I'm wanting to use this TPIC6A596 Shift Register to drive a 12v LED matrix but not sure where my 12v+ feed should go. I've searched the web and can’t find any schematics. I have the data sheet but even that doesn't clearly indicate which pin should get the feed. Data sheet here: Please could anyone advise me as to how I would build two of these into a circuit and managed from the Arduino using 3 pins? Many thanks
The 12V feed goes only to the anode ends of the LED/series resistor pairs whose other ends are connected to the drain outputs of the TPIC. The TPIC itself only needs a 5V supply.
Data sheet here: http://www.ti.com/lit/ds/symlink/tpic6a596.pdf
I've bitten off more than I can chew with this project, it's a Christmas display for a gift. I have the LED board made, 650 LEDs all linked up in an 8x8 grid and have the correct resistors to get maximum brightness. The LED panel works very well when power is directly applied. All I need now is to get the 12v power feeds in via the shift registers, I'm multiplexing so as to run a PONG game from the Arduino. I've been on this project for over 6 weeks (100+ hrs in total) and running out of time.
Any help to get this game running over the next couple of days would be really appreciated. I'm new to electronics and well out of my comfort zone. PLEASE HELP... :~
dc42: The 12V feed goes only to the anode ends of the LED/series resistor pairs whose other ends are connected to the drain outputs of the TPIC. The TPIC itself only needs a 5V supply.
Many thanks for the speedy reply.
OMG - Are you saying I cant use this SR to send out 12v+ via the 8 pins?
I need to get 8x12v+ and 8x12v- multiplexing to my board.
Are you able to tell me what I need to do to get this pong game working?
You can’t directly use the TPIC to provide +12V to the matrix, but you can use each of its drain outputs to drive a pullup resistor and a P-channel mosfet like this:
TPIC drain → mosfet gate and one end of pullup resistor
+12V → mosfet source and other end of pullup resistor
mosfet drain → provides +12V to the matrix
Any P-channel mosfet that can switch the total current involved (i.e. 8 LEDs) should do, it doesn’t need to be a logic level one because it is getting 12V gate drive. The pullup resistors can be 1K.
PS - you’ll need to drive the TPIC outputs LOW to get +12V output from the mosfets.
Is there any chance I can use a TIP127 PNP transistor connected to the arduino and sending the arduino pin LOW with a 1k resistor in between to get the 12v+ across? Just as this does the ground : http://thecustomgeek.com/2011/08/01/controlling-high-power-or-high-number-of-leds-with-an-arduino/
I have these available to me tonight. TIP127 x8 and 8x TIPC13G for the NPN's, I could then use 16 pins from the arduino. Would this work? Thanks for the advice so far, very helpful.
For the +12v supplies to the matrix, you would have to use a small NPN transistor (e.g. BC337, 2N3904) and 2 or 3 resistors to level-shift from 5V to 12V, feeding a PNP transistor (TIP127 would be OK) to switch the 12V. Alternatively, one of these http://uk.farnell.com/micrel-semiconductor/mic2981-82yn/ic-source-driver-array-8ch-500ma/dp/1311028 will do all 8 channels.
The TPIC is fine or driving the cathode lines of the matrix (through suitable series resistors).
If you have the TPICs already, you could use them to drive TIP127s instead of the mosfets I suggested.
Do I detect that you are in a hurry to get this working?
dc42: Do I detect that you are in a hurry to get this working?
Ive spent every spare day for the past 6 weeks trying to get this working. I did have it working at one point but not enough power was getting through and the LED's were dim. It taken over my life, and my dining room. I need to get this working in the next few days.
I have a pong game code using 16 outputs from the arduino and code for 2 shift registers. Both codes work, i just need to get the 12v power to the board of leds. When i setup a simple 5v circuit and drive it from the arduino everything is fine.
I need to find the best way (and a way i understand as a noob to electronics) to get this lit up.
I sent you a PM, if you would consider allowing me to telephone you for some direct advice I would be extremly gratful.
Looks like another very long night going round in circles.
All the best, Phillip
Here is a list of items i have to hand, If you could draw me a quick schematic it would be very helpful...
TIP31CG X10 TIP127 X 10 BD139 X 9 BC548B X 20 2N5401 B331 X 15 TIP107 X 2 TIP102 X 2 IRF540N X 2 IRF9540N X 2 TPIC6A596NE X 5 TPIC6B595 X 5 MAX7219 X 8 74HC595 X 5 LOADS OF RESISTORS AND DIODES
Can I make anything with this lots? Please, if you have time, draw be a schematic, rough by hand would do.
Many thanks, Phillip
dc42: If you have the TPICs already, you could use them to drive TIP127s instead of the mosfets I suggested.
This line saved my life :) I have put together a circuit which works very well. I will get a schematic drawn up later today to show you how i did it. Your opinion on resistor sizes would be helpful once I have drawn it would be appreciated. I cant thank you enough to the nudges in the right direction. Turns out simpler than i expected.
All the best, Phillip
PMKimpton: I have put together a circuit which works very well. I will get a schematic drawn up later today to show you how i did it. Your opinion on resistor sizes would be helpful once I have drawn it would be appreciated. I cant thank you enough to the nudges in the right direction. Turns out simpler than i expected.
All the best, Phillip
I was searching for almost this EXACT thing, and I was hopeful that he schematic would be posted. Reminds me of https://xkcd.com/979/
I'm learning as I go while reverse-engineering an ancient-design of a gym clock (HEF4094 driving LED chains in both serial and parallel using 15v) which means I'm on an unsupported path using outdated technology/
I'm not going to provide details here and hijack an old thread... just remarking how desperate I was for this example, and how frustrating it is when people don't pay it forward by posting their answer. :(
Seems you want a PNP darlington switch high-side (switching the +15volt line), with a TPIC driver.
Emitter to supply(+), and base via a resistor to a TPIC output. Collector powers the load (LEDs). Resistor value should be calculated for a base current 1/250 of the expected max collector current. Leo..