the SWD pins, and changing the STM32CubeProgrammer options accordingly ...

You can get such an adapter cheap
https://www.aliexpress.com/item/32719963657.html

But the downside is that you have to take the Blue Pill module out of the PCB every time you want to flash it


George Cushing
 

Just bridging the resistor with solder means you have to apply the parallel resistor rule.

Voltage is the same across each component of the parallel circuit. The sum of the currents through each path is equal to the total current that flows from the source. You can find total resistance in a Parallel circuit with the following formula: 1/Rt = 1/R1 + 1/R2.  
1/Rt = 1/0.02 + 1/10,000 0.0001
1/Rt = 0.02 Ω

So there's really no reason to flick the resistor out of the way just smother it in solder. If you have already mucked up the PCB, or want to play it safe. Solder a resistor (R*) between pin PA12 and 3.3V. If R10 is gone you want something within 50% of 1.5KΩ. Anything between 2.25K and 750Ω will work. 
With R10 in place R* can be found with the Resistor Calculator.
Using a 1.8KΩ nets us 1525Ω. certainly close enough.


image.png

Virus-free. www.avg.com


Gerry Byrne
 

People have been extremely kind with suggestions, and even generous offers of parts, but I have still decided, after spending a whole year getting nowhere, to abandon my Blue/Black pill efforts. (Well, perhaps not a whole year wasted. I did get the Dobsonian mount geared up and added smooth bearings, to the extent that I'm ready to install the steppers).

Here's why no more Blue/Black pill.

At this stage I have gone through six Blue Pill boards with only one (apparent) success in flashing and that ended in smoke due to carelessness. But I have no guarantee that the three Blue Pill boards I have left are flashable, despite shorting R3. I delayed a decision on the promise of salvation from the Black Pill but they have proved almost unobtainable due to quality control issues. I did manage to track some down in Bucharest but the seller refused to ship outside Romania. After burning the STM32 I had replaced the Eeprom and the CP2102  on the assumption they too might be damaged. In the process of removing the old CP2102 I clumsily damaged several vias on the PCB with a soldering iron which was too hot (since invested in a nicer one with a working thermostat control). I had earlier also damaged the PCB when replacing a power control unit which had a dud POT. My workarounds were ingenious (see photos) but still may be flawed. Rather than risk further disappointment and potentially having perfectly good parts malfunction, I have decided to carefully pack my efforts away and re-use some of the parts (LV drivers, Wemos)
on a FYSETC F6 board which will hopefully arrive in a few weeks.

I chose the FYSETC F6 after realising that it was already hardwired to do many of the things controlling an alt/az mount requires. Perhaps there's an element of overkill (I will never need six steppers!) but looking at a friend's 3d printer operate made me realise it does all the things an alt/az telescope mount needs. Move up/down, move left/right. Pretty much straight out of the box. Just add a few parts and software.

I have been rather frustrated with the Blue Pill but don't altogether regret my efforts. In my 73 years I have built sailing dinghies, rebuilt car engines and won science journalism awards but I never before soldered two things together, or properly understood how electronic things worked. I like to think now I am a wiser, not sadder, man.

Will keep you posted on the FYSETC project and will be eternally grateful for any advice you guys choose to throw my way.

Gerry



On 28/11/2020 16:31, George Cushing wrote:
Just bridging the resistor with solder means you have to apply the parallel resistor rule.

Voltage is the same across each component of the parallel circuit. The sum of the currents through each path is equal to the total current that flows from the source. You can find total resistance in a Parallel circuit with the following formula: 1/Rt = 1/R1 + 1/R2.  
1/Rt = 1/0.02 + 1/10,000 0.0001
1/Rt = 0.02 Ω

So there's really no reason to flick the resistor out of the way just smother it in solder. If you have already mucked up the PCB, or want to play it safe. Solder a resistor (R*) between pin PA12 and 3.3V. If R10 is gone you want something within 50% of 1.5KΩ. Anything between 2.25K and 750Ω will work. 
With R10 in place R* can be found with the Resistor Calculator.
Using a 1.8KΩ nets us 1525Ω. certainly close enough.


image.png

Virus-free. www.avg.com


--
Copernicus


Khalid Baheyeldin
 

On Mon, Nov 30, 2020 at 09:48 AM, Gerry Byrne wrote:
Here's why no more Blue/Black pill.

At this stage I have gone through six Blue Pill boards with only one (apparent) success in flashing and that ended in smoke due to carelessness. But I have no guarantee that the three Blue Pill boards I have left are flashable, despite shorting R3.
Did you try flashing them and they failed to flash? If not, then why not try flashing them?
Do you have an ST-Link V2 adapter? If you do, they that will let you flash the Blue Pill regardless of R3.
You just have to do the flashing while the Blue Pill is outside the PCB.

In the process of removing the old CP2102 I clumsily damaged several vias on the PCB with a soldering iron which was too hot (since invested in a nicer one with a working thermostat control).
So user error. Happens sometimes.
But even if you don't have a CP2102, you can still flash the Blue Pill using an ST-Link V2.
Then you can continue to use the controller over WiFi, or through an SHC connected to the ST4.
Since you using the controller for a Dobsonian, the USB port is less important.

