Yes that is right. Just like on my post #242. What can i say other that chances are i am not going to use it on the circuit after all.
Are there any other direct replacements or will you have to redesign the board?
Yes that is right. Just like on my post #242. What can i say other that chances are i am not going to use it on the circuit after all.
I am not sure about that John.Are there any other direct replacements or will you have to redesign the board?
So far only receive i need but thanks anyway.You don't need one when only receiving data to a Picaxe. However if you need to transmit RS232 level data you may want to check these Intersil chips..
Chris
No that i have not done. Only unused picaxe pins are pulled down. Could that be the reason ? O.K. here we go testing againI forgot to mention this but before abandoning the MAX chips make sure you have all unused inputs tied low or high as per manufacturer's spec. Or have you already done that and I've simply forgotten?
If you are getting tight on space, two suggestions:1. With your through hole resistors, go vertical, or 1. Consider a surface mount resistor chip - they are small and easy enough to work with at 0805 or higher sizes. 0603 might be challenging the first go around.Yes because there is no space on the PCB. I think that transmit pins dont need to be pulled down.
Ah! You have already used that trick!! Can you take a picture of the copper side of the board? I have the last picture from the other thread: PCB buildingI have already fitted four 0402 smd resistors under the max3232 ! I may be able to fit two more though. It is just that signal lines are in the way. I am sure i will find some space for two more.
If you are getting tight on space, consider using a pad on the copper side by the pin and solder a jumper wire to a remote location that has ground plane.Well i haven't made it yet. It should be ready by tuesday though. I am still thinking what improvements i can make based on the first PCB.
I think i found a solution that works.
So far i had no falures with this design.
10K pulldown resistors to all unused inputs and outputs and a 20 Ohm resistor in series with the supply rail feeding pin 16.
LT Spice IV. Also check out Tina-TI at the Texas Instruments website,
Chris
I think i found a solution that works.
So far i had no falures with this design.
10K pulldown resistors to all unused inputs and outputs and a 20 Ohm resistor in series with the supply rail feeding pin 16.