preenfm Forum
PreenFM => preenfm2 and preenfm3 => Topic started by: flocked on November 21, 2013, 05:14:17 PM
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1. You forgot to mention the 330nF capacitor in the bom. Now I need to make a new order for it :/ Or can I use something else?
2. I ordered the encoder alternative PEC11R. Unfortunatly it has 2 pins to much (on the other side). Should I cut them?
3. The mini usb connector (female) looks different. How should I solder?
(http://imageshack.us/a/img268/1755/r1w.JPG)
(http://imageshack.us/a/img822/3843/9ru7.jpg)
Thanks :)
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1. Sorry.. Just added.
I'll leave the text at the top of the BOM page one more week ;)
This 330nF capacitor is used to filter the input 7-9V DC in before the 5V (7805) regulator.
It's not essential at all. Should work without. Can be replaced by anything bigger.
In the worst case put a 100nF here.
2. Yes, the alternative encoder has a switch. And the 2 aditionnal pins are the pins for this switch. You can cut them.
3. Contact 2 and 3 (the one that needs to be plug to the PreenFM PCB) shows up clearly in this PDF :
http://www.mouser.com/ds/2/185/e24000019-36944.pdf
I think you can plug the black part directly in the CERB40 board. Metal parts will make things thicker.
Xavier
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Okay, I finished everything. I still didn't got my display, but it should work without display, right?
Unfortunately I can't get it to work :/ Jumper 1 and 2 are closed.
I uploaded the bootloader and firmware to the cerb40, which worked great (I set a jumper to jump3 and connected a usb cable directly to the mini usb connector of cerb).
(btw. I didn't add any capacitor on the 330nf place)
Now nothing works (except puting it again to dfu).
- If I connect an usb cable directly to the cerb I can't see any device on my computer (if cerb isn't in dfu mode)
- If i connect a 9v 1a to it, nothing happens. I tried so send midi notes to it via the din5 connector, but it isn't working.
- The only thing I can see is my blinking usb storage stick if I connect it to the usb connection.
Any idea why? :/
Oh and for what is the usb connection (not the host one for usb storage)? Only for usb midi or also for powering it without power cable? If also for powering, it isn't working either. :/
Without display it's of course hard to see, if it's running. Should the led blink if it's receive midi notes? And how can I activate usb midi blind without display?
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Yes the USB midi also power the PreenFM.
The Led is currently not used.
Initial test:
. Do the led of the LCD turn on when the PreenFM is power up ?
. Display : have you tried to turn the LCD contrast resistor to the 2 extreme position ?
. Did you remove jm3 after having flashed the firmware ? jmp3 force the PreenFM2 to boot in DFU mode.
. Double check the command you used to flash the bootloader and firmware and do it again. Did you run the command from the zip file ?
To check if the bootlader is correctly flashed.
. see http://ixox.fr/preenfm2/manual/upgrade-firmware/ . Open Jmp3. power up the PreenFM while pressing button 3. You should see the device on your computer exactly as if Jm3 is closed.
To Activate USB midi without display, download the attached "settings.pfm" and copy it on your USB stick in "/pfm2/" folder.
But you should hear sound when sending notes to Din5 input any way.
Let me know how it goes,
If no progress, i'll upload a picture to check the ground, 3.3V and 5V on the PCB.
Xavier
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Sorry for the false alarm, everything is working fine.
Because I still don't have the lcd display, i was confused, if it's working. However USB midi showed me the device on my mac and I could play notes :) Awesome synth.
A suggestion:
Replace the two headers for usb connection with a female usb a connector. I found the process of soldering the cable a bit hard. I destroyed the mouser mini male connector, because the pins were too close each other and I melted the plastic. 0.3m mini usb cables are everywhere available and it would allow to just connect the cable without soldering.
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Ah OK !
I just understood. You don't have a LCD at all....
I thought you didn't have it working. Glad you got some sonds ;)
The first PCB prototypes i had was exactly as you suggestion describe.... It was not very "elegant".
I changed because cheap 30cm USB cables are not that easy to find and it took a lot of space in the case.
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Ah okay. I see :)
I can't wait to get the display. I want to play with it! :D I ordered the black/white from your suggested site.
At first I wanted to order a oled display. This needs a custom display init code. You would only need to change a few lines for it. Else it's hd44770 compatible. Just in case someone is wondering.
Another thing: I personally prefer midi jacks that are soldered directly to the pcb. This minimize the need of cables and work and allows to use the synth without case. It also looks cleaner to me. I checked the pcb and there should be enough room for through hole jacks. :)
Oh and you mentioned on facebook that I could order the case on ponoko/formulor. How? :)
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At first I wanted to order a oled display. This needs a custom display init code. You would only need to change a few lines for it. Else it's hd44770 compatible. Just in case someone is wondering.
