Gina's DIY All Sky Cam - Complete Redesign

[Gina]

Well it started off flat but I bent it   Actually the film is stiff enough to hold up on its own and it's very much lighter than kitchen foil.  The meter movement only moves much when the assembly is tilted 45 degrees or more.

BTW I don't think I'll be ready for testing tonight, unfortuantely.  All this stuff takes a lot longer than you think!

[JamesF]

I'm working on the focusing issues, Gina

http://stargazerslounge.com/topic/240452-oacapture-040-release/page-2#entry2624335

James

[Gina]

Great   Looks very interesting James

Talking of focussing, by shear coincidence I have just taken a photo of my latest ASC focussing mechanism using stepper motor.

[JamesF]

If you need even finer control you could perhaps use a worm rather than a pinion, though it might be a tricky thing to produce in the 3d printer.

James

[Gina]

Yes I thought about that but the stepper motor has 4096 steps per revolution and I'm using a 12:68 (just under 6:1) reduction gear ratio to the focus lever, so I think the resolution will be fine enough.  5802 steps cover the full focuser range.  I could reduce the motor pinion size and hence number of teeth perhaps if I need more resolution.

[Gina]

Here's a couple of photos of the light tight box.  The odd shaped lump on the side takes the shutter meter movement.  Please excuse lack of depth of focus...

[Gina]

I take it the qhy5 mk 1 is not supported by EZPlanetary. Shame, it's got enough control of gain and exposure duration to give you daylight images without nd film.

Just another thought Gina, in an attempt to reduce the effect of temperature induced focus shift, would it be worth considering painting, or covering the lens body with white? A black lens body under perspex must get REALLY hot.

Huw

Sorry Huw, I missed this post earlier

I haven't tried EZPlanetary but I think the minimum exposure for the QHY5 is 1ms which for other software is far too much but maybe the gain is too much - I don't know at which point in the chain the saturation occurs.

As for temperature variations, I've thought of controlling the heater power to maintain constant temperature within the dome.  With an Arduino already on board it only needs the addition of a DS18B20 digital thermometer and a MOSFET to control the power to the dew heater resistor.

As for painting the lens or whatever, a lot of the lens would be shielded from direct sunlight by the black plastic casing which comes almost to the top of the lens.

[Gina]

Here is the circuit diagram with Arduino control for focus and taking darks.

And with components added for temperature control.

[Gina]

Been tittivating the solar film shutter and meter pointer and I think I've got it better

Power off - shutter closed.

13.5v supply from bench PSU - shutter open.

[Cath]

Yes, that's true but beginning to get complicated.

It can can't it. .. not that we always have the choice for it not too

[Gina]

I seem to have a bit of a problem   I though I had oodles of ULN2003A chips both loose and as part of a stepper driver module.  I used to come across the driver modules every time I looked for something else - now I can't find any   All this searching is taking time and energy.  Maybe I'll pinch one from my 3 scope triple imaging rig and then order a replacement.  I won't be wanting that rig until the autumn I don't think.  Recently the night sky transparency just hasn't been good enough for DSO imaging - it's typical summer haze - not that it's summer but it is pretty warm

[Gina]

Now connecting up the Arduino Nano to a driver module ready for testing.  The Arduino sketch for focussing is already written - it's the one I use for the MN190 scope.  I'll add a bit to it to cater for darks.

