theropod

After testing my code I found a few bugs and have simplified the flow under which the Arduino and drivers work. Below the dashed line is my latest effort. I have included the Accel Library but have not fully implemented them. Much work remains, such as driving the steppers proportionally to joystick movement, but this code drives my motors very well using the 3 options of the joystick switch. ————- // sketch for driving DIY alt-az // ADAPTED BY R. A. Stephenson for hardware specific application //Arduino Nano, Easy Driver X2, salvage bipolar stepper motors // July, 2018 #include <AccelStepper.h> // create instances from Accel Library AccelStepper stepper1(AccelStepper::FULL2WIRE, 2,3); AccelStepper stepper2(AccelStepper::FULL2WIRE, 4,5); //end Aceel Library define steppers // define which Arduino pins do what #define step_pinx 2 // D2 is step signal pin for X axis L/R #define dir_pinx 3 // D3 is direction control pin for X axis L/R #define x_pin A0 // analog input from joystick for X axis L/R #define y_pin A1 // analog input from joystick for Y axis U/D #define joy_switch 6 // joystick switch INPUT PULLUP #define step_piny 5 // D5 is step signal pin for Y axis U/D #define dir_piny 4 // D4 is direction control pin for Y axis U/D int step_speed = 3; // stepper speed higher is slower void setup() { delay(1000); // 1 second delay to allow easy drivers to power up pinMode(joy_switch, INPUT_PULLUP); pinMode(dir_pinx, OUTPUT); pinMode(step_pinx, OUTPUT); pinMode(dir_piny, OUTPUT); pinMode(step_piny, OUTPUT); } void loop() { // Accel not implemented this code if (!digitalRead(joy_switch)){ // if joystick switch is clicked delay(400); // debounce delay switch(step_speed) { // check speed value and change case 1: step_speed=3; // slow break; case 2: step_speed=.1; // fast speed break; case 3: step_speed=1; // medium speed break; } } if(analogRead(x_pin)>712){ //if joystick moved right digitalWrite(dir_pinx, LOW); // move motor right digitalWrite(step_pinx, HIGH); //send step signal X axis delay(step_speed); // delay set by joystick switch case above digitalWrite(step_pinx, LOW); // stop step signal X axis delay(step_speed); // set above //ENDJOYREAD/DRIVE RIGHT } if(analogRead(x_pin)<312){ //if joystick moved left digitalWrite(dir_pinx, HIGH); // move motor left digitalWrite(step_pinx, HIGH); //send step signal X axis delay(step_speed); // delay set by joystick switch case above digitalWrite(step_pinx, LOW); // stop step signal X axis delay(step_speed); // set above //ENDJOYREAD/DRIVE LEFT } if(analogRead(y_pin)>712){ //if joystick moved UP digitalWrite(dir_piny, HIGH); // move motor UP digitalWrite(step_piny, HIGH); //send step signal Y axis delay(step_speed); // delay set by joystick switch case above digitalWrite(step_piny, LOW); // stop step signal Y axis delay(step_speed); // set above //ENDJOYREAD/DRIVE UP } if(analogRead(y_pin)<312){ //if joystick moved DOWN digitalWrite(dir_piny, LOW); // move motor DOWN digitalWrite(step_piny, HIGH); //send step signal Y axis delay(step_speed); // delay set by joystick switch case above digitalWrite(step_piny, LOW); // stop step signal Y axis delay(step_speed); // set above //ENDJOYREAD/DRIVE DOWN } }

I just finished writing the first draft of the Arduino code. This works pretty well with small bipolar test motors (not the ones mounted to my rig). Instead of driving the Motor Speed inputs on the Easy Drivers I used “case” and “break” instances using the joystick switch, which work like a charm. I may just write in more instances with greater differences. This is a combination of sketches from several sources, and the only real originality is my pin assignments. I don’t think I need to use the accel libray as both motors can be driven simultaneously. Below is my quick and dirty code. Feel free to copy and use as you like. I claim no ownership. Edit to add: I left the LED indicator in the setup, but doubt I ever use it, and has no bearing on functionality. It is not included/used in the void loop.

If this method proves to be wobbly in use I am going to find a sloid hunk of aluminum to act as a spacer between the scope and plate. A one inch by two inch by one inch piece should suffice. I could then eliminate the two upper nuts. I doubt this will be needed with this light scope.

