Open Panzer
Open Panzer Help & Info => Open Panzer Help => Topic started by: pandknz on September 20, 2018, 07:10:18 PM
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Hi all
Just going to document my three boards that I will assemble for my Stug build.
I have a TCB from Hobby King so that I can use it as a benchmark to test the Scout and Sound boards but I will build my own TCB just because I want to, the cost of components is about the same as the HK one to buy but the three boards will all be RED and build by myself which is the main reason for doing it.
Three boards are here along with all the components from DigiKey, just need a few odd bits like the heatsinks to finish them.
Will post progress report as I go and ask for help if I get stuck.
(http://i206.photobucket.com/albums/bb21/pandknz/IMG_0681_zpsdsv110zx.jpg)
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They look good in red too! I designed the whole website around the shade of purple used by OSH Park, but in the end Hobby King sells them in a crummy hue that is half pink.
Good luck with the assembly, I'll be following your progress.
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Hi all
ok here is todays effort, my first time reflowing and using a hot air station (although I did do a few of those practice boards before my First scout attempt and they all worked ok but they are not as complicated as this beast
Stencil set up
(http://i206.photobucket.com/albums/bb21/pandknz/15a94d0c-2d9a-4ff7-b0cf-d43383c46bcc_zpsqqmzhrlv.jpg)
Paste applied
(http://i206.photobucket.com/albums/bb21/pandknz/IMG_0684_zpsinezcwra.jpg)
Final result
(http://i206.photobucket.com/albums/bb21/pandknz/ea85b7ea-5b65-4fad-9d8d-2093ec5c6e67_zpsklt8ycx7.jpg)
Not tested yet and I still need to have a closer look at all the joints/pads, I have left out the RC pins as I don't think I will need them as I'm connecting direct to the TCB.
Looks good in Red though :)
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From the photos that looks like a very good job and I expect you will find the board to be electrically sound.
Of the three designs the TCB is the most difficult to assemble due to the extremely small pitch of the processor. On the Scout the pin spacing on the processor is much wider and even if you do have some bridged pins they are simple enough to correct afterwards by hand with an iron and some flux.
The one possible pitfall to avoid when assembling the Scout is not to have too much paste on the large heat-pads of the motor driver ICs. If during reflow those short, it will not be good because of course afterwards you can no longer visually examine the underside of those chips, if they are shorted they will fry the chips, the chips are very difficult to remove without damaging the rest of the board, and they are the most expensive components. But from your photos I think you will be fine. You'll notice I also sized the stencil to be smaller than necessary on those heat-pads precisely to help avoid getting too much paste there.
If I had to be extremely nit-picky I might recommend taking one more pass with the scraper to try to get the thickness of the paste down as thin as possible, from what is shown in your second photograph. But again I think you will be fine. Most times the paste is very forgiving and during reflow will clean itself up where previously it looked a mess. However the less paste to begin with, the better.
You are correct, if you won't be using the RC functions you can leave those pins off.
Hopefully you are familiar with flashing the bootloader which must be done before anything else, afterwards you can upload firmware using OP Config as normal. There are various instructions available on the internet and it may also have been discussed already on this forum but if you have questions let me know.
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Another thing that can make your life much easier, are pre-crimped JST PH cables, such as these 6" from Digi-Key: 455-3082-ND (https://www.digikey.com/product-detail/en/jst-sales-america-inc/ASPHSPH24K152/455-3082-ND/6009458)
Combine with the easy-to-source 3-pin JST PH plug housings (you can find them on eBay and all over the internet), and you can quickly create the three-pin data cable that goes from the TCB to the Scout or Sound Card. Here they are at DigiKey for reference: 455-1126-ND (https://www.digikey.com/product-detail/en/jst-sales-america-inc/PHR-3/455-1126-ND/527357)
The larger JST XH cables that are used to provide power to these boards are much easier to find pre-made online and they are also large enough it is usually not a problem to crimp them by hand. But crimping the tiny PH connectors successfully is a near impossibility unless you have the exact right crimping tool.
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Thanks for all the help Luke
Have you ever tried using an Arduino to program the bootloader/ I have one handy but if not I will just buy one
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Great job on the PCB's! You beat me to it ;D
How did you fare with the positioning of the SMD components? The LED's are the only one that have specific +- orientation or not?