// Gina's single remote focussing system using PC control - 2015-02-21 2000.// File name - astro_focuser_half_step_single_01//// Stepper motors used are 28BYJ-48 with ULN2003A drivers// 4 phase, 8-beat motor, geared down by a factor of 64. // Step angle is 5.625/64 degrees.//////////////////////////////////////////////////declare variables for the motor pinsint motorPin1 = 2;	// Brown to driver   - Blue   - 28BYJ48 pin 1int motorPin2 = 3;	// Red to driver     - Pink   - 28BYJ48 pin 2int motorPin3 = 4;	// Orange to driver  - Yellow - 28BYJ48 pin 3int motorPin4 = 5;	// Yellow to driver  - Orange - 28BYJ48 pin 4                        // Green to driver Gnd                         // Blue to driver 12v - Red   - 28BYJ48 pin 5 (VCC)////////////////////////////int incomingByte = 0;   // for incoming serial dataint FocusSpeed = 1;int motorSpeed = 1200;  //variable to set stepper speedint lookup[8] = {B01000, B01100, B00100, B00110, B00010, B00011, B00001, B01001};//////////////////////////////////int focusCount = 0;  // int stepSize = 5;  // how many motor steps correspond to one focussing step - this may need changing after testing//////////////////////////////////////////////////////////////////////////////void setup() {  //declare the motor pins as outputs  pinMode(motorPin1, OUTPUT);  pinMode(motorPin2, OUTPUT);  pinMode(motorPin3, OUTPUT);  pinMode(motorPin4, OUTPUT);  Serial.begin(9600);}////////////////////////////////////////////////////////////////////////////////set pins to ULN2003 high in sequence from 1 to 4//delay "motorSpeed" between each pin setting (to determine speed)void moveBackward(){  for (int s = 0; s < stepSize; s++) {    for(int i = 0; i < 8; i++)    {      setOutput(i);      delayMicroseconds(motorSpeed);    }  }  focusCount--;//  sendFocusCount ();}///////////////////////////void moveForward(){  for (int s = 0; s < stepSize; s++) {    for(int i = 7; i >= 0; i--)    {      setOutput(i);      delayMicroseconds(motorSpeed);    }  }  focusCount++;//  sendFocusCount ();}////////////////////////void setOutput(int out){      digitalWrite(motorPin1, bitRead(lookup[out], 0));      digitalWrite(motorPin2, bitRead(lookup[out], 1));      digitalWrite(motorPin3, bitRead(lookup[out], 2));      digitalWrite(motorPin4, bitRead(lookup[out], 3));}///////////////////////void moveManyF(int count) {    for (int i = (count -1); i >= 0; i--) { moveForward(); }  sendFocusCount ();}   //void moveManyB(int count) {    for (int i = (count -1); i >= 0; i--) { moveBackward(); }  sendFocusCount ();}   ///////////////////////void sendFocusCount (){  Serial.println(focusCount);}/////////Single focuser control ASCII codes :-53 - Single Step54 - 10 Steps55 - 100 Steps56 - Down57 - Up//void loop() {  if (Serial.available())  {  incomingByte = Serial.read();  switch (incomingByte) {    case 53: //     Serial.println("Single Step Focussing");      FocusSpeed = 1;      break;    case 54: //     Serial.println("10 Step Focussing");      FocusSpeed = 10;            break;    case 55://      Serial.println("100 Step Focussing");      FocusSpeed = 100;      break;    case 56://      Serial.print("< ");      moveManyB(FocusSpeed);      break;    case 57://      Serial.print("> ");      moveManyF(FocusSpeed);      break;    default:       // if nothing else matches, do the default        // default is optional      Serial.print("Unrecognised Command: ");      Serial.println(incomingByte, DEC); }  }}

[Gina]

Apologise - there's an error in the sketch above - I added comments without adding comment identifiers.

This one works.

