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  1. Yesterday
  2. I'll post a video of the Panda Bear in action. So please come back in a few days.
  3. There's a handful of electronic modules that do all the magic. Here's a photo from an early bench test. The brains behind this talking bear is a ESP32 WiFi enabled microcontroller. It's mounted on a piece of Perfboard with two MOSFET modules (for driving the blower and wand motor). A high current relay is used to provide DC power to the 30W audio amplifier. The 433MHz receiver was originally mounted on the ESP32's perfboard, but EMI/RFI issues reduced the wireless button's range. So the receiver was moved further away. The photo below shows the placement of the ESP32 and receiver. The off-the-shelf Audio Amplifier module uses a TDA7297 power amp IC. It provides two 15 watt channels. ESP32 projects that involve sound playback typically have some sort of audio hardware such as a MP3 module. But to simplify construction the audio generation in this design is software based. All thanks to the ESP32's onboard DAC and the open source XT_DAC_Audio library published by xtronical.com. Here's the full schematic: Schematic.pdf
  4. Let's not forget that the Panda Bear is an important part of the entertainment. It's no secrete that most kids (and adults) like teddy bears. The bear is a custom made aluminum sign about 18" wide by 24" high. Despite its one-dimensional construction, it can talk and has lips that articulate while speaking. Here's a sample of what the bear can say: The child-like voice is from a Gund Peek-A-Boo Teddy Bear. It's a stuffed plush toy that was purchased from Amazon, but other retailers sell it too. I highly recommend this animated toy to all the little people in your family. A pushrod connected hobby servo moves the mouth. Software synchronizes the movements to the voices stored on audio wave files. Here's an inside view that shows the hidden servo: The open mouth was painted red (becomes white when the lips are closed). See photo below: Directly above the bear are a pair of car speakers driven by a 30 watt (2 x 15W) audio amplifier. The audio quality is good with plenty of volume. Between the speakers is a WiFi security camera for safeguarding the installation. Sad to say, but some people are angry at the world and might want to hurt this bubble loving bear. A video recording should help ID those involved in any animal cruelty that may occur.
  5. Let's step back for a moment and talk about bubble production. Normally a person blows into a soap dipped wand while observing the bubble form. Air volume / lip position is adjusted in real-time to create the perfect bubble. A classic closed loop system. My bubble maker runs open loop. Even so, it does a remarkably good job at blowing bubbles. As mentioned, the blower and wand speed are programmable, which helps out a lot. Admittedly, some success is probably a bit of magic and luck. The very first test used a 9V battery to run the blower and a 2.4V NiMH battery for the wand carousel. I set it up outside and let it run for awhile. The results were promising. This ad-hoc testing confirmed that a calibration step would be ideal for optimizing the blown bubbles. At this point the hardware/software to do that had not been built. I also experimented with the bubble solution mixture. There's plenty of recipes published on the interwebs. Typically the magic ingredient is corn syrup or glycerin. So far I'm having good luck with Palmolive dish soap (original formula), food grade gylcerin, and filtered water. I make about a half gallon at a time. After mixing I let it rest overnight to help degass it.
  6. Last week
  7. Making bubbles is a simple task that is just a bit of soap and air. Or so I thought. It turns out that bubble blowing success is affected by several variables: For example, the contour of the wand, air management, and the soap solution's formula all contribute to the bubble maker's performance. There are twelve wands that are arranged in a carousel configuration. It's just a slow rotating wheel. All the parts are 3D printed in ABS plastic. Bright garish colors are ideal for this kind of project. The bubble making mechanism uses a low RPM Gear Motor and a mini Squirrel Cage Blower. They were purchased from a China supplier and delivery took several weeks. Both are 12V rated devices, but run at lower voltages that are configured during "calibration." A custom web app is used to adjust the gear motor and blower speeds. Specifically, PWM (pulse width modulation) control is used to alter their supply voltages. This calibration step is important to ensure good bubble production. Here's a screen shot of the web app. The settings are stored in EEPROM for use as power-up defaults. Yes, this little fellow is smarter than the average bear. There's a float switch in the soap reservoir for monitoring the fluid level. Status is sent by eMail (and MQTT messaging for home automation alerts). Here's an example of an email message that is sent with each playtime interaction. The bubble maker can be removed from the window frame for refilling or cleaning. Just unplug a connector and lift it out from the frame's lower trap door. Here's a rear view, which shows the electrical cable for the blower, wand motor, and float switch: BTW, the reservoir holds an entire day's worth of soap fluid. But as mentioned, if the level gets too low I'm sent an email to refill it. I prefer an email over text, but either notification method is possible.