I have decided to carefully pack my efforts away and re-use some of the parts (LV drivers, Wemos) on a FYSETC F6 board which will hopefully arrive in a few weeks.
It is the S6 not the F6. I hope you did not order the wrong board, starting on the wrong foot all over again.

I chose the FYSETC F6 after realising that it was already hardwired to do many of the things controlling an alt/az mount requires. Perhaps there's an element of overkill (I will never need six steppers!) but looking at a friend's 3d printer operate made me realise it does all the things an alt/az telescope mount needs. Move up/down, move left/right. Pretty much straight out of the box. Just add a few parts and software.

There are still things that you have to wire: the WeMos connection, and an ST4 with a resistor network if you want an SHC.
These are harder to do when you don't have a PCB that wires all that for you, and just says : "solder here".

So, be careful ... since there are more decisions to be made ...

I have been rather frustrated with the Blue Pill but don't altogether regret my efforts. In my 73 years I have built sailing dinghies, rebuilt car engines and won science journalism awards but I never before soldered two things together, or properly understood how electronic things worked. I like to think now I am a wiser, not sadder, man.

I was like that 3 years ago: no soldering experience, and no electronics experience either.
But watching Youtube videos, lots of reading, and help from friends made both the Blue Pill and S6 possible ...

My advice: If you have a friend who is electronics savvy, then please enlist their help before soldering anything. Better yet, leave them to do the soldering.


Gerry Byrne
 

Khalid,
Homer nods, it was indeed the S6 I ordered.

I had thought about getting an ST-Link adapter but I'm sort of losing faith in the board and at this stage I am not motivated enough to carry on trying. I'm not casting aspersions on anyone's efforts, onstep is a wonderful development but I have, perhaps unluckily, had a few disappointments. First the power unit was a dud and I had to replace it. Then came the repeated failures to flash the Blue Pill and then, when I thought I had finally succeeded, I burned it. That was the third or fourth Blue Pill that had passed through my possibly inept hands. This was followed by the growing realisation that the modern Blue Pill wasn't everything it was supposed to be. The R3 issue was quickly followed by the emergence of boards with limited memory and finally, the rapid disappearance of the Messianic Black Pill from the market due to technical problems.

I appreciate there are still things to be done on the S6 but, assuming the techniques don't overwhelm me, I imagine I shall be less fatalistic about the technology.

Once again I must thank you and your colleagues for your advice, encouragement, and your patience. I may indeed take your advice about the soldering!

I hope I don't become too much of a nuisance in Phase 2!
Gerry



 



On 30/11/2020 21:11, Khalid Baheyeldin wrote:
On Mon, Nov 30, 2020 at 09:48 AM, Gerry Byrne wrote:
Here's why no more Blue/Black pill.

At this stage I have gone through six Blue Pill boards with only one (apparent) success in flashing and that ended in smoke due to carelessness. But I have no guarantee that the three Blue Pill boards I have left are flashable, despite shorting R3.
Did you try flashing them and they failed to flash? If not, then why not try flashing them?
Do you have an ST-Link V2 adapter? If you do, they that will let you flash the Blue Pill regardless of R3.
You just have to do the flashing while the Blue Pill is outside the PCB.

In the process of removing the old CP2102 I clumsily damaged several vias on the PCB with a soldering iron which was too hot (since invested in a nicer one with a working thermostat control).
So user error. Happens sometimes.
But even if you don't have a CP2102, you can still flash the Blue Pill using an ST-Link V2.
Then you can continue to use the controller over WiFi, or through an SHC connected to the ST4.
Since you using the controller for a Dobsonian, the USB port is less important.

I have decided to carefully pack my efforts away and re-use some of the parts (LV drivers, Wemos) on a FYSETC F6 board which will hopefully arrive in a few weeks.
It is the S6 not the F6. I hope you did not order the wrong board, starting on the wrong foot all over again.

I chose the FYSETC F6 after realising that it was already hardwired to do many of the things controlling an alt/az mount requires. Perhaps there's an element of overkill (I will never need six steppers!) but looking at a friend's 3d printer operate made me realise it does all the things an alt/az telescope mount needs. Move up/down, move left/right. Pretty much straight out of the box. Just add a few parts and software.

There are still things that you have to wire: the WeMos connection, and an ST4 with a resistor network if you want an SHC.
These are harder to do when you don't have a PCB that wires all that for you, and just says : "solder here".

So, be careful ... since there are more decisions to be made ...

I have been rather frustrated with the Blue Pill but don't altogether regret my efforts. In my 73 years I have built sailing dinghies, rebuilt car engines and won science journalism awards but I never before soldered two things together, or properly understood how electronic things worked. I like to think now I am a wiser, not sadder, man.

I was like that 3 years ago: no soldering experience, and no electronics experience either.
But watching Youtube videos, lots of reading, and help from friends made both the Blue Pill and S6 possible ...

My advice: If you have a friend who is electronics savvy, then please enlist their help before soldering anything. Better yet, leave them to do the soldering.


--
Copernicus