// Gina's single remote focussing system using PC control - 2015-04-15 1500.// File name - astro_focuser_half_step_single_02//// Stepper motors used are 28BYJ-48 with ULN2003A drivers// 4 phase, 8-beat motor, geared down by a factor of 64. // Step angle is 5.625/64 degrees.//int incomingByte = 0;   // for incoming serial dataint FocusSpeed = 1;     // Number of focus steps for up/down buttonsint motorSpeed = 1200;  // variable to set stepper speed - actual rotation speedint lookup[8] = {B01000, B01100, B00100, B00110, B00010, B00011, B00001, B01001};//int focusCount = 0;  // Running count of focus stepsint stepSize = 5;    // how many motor steps correspond to one focussing step - this may need changing after testing//// declare variables for the motor pinsint motorPin1 = 2;	// Brown to driver   - Blue   - 28BYJ48 pin 1int motorPin2 = 3;	// Red to driver     - Pink   - 28BYJ48 pin 2int motorPin3 = 4;	// Orange to driver  - Yellow - 28BYJ48 pin 3int motorPin4 = 5;	// Yellow to driver  - Orange - 28BYJ48 pin 4                        // Green to driver Gnd                         // Blue to driver 12v - Red   - 28BYJ48 pin 5 (VCC)//////////////////////////////////////////////////////////////////////////////////////////////////////////void setup() {  //declare the motor pins as outputs  pinMode(motorPin1, OUTPUT);  pinMode(motorPin2, OUTPUT);  pinMode(motorPin3, OUTPUT);  pinMode(motorPin4, OUTPUT);  Serial.begin(9600);}////////////////////////////////////////////////////////////////////////////////set pins to ULN2003 high in sequence from 1 to 4//delay "motorSpeed" between each pin setting (to determine speed)void moveBackward(){  for (int s = 0; s < stepSize; s++) {    for(int i = 0; i < 8; i++)    {      setOutput(i);      delayMicroseconds(motorSpeed);    }  }  focusCount--;//  sendFocusCount ();}///////////////////////////void moveForward(){  for (int s = 0; s < stepSize; s++) {    for(int i = 7; i >= 0; i--)    {      setOutput(i);      delayMicroseconds(motorSpeed);    }  }  focusCount++;//  sendFocusCount ();}////////////////////////void setOutput(int out){      digitalWrite(motorPin1, bitRead(lookup[out], 0));      digitalWrite(motorPin2, bitRead(lookup[out], 1));      digitalWrite(motorPin3, bitRead(lookup[out], 2));      digitalWrite(motorPin4, bitRead(lookup[out], 3));}///////////////////////void moveManyF(int count) {    for (int i = (count -1); i >= 0; i--) { moveForward(); }  sendFocusCount ();}   //void moveManyB(int count) {    for (int i = (count -1); i >= 0; i--) { moveBackward(); }  sendFocusCount ();}   ///////////////////////void sendFocusCount (){  Serial.println(focusCount);}///////////Single focuser control ASCII codes :-//53 - Single Step//54 - 10 Steps//55 - 100 Steps//56 - Down//57 - Up//void loop() {  if (Serial.available())  {  incomingByte = Serial.read();  switch (incomingByte) {    case 53: //     Serial.println("Single Step Focussing");      FocusSpeed = 1;      break;    case 54: //     Serial.println("10 Step Focussing");      FocusSpeed = 10;            break;    case 55://      Serial.println("100 Step Focussing");      FocusSpeed = 100;      break;    case 56://      Serial.print("< ");      moveManyB(FocusSpeed);      break;    case 57://      Serial.print("> ");      moveManyF(FocusSpeed);      break;    default:       // if nothing else matches, do the default        // default is optional      Serial.print("Unrecognised Command: ");      Serial.println(incomingByte, DEC); }  }}

[Gina]

I have the remote focussing system working but the mechanism doesn't seem free enough - the stepper is struggling to turn the focussing cage.  It does turn it but sometimes doesn't move it all the way it should.  Investigation needed...

[Gina]

Fixed that - focussing now working perfectly AFAICT   Now trying to persuade my Asus laptop to work with both the focuser and camera working at the same time   Using 4 port USB2 hub.  Waiting for the laptop to reboot ATM.

Amazing how everything seems to take ages   I'm using Windows ATM but really looking forward to getting at least this imaging system working under Linux.  It seems so much faster!

