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1  Forum 2005-2010 (read only) / Development / Re: Library for TLC5940 16-channel PWM chip on: July 15, 2010, 07:37:43 pm
There were some people mentioning in this thread that they were trying to control small vibrating motors with the TLC5940. Did anyone had any results? I am trying to do the same with some of those that are 2,3 V and 85 mA. I need to hook up 16 of those. Although I can control their intensity-speed when I try to use the fade functions they don't seem to respond.
any ideas??
2  Forum 2005-2010 (read only) / Interfacing / Re: TLC5940 + small vibrating motors + issue on: July 25, 2010, 06:34:13 pm
well the ground from the arduino to the the whole circuit:

3  Forum 2005-2010 (read only) / Interfacing / Re: TLC5940 + small vibrating motors + issue on: July 25, 2010, 06:04:24 pm
well I tried with the 5V and it is working currently!
although it still doesn't make sense to me why it was working without the ground cable?  smiley


 thanx Richard!!!!
4  Forum 2005-2010 (read only) / Interfacing / Re: TLC5940 + small vibrating motors + issue on: July 25, 2010, 05:50:14 pm
btw (hopefully I am not becoming redundant) I am using LEDs currently
5  Forum 2005-2010 (read only) / Interfacing / Re: TLC5940 + small vibrating motors + issue on: July 25, 2010, 05:49:02 pm
True I am using the Duemilanove.
But how is it possible to just work without the ground present?
6  Forum 2005-2010 (read only) / Interfacing / Re: TLC5940 + small vibrating motors + issue on: July 25, 2010, 03:27:13 pm
Well with the above schematic I have sth really strange. Firstly for the moment I use leds instead of vibrating motors other than that the schematic is the same. The weird is that the setup doesnt work unless I dosconnect the ground from the arduino !?!?!?
It really drives me crazy! any suggestions? I have triple check the connections and they seem correct. (I use a breadboard, nothing is soldered)...
Any help??
7  Forum 2005-2010 (read only) / Interfacing / Re: TLC5940 + small vibrating motors + issue on: July 25, 2010, 05:52:34 am
Hello people,
I hereby attach the schematics of my set up. I would really like your opinion about the connections (decoupling, diodes etc).
Without diodes and decoupling while I was testing I had some weird inconsistencies like breaking the serial communication between the arduino and the computer among others. So I would like to know if what I am planning make sense.  :-/

8  Forum 2005-2010 (read only) / Interfacing / Re: TLC5940 + small vibrating motors + issue on: July 19, 2010, 06:43:20 pm
Grumpy Mike thanx a lot now it makes much more sense!
you saved the day,
cheers!
9  Forum 2005-2010 (read only) / Interfacing / Re: TLC5940 + small vibrating motors + issue on: July 19, 2010, 06:17:16 pm
The case is that I use a fio arduino which gives 3.3V. So I was wondering how to calculate the the current in the output of the chip given the 3.3V supply. Further more how I could step it up in order to feed the chip with 5V. Is it more clear?
10  Forum 2005-2010 (read only) / Interfacing / Re: TLC5940 + small vibrating motors + issue on: July 19, 2010, 05:28:02 pm
Grumpy_Mike you are perfect!

with 1100[ch937] I am taking around 26[ch913] and a some movement.
So with a resistor at around 640[ch937] it will be theoretically ok if the dissipation is not very high correct?
how about if I use sth like a heat-sink for the chip?
I have one more question how in the chip is connected the voltage input in the chip with the output current and the resistor?

11  Forum 2005-2010 (read only) / Interfacing / Re: TLC5940 + small vibrating motors + issue on: July 19, 2010, 05:01:32 pm
that is from the data sheet of the motor
Voltage Range [V] 2.5~3.8
Rated Current [mA] 75
Start Voltage [V] 2.3
Start Current [mA] 85

what is 32 and 1.24 in the formula?
12  Forum 2005-2010 (read only) / Interfacing / Re: TLC5940 + small vibrating motors + issue on: July 19, 2010, 04:52:34 pm
actually once again u r right!
I screwed the connection with the diode. so I removed it in order to measure properly. it gives me around 3mA which is far to low to drive the motor. So probably I have to use sth like a 320[ch937] resistor right? the data sheet of the motor mentions 75[ch937] terminal resistance.
13  Forum 2005-2010 (read only) / Interfacing / Re: TLC5940 + small vibrating motors + issue on: July 19, 2010, 04:35:52 pm
yeah of course u are right typpo!
I mean 75 mA!
14  Forum 2005-2010 (read only) / Interfacing / Re: TLC5940 + small vibrating motors + issue on: July 19, 2010, 04:28:34 pm
btw the lack of PWM on the 74HC595 made me to abandon it.
15  Forum 2005-2010 (read only) / Interfacing / Re: TLC5940 + small vibrating motors + issue on: July 19, 2010, 04:27:51 pm
Probably that is the part I am missing. I am using a 10K[ch937] resistor currently. I have connected only one motor and my meter shows 75A. is that make sense?
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