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Hi
Using my microscope goggles its not bad, at 10X I can actually see ;)
There are a couple other components that are polarity sensitive also like the Zener diode and its hard to see the line on the cathode side, I think I got mine right :o
Next is to try and bootload it this will tell me if all is well :)
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Have you ever tried using an Arduino to program the bootloader?
I personally have not tried that but there are tutorials online. A USBASP is only a couple dollars and would be less hassle. Another thing that makes life so much easier is an ISP pogo-pin adapter like this one from SparkFun (https://www.sparkfun.com/products/11591).
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all good, just thought I would ask, I have ordered:
4x 2.0 mm 3 PIN PH JST Micro Connector - This will make two data cables
1x Basic Breakout Board For FTDI FT232RL USB to TTL Serial IC Adaptor 3.3V 5V FT232
1x 10 Pin Convert to 6 Pin Adapter Board For ATMEL AVRISP USBASP
1x 5V USB ISP USBASP Programmer Downloader Cable for Atmel AVR ATMega
This should be a good kit to do all my programming/firmware updates
Now back to the model while I wait for these to arrive
:)
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You should be good to go with all that!
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Ok, still waiting to get the cables for the USBasp to programme the Scout so moved on to the sound card
(http://i206.photobucket.com/albums/bb21/pandknz/IMG_0691_zpsz39tqoq9.jpg)
(http://i206.photobucket.com/albums/bb21/pandknz/IMG_0690_zpscbakv9mq.jpg)
Now to do a bit of firmware and file uploads for sound and I will test it, hope it runs as well as it looks :)
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Very Nice! Keep us posted about the programming!
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You've done some good assembly work I can tell!
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Thanks guys
so I have no sound....
I have not got my serial cables yet but when hooked up with the TCB it has a slow flashing red led so this is normal waiting for a signal which I cant provide yet.
I removed this and hooked the sound up with the RC mode using y harness so I could see servos move when signal sent to sound card, when its turned on it has a solid blue led, ok so remove battery from receiver and blue led flash's quickly meaning lost signal, plug batt back in and solid blue led.
a bit of testing and troubleshooting ahead of me but any ideas would be great
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The behavior you describe with the LED sounds exactly like what is expected. I'm not sure what is wrong or what you need help with?
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It may be a set up issue, maybe I have not started the engine yet :o
As I said I have not got my serial cables yet so will not panic till I get these :)
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Possibly. Read through the Wiki for the sound card to be sure you have not missed anything. Note the procedure for using it in RC mode is different then when controlled by serial via the TCB. In RC mode you must place all your settings in an INI file on the memory card, and there is a separate utility provided to help create this file. Again, there is documentation in the Wiki.
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Ok, set up the ini file etc, I'm still not getting any sound.
What is the speed difference between a hearbeat/slow flashing and a fast error flash?
Mine is about 1 sec on 1 sec off speed rate, is this normal or error? reason I ask is that it does not change when I pull the sd card out and this should cause an error
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attached a screen shot of my sound during test, only one file loaded on SD card, looks ok but no sound ???
(http://i206.photobucket.com/albums/bb21/pandknz/screenshot%20of%20sound%20test_zps12nyuh4r.png)
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- Please use the attach image functionality of the forum to post pictures, rather than putting them in Word documents
- It looks like you are trying to play the sound using the Test feature with a jumper on RC input 1, is that correct?
- When you are viewing debug information from the sound card (or any other OP device), do not use the Connect button - instead use Snoop.
- Make sure your sound file is encoded as 16 bit 44,100 Hz. Open it in Audacity or some other audio program to confirm or convert it if need be.
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Thanks Luke, fixed the file.
I've double checked the wave files and they are ok, run it through the test again in snoop mode and it runs without error, I must have a bridge or something after the processor, maybe through the amp circuit, I will do some testing on the circuit and let you know what I find
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Yeah, the amplifier IC on that board is about the only component susceptible to shorting, but it would not be hard to do.
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Ok, have not had much time to check the sound card but the USBasp came in so I hooked this up and I am getting an error
(http://i206.photobucket.com/albums/bb21/pandknz/test_zpscgzofpw4.png)
when I google the error it seems quite common with the USBasp's from ebay etc, how do I upload new firmware?
Also, before I upload the bootloader should I have any LED's on or flashing? I dont have anything even with a Batt connected.
