Pearl Posted June 5, 2003 Report Posted June 5, 2003 Is it possible to mount the motorfader with the motors at the bottom instead of the top like shown in the pdf-sheets?Do I have to change only "vss" and "vdd" and/or the "motor-pins" ?Thanx Quote
pilo Posted June 6, 2003 Report Posted June 6, 2003 You will have to change both thing : the motor vss and vdd, and also the pot wire! (beacause if you just change the motor alim pins, it will go up when it has to go down!!!) Quote
Steven_C Posted June 9, 2003 Report Posted June 9, 2003 if you are using panasonics watch out! the resistance when the wiper is at the end with the motor should be close to zero ohms, but on mine I measured 20 ohms! If it all works out well, let me know please!...Steve Quote
Pearl Posted June 9, 2003 Author Report Posted June 9, 2003 I got APLS- Motorfaders, but I will check it.Thanx Quote
Pearl Posted June 9, 2003 Author Report Posted June 9, 2003 Hi ...on my faders i got between 13 - 15 Ohm at the end.With 10-bit resolution we have 10.000 Ohm/1024 makes 9,765625 Ohm for every step. So we have to subtract one or two bits(steps) to get the right result. Is this calculation right and is it possible to do this by the firmware?Pearl Quote
pilo Posted June 9, 2003 Report Posted June 9, 2003 if you use only 9 or 8 bit, you will have only 512 or 256 step...I think, a mod could be to take 5V and -1V and a pot in serial with the fader for ADC... Thorsten? am I right??? to get 0V when the fader when it is at its the end Quote
TK. Posted June 16, 2003 Report Posted June 16, 2003 Hi Pilo,the PIC could be damaged with a negative voltage at an analog inputs, so it would maybe be better to add a shottky diode to all Vss pins of the PIC in order to shift the negative reference voltage by ca. 0.3V - but I'm not sure which side effect can occur thereafter. :-/Best Regards, Thorsten. Quote
pilo Posted June 16, 2003 Report Posted June 16, 2003 A yes, but what I was thinking about is insertinf an offset so il the pot value goes from 20ohm to xkohm, we can have 0V at the mininum (r=20ohm)... but I don't think it's very useful! ;) Quote
Steven_C Posted June 17, 2003 Report Posted June 17, 2003 as a very rough workaround, I have added resistors like this.....________________ +5v rail  | []  470ohms  |  |  | | | | |<--------- 10kohm fader wiper pin to ADC | |  |_|______________ 0v railthis has the effect offsetting the positioning of the fader, but a side effect is that you can only reach a midi value of 123 at top of travel, not 127.  TK, if you put shottky diode between 0v and pins of PIC, I wonder if pic is getting enough voltage? I guess you could hand pick a 7805, as these seem to vary up to 5.3v anyway.  I am setting Logic to work only with bit values of 7 bit anyway, so as to avoid jitter, and occasionally the fader will only go down to 1, and not 0, but this is not really a hassle!BTW TK, I hope you had a great holiday!! I think you should schedule regular breaks from this forum, as you do so much for us already! But then again, I'm not going to complain if someone helps me so much like this!! ;Dbye, from Steve Quote
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.