[Gina]

I now have two laptops running the ASC   I couldn't get the Win 7 Asus machine to connect to the QHY5 through the USB hub - the fosussing app was fine.  So I've connected the Dell laptop running Linux Mint to the QHY5 and it's working.  I can now focus the lens with the Asus and watch the image on the Dell

ATM I haven't got the shutter control connected and the solar film is over the sensor.  To test the focussing now it's dark, I have put my magnifier ring light above the camera I can see it and focus the image.  The focus control seems fine   No light seems to be getting round the film as the image is clear and free of any sign of stray light.  So I think this system should be fine for daytime imaging

[Gina]

Now have the shutter connected and it's working fine   Only problem now is that I can't seem to get TeamViewer to connect to the Dell.  The wireless LAN is working fine and I can connect from Dell laptop to router and thence to the web.  It's just TeamViewer that's playing up.  I had it working a couple of days ago when it was just a couple of feet from the router (if that makes any difference and I don't see why if the wi-fi is working).

[Gina]

It's essential that I get the Dell working with TeamViewer in the warm room if I'm going to use this laptop.  Anyone have any ideas for solving this?  Please

Meantime, as I sort out how I shall fit the extra bits into the box, I'm looking at incorporating a USB hub within the case so that I only need to run one USB cable.  I have a 4 port USB hub with connectors on cables rather than built in, that has a small PCB with the hub chip on it - photo below.  I think this was the sort of hub PCB I used in the Philips webcam LX mod.  I will have to check that it works with the QHY5 and Arduino Nano, of course.

I would like to remove the full size USB B connector from the QHY5 and connect directly to the PCB but a little reluctant in case I destroy the QHY5.  The USB B connector currently needs a big hole in the bottom of the box to accept the large USB B cable connector.  This is awkward to seal and I would like to reduce the number of connectors to the minimum.

I have been looking into using Python to control the Arduino and it looks like it will be much easier than using VB in Windows   The aim is to use one laptop running Linux Mint to control all the ASC functions.

[Horwig]

I would like to remove the full size USB B connector from the QHY5 and connect directly to the PCB but a little reluctant in case I destroy the QHY5.

Yes, this is what eventually led to the demise of my camera, the usb socket is really hard to remove, I ended up cutting it up, and removing the pins one at a time from the pcb. The tracks from the data pins are VERY thin, I managed to break one, but it worked with a jumper soldered across the break.

Huw

[JamesF]

Yes, this is what eventually led to the demise of my camera, the usb socket is really hard to remove, I ended up cutting it up, and removing the pins one at a time from the pcb. The tracks from the data pins are VERY thin, I managed to break one, but it worked with a jumper soldered across the break.

Huw

Ooooh, does that mean your QHY5 is working again now?

James

[Horwig]

Nope, it is like the proverbial parrot. When I originally removed the usb, I move on to other projects, and left it in the cupboard for months and forgot about it, with no cable attached, when I got back to it I'd forgotten which data pin was which, reckon it didn't like being connected back to front, but don't see why just miss connecting the data would annoy it.

H

[Gina]

Oh dear - I was afraid of that   I guess if PC and camera were both trying to drive each other the chip could have blown.  I presume you took care of static electricity.  I think I might be able to avoid wrong connection with great care   No guarantee though - I often get things wrong

[Cath]

No guarantee though - I often get things wrong

Anyone and everyone will do so from time to time Gina, whether they be a hobbyist or the best money can buy designer, it's normal and necessary, so don't worry bout it !

[Gina]

Arduino and driver module attached to inside bottom of box.  I'm still using the 6 way cable - well it's already glued in and cut to a suitable length so I've just commoned up red, white and yellow for the 13.8v supply and black, green and blue as 0v/ground/earth. 

I'll stick with the standard type B connectors on the QHY5 for now and run two USB cables.  I haven't wired up the shutter override for darks as yet.  Nor the temperature regulation, but I want to have it ready for testing outdoors ASAP.

[Gina]

Testing again.  oacapture on Dell laptop and Linux Mint and focus control on Asus with Win 7.

What's with this grid the James?  Do you know?