Are there any considerations required for the transistors? Also if i light up segments to say display the number '8'. Do i calculate each segments current to get the overall current?
Hi
I have a 4 x 7 segment common anode display, which i will be driving from a PIC micro.
I need some help in calculating resistor values and selecting the correct PNP transistors.
Can anyone help?
Thanks in advance.
Hi
So am i correct in saying that the pull up is tied to VDD via an PMOS FET internally? A logic 1 will keep the MCLR high. A logic 0 will turn on the PMOS FET and short drain to source to 0V.
Is that correct?
Thanks.
I wanted to ask what actually happens internally to the MCLR line of the PIC i.e. in terms of the FET/transistors.
Is there any good sources to explain this?
Thanks in advance.
Hi,
I have a reset pin of a PIC micro connected to 5V via a 10K pull up resistor.
If i connect a I/O line of a second PIC to the reset of the first PIC. Can i reset the PIC by outputting a zero? Or should it be a logic 1?
Thanks
Hi all,
The TX and RX coupled with a reset allows communication to the z wave module.
There is a set time after a reset that the module will look for a sequence of transmit pulses, from this it can recognise that it requires programming.
If the RESET line is pulled high with a pull up...
The application requires us to be able to reset the micro, before initiating data transfer via UART. It is for a ZigBee application.
What would be a software reset function on a PIC mucro 18F series?
Thanks in advance.
Hi Harald
Many thanks for your help.
I was going to use something similar but without the RC filter. So a pull down from the gate and a resistor from gate to MCU I/O line i.e. like the 1K you have used in your circuit.
I still really want to understand how we calculate these resistor values...
Hi all,
I am using a PIC18F4520. I need to be able to control the reset/MCLR line (which at the moment is pulled up via a 10K resistor to VDD 3.3V).
I need the control to be software driven rather than have a switch from the pull up to 0V.
What would be the best way to do this?
Could a Logic...
Hi,
I am trying to understand what happens 'internally' (on a hardware level) to a PIC I/O line when it is configured as an input / output or high impedance.
I know that there are N and P channel FETs which are set accordingly when the port is set i.e. to sink or source current.
I need a better...
I have but some use obsolete parts. I was looking for a quick, cheap and easy schematic. That can be knocked up with readily available components. Dont need any microcontroller type.
Hi i am after a schematic for a frequency/waveform generator. Adjusable frequency and amplitude for sine, square and ramp. Upto 100KHz.
Something which is easy to build.
Any ideas?
Hi all
I am using a PIC which is connected via a 3 way connector. The connections are from PORTB of the PIC. PIC is powered from 3V.
I want to know what is the best way to protect the I/O lines of the PIC in case the user accidently applies too much voltage on the connector end.
Could i use a...
Thanks for the info. I really thought that mcd was how much the led was outputtcloseing. I thought it was the more current through the led the closer it gets to the mcd stated on the datasheet.
I need a led to light through some plastics. 35mcd was not good. But i found a 220mcd and with the...