Where did you read that ?
All HD44770 display are compatible. I have a PreenFM1 with an OLED display and it does not require any code change at all.
The only change is that it's a bit smaller and need to modify the case around it.
Another thing: I personally prefer midi jacks that are soldered directly to the pcb. This minimize the need of cables and work and allows to use the synth without case. It also looks cleaner to me. I checked the pcb and there should be enough room for through hole jacks. :)
I also much prefer midi jacks on PCB. But with the display connection, it was not possible to have them close to the PCB border.
Oh and you mentioned on facebook that I could order the case on ponoko/formulor. How? :)
Go to the download page: http://ixox.fr/preenfm2/download/
Donwload the PreenFM2 svg file and install Inkscape on your computer.
If you want the whole case in the same color, you can use my svg file directly.
Else you'll have to play with inkscape and the templates downloadable from ponoko.
Create an account upload your file.
Material : Chose Acrylic GS, 3mm. Any color ;-)
Xavier
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At first I wanted to order a oled display. This needs a custom display init code. You would only need to change a few lines for it. Else it's hd44770 compatible. Just in case someone is wondering.
Where did you read that ?
All HD44770 display are compatible. I have a PreenFM1 with an OLED display and it does not require any code change at all.
The only change is that it's a bit smaller and need to modify the case around it.
Now i'm really interested in more information about this boot difference. OLED does not work with PreenFM2.
Could save me some time tomorrow when i try to fix that.
Thanks
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I guess a better question is what's the difference between the preen 1 and 2 display drivers.. 1 worked without a hitch.
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I guess a better question is what's the difference between the preen 1 and 2 display drivers.. 1 worked without a hitch.
Agreed..
But PreenFM1 use 8 bits communication and PreenFM2 4 bits.. which makes the comparison not straightforward.
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umph, that's bad news. I could never get it to work in 4 bit mode on a midibox project but I am far from qualified to debug something like that. Hopefully you will have better luck
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Here is an article about the changed init code: http://www.elcojacobs.com/controlling-an-oled-character-display-with-arduino/ (http://www.elcojacobs.com/controlling-an-oled-character-display-with-arduino/)
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Thanks a lot for this link :)
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Firmware 0.9d + bootloader 1.01 have more conservative timing and should work with more (all ?) LCD display.
http://ixox.fr/preenfm2/download/
Let me know if it works for you
Xavier
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So I now that I've had mine for a couple of days, I have some observations:
Bouncy encoders: I tried bourns and alps ones and both seem to be VERY jumpy and overly sensitve, maybe some aggressive debounce code could be implemented?
Noise when volume is maxed: This disappears when you dial it back a hair from max, its a mid frequency hum/hash. It sounds like there should be a low values resistor in there somewhere since its the kind of sound when you drive an amp too hard
Noise when powering via usb: Some additional filtering/part value adjustment? I'll play around with it but the noise floor comes up a ways when powering off USB. Powered hubs usually have shitty cheapo switching supplies so its always going to be poor quality power
USB/DC power: This is going to get people where the accidentally have it powered from both DC and usb, some fail safe might be a good idea. This was a problem with midibox cores that would take power from USB or externally. The way I dealt with it was to use a DPDT switch have that the jumper wired up opposite to each other so in one position it would turn on from USB power and the other postion, from DC
outstanding job though, great evolution :)
Maybe I missed something but are the schematics up in a non-kikad format? I'd like to see how your power supply is set up since I was fully expecting to go to war with the OLED noise and I really dont hear it. Are the internal signal levels really high?
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I received my black case from Pokono and it looks awesome, however it's missing two holes for holding the front plate. I checked the .svg and it's also missing on it. Now I can't attach it :/
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Bouncy encoders: I tried bourns and alps ones and both seem to be VERY jumpy and overly sensitve, maybe some aggressive debounce code could be implemented?
Have you tried both '12' and '24' encoder drivers in the settings ?
If it still does not work with both values, could you tell me the exact reference of your encoders ?
Noise when volume is maxed: This disappears when you dial it back a hair from max, its a mid frequency hum/hash. It sounds like there should be a low values resistor in there somewhere since its the kind of sound when you drive an amp too hard
Interesting... I haven't noticed that. Will give a try.
Noise when powering via usb: Some additional filtering/part value adjustment? I'll play around with it but the noise floor comes up a ways when powering off USB. Powered hubs usually have shitty cheapo switching supplies so its always going to be poor quality power
Yes powering it up from USB requires good USB power supply. They can be very bad.
That's why i added a DC in in the PreenFM2 ;-)
If you find anything that can improve it, let me know.