The C90 has 2 - 1/4” X 20 threaded holes in the dovetail bar. I threaded two chunks of all thread into those. On my mount the cross bar from the shredder is an 11mm diameter hex rod. I drilled two holes through the bar and mounted a small 1/4” plate, and countersunk the screw heads for a flat surface on this plate. I drilled two 5/16” holes in that plate to accommodate the 1/4” all thread rods, which are about 1.25” long. One is slightly longer, but I don’t think that part is critical. These slightly oversized holes allow for my lack of accuracy in placing the holes perfectly. I don’t own a drill press. I spun a nut onto the all thread rods on the scope side equidistant away from the scope dovetail/base. On the under side of the plate I put split ring lock washers and two more nuts to secure the scope to this plate. Very solid! Attached is a closeup of my solution.

I may add those features, but right now I just want the junkpile to turn and tilt on command. I have been suffering the vulgarity of trying to use a ball head to point the scope, and this has been a study in massive frustration. My ball head is an iOptron I bought via eBay that was apparently a factory reject as it doesn’t want to lock into position no matter how tight I screw down the clamps. The seller wouldn’t honor a return for defect and eBay awarded a full refund. It holds my phone for meteor hunting, but creeps with the scope attached. I have been fighting this a year, and this is my low budget solution. I wasn’t aware of the fair superior solutions to my quest of astronomy when i started out doing this stuff, and have suffered many a long dark hour in a half crazy angry half freaked out state trying to figure out what I was doing wrong. Buying a ball head and expecting it to fit my needs was the result, and getting a defective unit didn’t help. Being retired and on a fixed income has forced me to find a solution. I know some work remains but as I said I think the hard part is behind me. When I get it working as planned, and mounted to my barn door I will have a 3 axis eq. Goto would be great, but I am mainly going to be working solar system objects with this setup. I will post the finished code after testing. I am still very interested in the iOptron CEM25P or Celestron AVX mount and a deep sky scope, but that will require some piggy bank planning. My whole point with this project was to prove to myself that my McGyver skills are not dead. Maybe I can inspire others similarly financially challenged. Lol

Here is some serious DIY stuff on a shoestring buget! This is a semi automated altaz I built from junk, literally. The eat/west axis drive is based on the worm gear set from an 80’s Ford pickup windshield wiper motor that had a locked up motor. I chopped off the motor part with my angle grinder, fit a 3/8” socket to the remaining 11mm shaft with JB Weld and ground a pre-mounted timing belt pulley on a small bipolar stepper motor to loosely fit the drive end of the socket. That is mounted to some diamond plate aluminum. The up/down segment is the guts from an old dead paper shredder. The original motor had burned out, but the mounting bracket fit the bolt pattern to another bipolar stepper I had. To couple the worm gear shaft, I again chopped the motor off and cut the remaing worm gear shaft to length, and then coupled that to the stepper shaft. I used some fairly rigid rubber fuel hose slightly smaller than the stepper shaft, which was slightly smaller than the worm gear shaft. I can detect no slipping with my C90 mounted so it seems to work. If I do get slipping a small hose clamp will be employed. I bought two high quality bearings locally for $15 to cradle the cross bar that actuates the final drive, and JB Welded those to the scrap aluminum plate left over from a barn door tracker I built last summer. I am going to use the Arduino Nano to send signals to two Easy Driver bipolar stepper motors for the two axis of movement. I bought two of those analog joysticks via eBay for $6. I have yet to write the code, but with web references I have a pretty good grip on that issue. I bought the Nano and Easy Driver clones from eBay for under $5 each, and got 6 each for WHEN I blow some up. I plan on using old phone coiled cable from the screw terminals, which are salvaged from an obsolete multi-line phone, to the steppers. This should give me plenty of slack and still carry the signals. A small plastic box will house the drive electronics. I have plans to switch the setup off when not actively pointing to both save power and keep the drivers/motors from building heat. As you can see the steppers and gear train hold my scope in position without power. This was actually the test undertaken for the photo. I plan on using the joystick switch to shift the Easy Drivers from full stepping down to 1/8 stepping, and hope to be able to slew quickly and then accurately center my target(s) with very fine movements. The windshield wiper gear ratio seems to be 58.6 to 1, while the paper shredder seems to be 45 to 1. I plan on powering the setup with a sealed lead/acid 12 volt battery I currently use to drive my barn door tracker. Eventually I plan on mounting this to the barn door (separate Ardunio Nano and Easy Driver) and use the battery for both. Besides writing and testing the code I still need to disassemble the gear drives, clean them well and lube them well with a synthetic grease. I may build a cover for the paper shredder gear train, but that isn’t high on the list. I am jazzed to get this finalized and working, and I am pretty confident the hard part is behind me.

