greetings,
I'm using an arduino mega 2560, I need a clock signal to drive an HCTL-2020 decoder, Atmega 2560 has a clock pin (CLKO), but I don't find the equivalent I/O port on the arduino ports, because isn't connected to any arduino port, so, Should I do any soldering stuff on the top of the atmega chip to get a clock signal ?
or how a get a clock signal from the arduino to drive HCTL-2020 decoder.
I attached HCTL-2020 datasheet
HCTL2O2O.pdf (337 KB)
The pin wasn't broken out, so if you need to use it you would have to try to solder a small wire to the correct pin (pin 9 I believe). The IC is 0.5mm pitch, so it is a pain in the rear, but it is possible. When i soldered to one of the pins before I used a single strand of copper (about hair width) taken from a piece of twisted core cable, and then soldered a blob between the wire and pin, then used solder wick to make sure there weren't any shorts to adjacent pins.
In your case, you could get away with soldering pins 9 and 8 together and to your wire. As long as you ensure that you include this as the first line in your code:
DDRE &= 0b10111111;
which will ensure it remains an input and thus wont short out the CLKO.
What clock rate? You can set up one of the timers to output to a pin, with a prescaler of 1, and a count to 1, that gives you a clock output half the frequency of the processor clock.
Don't cross-post please. Threads merged, duplicate post removed.