Inverting clock signal

[joshnz]

The situation is this, the micro controller inbuilt serial interface is setup to to clock with high to low and the time keeping chip is low high.
Anyway here is my solution provided in the attachment.

[Rob Northen]

Re: Inverting clock signal

74HC14 chip ??
Or mabye I'am totally lost

[Agent24]

Re: Inverting clock signal

I think you could just use a single transistor design but depending on your clock frequency beware something like a common BC547 may not switch fast enough.

Probably better to use an inverting buffer IC like Rob suggests.

[joshnz]

Re: Inverting clock signal

A ic would be nice but would be a waste most have 4+ and I only need 1.
How ever I will try the bc547 if it is too slow I will find out.
The max clock the RTC can take is 2MHZ the serial is set to 300bps

[Rob Northen]

Re: Inverting clock signal

A ic would be nice but would be a waste most have 4+ and I only need 1.
How ever I will try the bc547 if it is too slow I will find out.
The max clock the RTC can take is 2MHZ the serial is set to 300bps

It has 6 in/outputs

[Longbow]

Re: Inverting clock signal

What is the clock frequency? If you only need to invert the clock, you might find that your uPC already has an inverted clock port already. If not my observations: BC547 is a g.p. transistor. You should be using something designed for switch operation. A 100K resistor in the base is too large, because it starts to be a problem because of stray capacitance on the traces and the transistor. With a 5 volt system, a 100K base resistor will pull about 43 uA from the base. That is far too low to get this transistor saturated. I suggest 10K or below. The collector voltage should be around .2 v. if the transistor is saturated. That's what you want.

[joshnz]

Re: Inverting clock signal

Well So far I have tried software serial it works if I heavily load the Sclk line and with the hardware serial at 300bps I get no usable data.
I am currently on holiday in Christchurch for Christmas Had my mums mum pass away on the 19 went to her funeral on the 21 (I came to Christchurch with mum after the funeral)
And on the 23 were hit by two large earthquakes of 5.8 and 6.0.
mum didn't take both of those to well but we had a good Christmas today

[joshnz]

Re: Inverting clock signal

I'm back my next thing i am going to try is a much much lower clock signal.

[joshnz]

Re: Inverting clock signal

Went back to bit banging working now so didn't need to invert the signal the code was backwards fixed that now getting the time off the DS1302+ via The PIC16F727.
Have one issue and that is writing to the DS1302+ will look the code over some time and see why.

A funny thing happened earlier and that it was displaying 30:53:25 did not know there was a 30 00 in 24 hours I reset it to 24 hour time and set it to the current hour it went from 23 00 to 0 00 now 3:01:24 so later wen i get up i'll see if the time is still valid.