  8. The bear and bubble maker are built into a 45-inch high wooden frame that's fitted into an upstairs window. There's some 3D printed hardware that holds it in place. Basically a thirty second installation. Down at street level there are two arcade gaming buttons that send a RF signal to trigger the Bear into action. The button on the tray can be pressed with a finger or elbow. A second tethered button is for foot activation (hands-free for health safety). There's a big wooden power pole on our lawn that is a convenient place to install a banner sign and the two buttons. Should the power company discover it I expect a stern lecture about hanging stuff on their ugly utility pole. And if the bear fails to charm them I'm prepared to dig a hole and install my own post. Printed instructions invite the visitor to press a button if they want to play. Although most use the foot button, I've seen many elbow presses too. We thoroughly disinfect the tray area several times a day. The two buttons are wired to a 433MHz Remote Control transmitter purchased from a Chinese supplier. It has a four channel encoder, but only one button channel is used. The circuit board was removed from the plastic FOB case and reinstalled in a 3D printed housing. The original 12V battery was changed to a common 9V type. Range is about 150 feet which is more than enough. The button activated UHF transmitter is mounted inside the tray unit. I discovered that the RF amp stage had good impedance matching to a compact helical antenna I borrowed from another 433MHz project. That is to say, range was better than the factory whip antenna.
  9. Late February 2020, when the COVID-19 pandemic shizz was beginning to hit the fan, I noticed more families spending time outdoors. And slowly my quiet neighborhood began to come to life. Soon hoards of walking/biking moms, dads, and their kids began traveling past my house. This unusual migration of neighbors was a side affect of the lock down. For fun, many nearby homeowners put teddy bears in their windows to entertain these nomadic visitors. It's a game; count the most stuffed bears and you're the winner. Mind you, the windowed teddy bears are not a new thing, but the pandemic seems to have increased their popularity. The teddy bear game seemed brilliant to me. So I joined in on the fun, especially since any entertaining distraction from the pandemic had to be a good thing. I didn't have a stuffed toy bear to display. So a window was decorated with a big paper cutout of a panda bear. Soon families were pointing at it during their walks. Below is a graphic of the two foot tall bear that was printed. By early March 2020 the pandemic worries were escalating and I wanted our bear to add a bit more joy to the world. That's when I decided our teddy would blow bubbles and talk to the visitors. So I'm here to tell the story of my pandemic panda. We call him Bubbles-the-Bear. He is WiFi enabled, has a friendly child-like voice, and makes a lot of bubbles using a homemade soap solution. Stick around, I'll be showing photos of the build and will include some commentary. A YouTube video will go here. Please wait, I'll post it soon.
  10. Earlier
  11. Thanks Thomas for your suggestion.I will try different distance and see which works best.I am going to put everything on one tripod.I have 2 oracle diversity controllers and might try 4 antennae too!!
  12. Thanks for the positive feedback on the Oracle Diversity controller. Many users find that about a wavelength in separation (9-inches) is fine for typical 1280MHz RF spatial diversity. But sometimes 3X wavelength (or larger odd numbered distances) is better. There are a lot of opinions on it, so do some experimentation to find the best distance for your installation. BTW, I'm not an exact antenna placement type of diversity user. I just put one antenna (and its receiver) in a convenient spot, and put another a few feet away, and connect them to the Oracle (or Diversity Demon) controller with some A/V cables. Might not be optimal antenna placement, but my thoughtless method works pretty good for me. - Thomas
  13. Hi all, First of all i would like to thank Thomas for creating a Oracle diversity controller!! I was using eagle eyes and when i tried oracle,its a day and night difference.Oracle is much more faster than eagle eyes.It switches so quick and fast that you don't even notice.Where as eagle eyes takes so much time to switch after the reception on one antenna goes bad.I even tried max sensitivity on eagle eyes but no improvement. Now to my question.I am running two 1280 RHCP antennae and would like to know how far i should separate them for good diversity setup in which i get minimum multi-path static on my video?Thanks.