From dusk until about 2 am the skies in north Arkansas, USA were nearly perfect, and the meteors were frequent. I managed to capture a dozen with my iPhone using both my barn door tracker and my iOptron SkyTracker Pro for long exposure shots. One 10 minute frame on the iOptron gave me 5 individual meteors. The radiant was clearly defined! The things that stand out about the Geminids is how much slower they are than the Perseids, and the brilliance. The Perseids seem to have a golden hue whereas the Geminids seem far more white. For a meteor chaser last night was awesome even if the prime hours were wasted with clouds. I must have seen 200 meteors and some fantastic fireballs. One particular beauty to the south dove almost to the horizon and finished with a brilliant blue flash.

Very nice!

Don't get too depressed about it. My thing is meteors, and this August during the Perseids it was cloudy for 13 days straight. This is so not typical for Arkansas, USA it isn't funny. I didn't capture a single one. This Saturday is the peak of the Orinids, and it is going to be cloudy again. Maybe I will just move to the Atacama desert and enjoy clear skies every night, or just accept it is what it is.

It seems this time of year is a limited when it comes to meteors. Our Perseid event was ruined by 12 days and nights of clouds and rain, and for those of us that chase these streaks in the sky it was depressing. Being too stubborn to accept that the best occurrence of the year slipped by I have kept at it. This past Friday night there was a marked uptick in activity with at least 8 per hour. This was more action than I witnessed in the proceeding 2 weeks combined! Naturally most of these were out of the frame of my iPhone camera, but attached is a bright if brief one I did manage to capture. I grabbed three others, but were mere elongated sparks by comparison to this. One I didn't get was a bright red fireball that entered from the west and covered over half the sky, and broke into two pieces before turning to ash. This image is a 20 minute tracked exposures using my iOptron SkyTracker Pro, iPhone 6 plus, NightCap low light app, ISO 1,000, white balance ~3,000 with apature setting of 1/2 (f2.2). The bright star to the left is Altair and the bright star on the top right is Vega. Eastern Stone county, Arkansas, USA approximately 11:00 pm CST.

Not really. I just held the pipe over our gas cooking stove and gradually warmed it until well soft and it just slipped on. I did use the "swelled" end where another pipe is supposed to fit, and wobbled the warmed pipe as it cooled so it didn't "mate" with the scope permanently. After it cooled in place I took it off the scope and cut 4 short slits down the swelled portion about 1" long so it doesn't require much force to install or remove, but there remains plenty of clamping action so as to be quite sturdy. I still need to paint it flat black, but it works very well.

I made a dew shield for my C90 using standard 4" pvc sewer pipe. I heated the end of the pipe and slipped it OVER the plastic apature end. It fits snuggly and requires just enough force to remove so it can't fall off. I epoxied a zip tie in place so my DIY Baader solar filter (mounted on a hunk of 1" insulation foam) wouldn't bottom out. The lens cap fits the pipe perfectly.

My wife and I flew out to Sacramento from Little Rock where my son lives and drove a rental Kia up to the Willamette valley with him, and watched the gobsmacking event. It was never my plan to get stunning hi res photos of the eclipse, but to take in the whole thing, and document doing that. To this end I packed my iOptron SkyTracker Pro, matching iOptron ball head, a long-defective half of a small set of Simmons binoculars, some zip ties and the cheapest octopus type tripod imaginable all affixed to a steel T post. A light and cheap projector that let us see sunspots and the rough edges of the moon. That horrid tripod was bought at a wally world during a lunch break on the drive. My wife and I travel light and none of my real tripods would fit in the overhead. The 2024 path of totality will center my property, and I will be prepared! Our hosts had several people over for a watch party. Among them were quite a few kids. My rigged up system of projecting the image was a big hit as most everyone hated those cardboard/filter glasses. I guessed at my polar alignment using GPS and a compass and the sun tracked quite well throughout the event. The cheap thin paper I used allowed viewing from the back so several folks could look at the same time. I didn't allow kids to look from the back because of the possibility of one of them looking past the paper at the partial sun. A jet plane pulled an amazing hook turn and raced the shadow, and dozens of private planes were out watching the shadow zip along. The interstate was completely bogged down in each direction away from the path of totality, and we avoided this using back roads. A friend rode down from the Seattle area and left immediately afterwards. It took him 13 hours of stop and go to get home, which should be a 3 hour ride. Yeah, he was on a Harley. Since my son was born in the south end of this valley we knew about back roads that allowed us a worry free escape. Having seen several partial eclipses had not prepared me for the suddenness of darkness. We were supposed to have experienced 1:55 seconds of totality, but it felt like 30 seconds, or less. My son captured a great diamond ring with his DSLR. His whole family is coming to our place here in the eastern Ozark mountains of Arkansas for the 2024 eclipse. Crossing my fingers now for clear weather in early April, which can be stormy here.

I'd love to see a cell phone imaging contest. R

I have seen similar flashes, but all the ones I see are in pairs. I think what I am seeing is maneuvering thrusters firing. One for course correction and one to stop the course correction.