Jumper to enter setup

[mackrackit]

Make all of the unused pins an OUTPUT and code them LOW near the beginning of your program.

[Charles Linquis]

Again, the method I outline above will allow you to determine if a pin is completely open, or else connected to one of the rails via a resistor.

I had exactly the same case, where a board layout was incorrect. I needed to figure out if a jumper was on or not. "Little green wires" or added resistors were not an option.

I'm not advocating this method for production. But it can fix a bad situation.

[Bobbo_ZA]

Hi Charles,

I will give your option a go tonight, :-), should work for what I need it to do. Was thinking to monitor the pin for a few cycles and if it floated to read it as open and if it was high to read it as closed / Jumper on.

had a closer look at the circuit and I may be able to squeeze a 0402 or 0805 under the PIC's socket from the pin to the GND track, although there are no pads it should solder to the track - 0.25mm track width - if i can get it in there then I would read the pin as LOW for "open / jumper off" and high for "closed / jumper on" :-)

I like your option though as it keeps the compnent count down which is what I was aiming for as hand soldering 0402's is quite a challenge, :-)

Many Thanks

Kind regards
Rob

[Bobbo_ZA]

Error, :-( looked at it last night and cant use the track under the PIC, will have to try the "Slam-read" option which seems viable or use the other PIN and leave that side empty until I have some more printed.

Question to Alain, have you manged to code a section in any programs you could share where you check if the user has a Futaba or a JR TX?

It seems the PIC reads Throttle low-high on a JR as +- 100-200 and a futaba as +- 200-100.

Cheers
Rob