  14. 1. The Arduino's ADC performance, including accuracy of Vref, is involved too. So even if your power sensor is a perfect match to the one I used, the measurements may be different. The default AD8317 cal values in the Arduino code were determined from my build. The default AD8318 cal values are estimations. In either case, calibration is required if measurement accuracy is important. 2. The sensor detects RF power by measuring RF current. It cannot determine frequency. For budget friendly frequency measurements I suggest a low cost SDR dongle. For example: https://www.rc-cam.com/forum/index.php?/topic/3891-20-spectrum-analyzer-for-testing-fpv-systems/
  15. Does anyone have any info on my other question? (The AD8318 have factory settings and without calibration did anyone take measurement to see how much error there is?) And one last, then I promise I finished: can this be used to perform an automatic frequency search in some way (say with an arduino program modification)? This can be useful if we do not know the exact frequency.
  16. Thanks Thomas.I will double check that metal ridge at the end of the SMA connector.
  17. It's up to you. I didn't add a shield and no issues have been encountered.
  18. Your TBTE6CP26B3 tuner is the same module that is mentioned in the original post of this discussion. The China manufacturer was never identified. It worked OK, but Comtech performance was generally more consistent. Also, some had an undesirable metal ridge at the end of the SMA that often caused poor connection to the antenna and/or coax feedline. A 4.6mm diameter ream can be used to remove the ridge on the SMA connector. Note: Comtech tuners do not need this rework.
  19. Old thread but need some info. I just got hold of old Racewood TR1500 1258MHz receiver.But when i opened it up and found a different module than a comtech? I tested it wit 433MHz dragonlink and its showing no interference even at running dragonlink at full power and placing dagonlink's antenna by the receiver antenna. So wondering what module is it?Is it good quality with good sensitivity for long range?Normally in the past,all the tuners other than comtech showed massive interference from 433 control.Any info please?Thanks.
  20. I want RF power measurement. Without calibration, it makes no sense and I think the webshop verison should also be calibrated if we want to see real values. I don't know if the AD8318 has default settings (factory calibration), but I don't think so. A silly question: does the AD8318 module not need to be covered with metal shield?
  21. Calibration wouldn't be necessary for those users that only do SWR measurements since it is a relative comparison. But beyond that, calibration would be prudent.
  22. Hi! I Think I'll build the device. I don't really trust the 4-button 1-8000MHz RF Meter that can be bought from web stores. If I do build, I can change it at least through the arduino program if I have to. In my opinion, the web store version also needs to be calibrated, although I saw some videos where it seems pretty accurate (maybe just lucky buyer). I guess right? I will probably be able to calibrate mine, but just one question: has anyone done a comparative measurement to see what the error rate is without calibration? (I know this is also affected by the builded tool, cable lengths, resistors, etc.)
  23. They are similar in performance, but with subtle differences. Download the datasheets for the specs. https://www.analog.com/media/en/technical-documentation/data-sheets/AD8317.pdf https://www.analog.com/media/en/technical-documentation/data-sheets/AD8318.pdf
  24. Nice! Thanks for your answer! I will measure the output of some modules using just sub-GHz ISM band. Do you know if AD8317 and AD8318 have the same accuracy/performance measuring sub-GHz ISM bands?
  25. The sensor's voltage output has a slope and intercept that are dependent on the measured frequency. The datasheet has the full details.
  26. Wonderful work! I've read your project, and it is fantastic! I have one question about selecting a specific frequency using AD8317/18 since their output is just a voltage level. After finding this project, I've already ordered an AD8317 to assembly your RF meter for my lab, and some friends are very excited about this gadget.
  27. Causing interference and failing to provide station identification on amateur radio frequencies. All that for the low price of $18,000. https://www.fcc.gov/document/eb-imposes-18000-fine-against-amateur-radio-licensee
  28. Yes, be careful with the hot air. The nearby components may reflow; Then they can move off their pads while you wrestle with the SAW chip. That's exactly what happened to one guy that messed up his SAW chip upgrade.
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