USB/DC power: This is going to get people where the accidentally have it powered from both DC and usb, some fail safe might be a good idea. This was a problem with midibox cores that would take power from USB or externally. The way I dealt with it was to use a DPDT switch have that the jumper wired up opposite to each other so in one position it would turn on from USB power and the other postion, from DC
Thanks for the idea.
I tried to connect both my IPAD to USB and a power supply to the DC in. Yeah that's bad.... but that didn't break anything.
outstanding job though, great evolution :)
Thanks :-)
Maybe I missed something but are the schematics up in a non-kikad format? I'd like to see how your power supply is set up since I was fully expecting to go to war with the OLED noise and I really dont hear it. Are the internal signal levels really high?
I just upload a Postscript file in the Download tab (http://ixox.fr/preenfm2/download/).
I'm glad it works well with the OLED. I still haven't soldered the Audio part on my PCB with the OLED display.
Xavier
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I received my black case from Pokono and it looks awesome, however it's missing two holes for holding the front plate. I checked the .svg and it's also missing on it. Now I can't attach it :/
I'm glad it looks good and I'm sorry for this error in the file. I've just fixed it.
Thanks for the report.
I can send for free a crystal clear part now, or a black one in a couple of week. I have to reorder something on formulor/ponoko this W.E.
Let me know,
Xavier
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The 12/24 thing fixed my encoder issues, sometimes I forget I am not above the RTFM rule :P
For the PSU noise, it looks like there is some real estate to play around with, I'll see what I can do. Not a ton of power rail smoothing in this design so some good 'ol heavy handed linear PSU tactics may help.
I'm still curious why the OLED doesnt introduce noise into signal, I'm not a electrical engineer but it's odd that this design doesnt have issues with it and something like the shruthi, it's right in your face despite having a super robust PSU design and this does is not terribly different.
Looking forward to some P2 header love down the road though..
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Good news you have the encoders working now.
I'm still curious why the OLED doesnt introduce noise into signal, I'm not a electrical engineer but it's odd that this design doesnt have issues with it and something like the shruthi, it's right in your face despite having a super robust PSU design and this does is not terribly different.
Really ?
I'm glad it works well :)
If i remember correctly the shruthi use PWM from the microcontroller as audio signal... It's possible that makes it more sensitive to voltage fluctuation.
The voltage reference for the 4 external DACs (2 * mcp4922) of the PreenFM2 are well filtered by 2 x 220uF capacitors which may make a big difference.
That's just a guest.
Don't hold your breath for the P2 love ;)
Xavier
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WRT: OLED
I'll bet that it is a level thing. This really came up with the Curtis part, I was an a unique situation where I could test 3 different filter boards with the same digi board and all the current designs were not that bad but the CEM part was a disaster, noise floor went up 10x.
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The BOM says: "Wall power suply 7 to 9v :"
I tried 7,5v / 350mA - it seems to be too weak. The LCD is flickering. 7,5v / 600mA works well!
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The BOM says: "Wall power suply 7 to 9v :"
I tried 7,5v / 350mA - it seems to be too weak. The LCD is flickering. 7,5v / 600mA works well!
The PreenFM actually consumes 120mA.
It's possible that draining 120mA out of your smaller transformer move down the voltage to much.
With the diode AND the 7805 regulator the voltage need to be at least 7V.
Anyway, i'll add a note on that in the doc.
Thanks a lot for the feedback.
Xavier
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so just to clarify, is it ok to use encoders with push switch
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It is OK.
I have a working PreenFM2 with switch encoders.
You'll have to bend the 2 switch pins and eventually cut them.
Xavier
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hi again can i use encoders with 20 dents instead of 24, will it cause any problems
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hello also i have somme 1n4004 diodes at home could i use one of these instead of the 1n4001 in the bom
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20 dents encoders should work if it uses the same quadrature output table as :
http://www.bourns.com/data/global/pdfs/pec11r.pdf
What model do you have ?
1n4004 can replace 1n4001.
Xavier
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hi these are the encoders on ebay
http://www.ebay.co.uk/itm/121195339728?var=420187086302&ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
any good?
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I don't read chinese so i cannot guess if what is written on the output schema is "clock wise" or "counter clock wise"
I think i remember somoene bought them for the PreenFM1, and the behaviour was a reverse behaviour.
Xavier
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Hi!
I'm assembling the PreenFM2 for a friend of mine who ordered the kit, and I've just noticed that the two 9 pins 10kohm resistors have different codes on them.
one says: "09A1 103G 1246"
and the other one says: "09A1 103G 1317"
just wanted to check if they are both ok to use.
thanks!
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If they were in the Kits they are OK ;-)
The last digits are maybe the date : <Year><week number>.
Xavoer
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Perfect, thanks! excited to build it :)