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koossa
- 6th May 2005, 13:49
Good day Picers

I have connected a RFID Scanner module to a pin on my pic, but the module needs 30mA and the pic only supplies 25mA, would it be a suitable sollution if I connect 2 pins of the PIC together to get 5v @ 50mA?
Would there be ANY side effects if I do this?


Thanks
Koos

mister_e
- 6th May 2005, 18:06
yiiiish, in theory it can work but i'll not using that. I'll for sure use transistor, mosfet or buffer/driver instead.

Ingvar
- 9th May 2005, 08:30
Why not? Just make sure that you set and reset the pins at the same time. This means that the HIGH and LOW commands is out of the question. Always access the port in a bytewise manner.

Melanie
- 9th May 2005, 10:48
Even at 4MHz, the difference between adjacent HIGH/LOW commands is only a couple of uS. If you're driving a Relay, LED or Lamp requiring that current, it's really not going to know or care for that short time span. Do however protect the PIC with additional Diodes to clamp the back-emf if you're driving a Relay or Solenoid directly. If you're powering-up an electronics module, I still don't think it'll care about a supply rise across 5uS or so... hell, even the best PSU's in town don't come up that fast!