When I try to upload the firmware I just get a message that relates to the clock settings.
Any ideas?
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I don't think you can change the firmware on the USBASP itself, probably you are experiencing a Windows driver issue. Try using the Zadig libusb driver installer (http://zadig.akeo.ie/), see this page (https://rayshobby.net/wordpress/dead-simple-driver-installation-for-usbasp-and-usbtiny-on-windows/) for more. Anyway this is what I have always used.
There is no point trying to flash firmware to your Scout until you have the bootloader installed, so the fact you got errors in OP Config is to be expected.
I don't think you will see any LEDs or activity on the Scout before the bootloader is installed. After the bootloader, you will see the red LED blink slowly. Also - you should apply battery power to the Scout board while trying to flash the bootloader, the USB is not always enough to get the job done.
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Hi Luke
Thanks for the info, I have been using this software, I just tried using my laptop just in case it is my PC (Windows 10 64bit) and it came up with the same error message, but a bit more reading on this fault and a lot of people said just to ignore it as its a warning only and it should work fine, so I tried the firmware again and it went 5through 100% no errors, strange?? :o
So was it my PC or was it the fact I put new drivers into my laptop, who knows till I build a second scout (parts on their way).
Good News is that the scout is working 100% perfectly, just need to fine trim the radio as it is getting a little bit of drive in neutral which I used the fine trim on radio to smooth out.
I forgot that when I set up the radio I set it up with a 3 pos switch to control the gearbox, at first I thought I had a problem as it would not reverse...penny dropped in a few seconds ;D
So all is well, just need to get sound from my sound card and I am a happy Tanker 8)
Will post a picture/video when I get the sound working
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One other thing, Ive looked through the wiki but cant seem to find the info, when I connect the scout to the TCB via serial cable it runs tx-rx rx-tx and gnd to gnd which is normal but when I add the sound card it runs from TCB to sound in the same way but the sound out to scout is now tx-tx rx-rx gnd-gnd, it wthis just because its a passthrough?
All three are working as far as radio to TCB, TCB to sound and sound to scout as far as the lights are concerned, signals on and off etc when the motors turn, I will hook up the turret next but still no sound :-[
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Good job on the Scout, and I'm sure it's rewarding to have something work that you assembled with your own hands.
The serial labels on the Scout and sound card are relative to the TCB - so TCB TX-O (transmit out) will always go to the Scout/Sound Card RX-I (receive in) for example. I suppose you're right, the labels may look a bit odd from the sound card to the Scout, but the Sound Card is designed so you can connect the TCB to either one of the connectors, it doesn't matter which, so both labels on the Sound Card are relative to the TCB. But yes you are correct, the signal is simply passed straight through from one connector to the next.
From your description it appears your sound card is functioning more or less correctly, but you probably have an issue with the amplifier chip. Typically you will see the orange LED on the Teensy lit up when it is playing a sound file, that is another thing you can check.
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Ok, round 2 of building the sound card, with the amp chip is the little triangle line up with the dot on the board at the bottom right looking past the speaker?
This is how I did the last one but want to be sure this is not my issue
Cheers
Paul
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Yes that is exactly correct. There is a little triangle cut-out on the bottom pad of the chip, on my chips there is also a little cross on the top of the chip at this same corner, these align with the dot on the board on the lower-right side as you mention.
The main thing is not to get too much paste on that footprint before you reflow. You want good coverage, but the layer of paste should be very thin.
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Hi... i like to follow ur build...and as i go through this TCB and Scout..feel really wanna build but i don have all the expertise n tools to build it...
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Hi, its a bit of a challenge but you just need to take your time with it, I got my Scout done first time and had a slight issue with my sound card but I'm doing another one today so I will let you know how I go, I will use the 1st sound card on another model if I work out what went wrong, its strange, it seems to work but I don't get sound so I think its the amp or another part of the output that has the issue. Funny because the Scout was harder :)
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Hi Baeng, I recommend anybody who is not already experienced with reflow soldering to not attempt to assemble these boards. There is too much that can go wrong and I can't support hardware that others built.
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Yes, I agree with what Luke has said, when I said Its not too bad, I've done a few circuits and I'm comfortable with what I'm doing but as mentioned still got a mistake, still have not had a chance to do the second sound card, will do it when life slows down, I have run the Stug though and its a dream to drive with the TCB and scout :)