what am i doing wrong
russ christensen
Posts: 84
ok guys, i have no idea what i'm doing wrong. last night i had a nice simple setup on the ppdb, had the clock running feeding time to the vfd, had the ds1620 feeding it temp, using the fullduplexserial driver to send it data and everything was wired up and working great. i took the vfd off the board last night before i went to bed, and put the ppdb in its antistatic case. this morning i put everything back together just like it was last night, and now i am getting no display whatsoever on the vfd. i've tested voltage from the 5v, i have it, using the ground on the ppdb, i even hooked up a voltmeter to the output pin on the prop, and i'm getting around 1.5v i am assuming because its just not sending any signal atm. does anybody have any suggestions? i've already fried (i think) one ping sensor which i'm getting ready to send back to parallax. i can't be replacing parts (especially expensive ones like the vfd) every week cause i do something stupid. any idea's or recommendations would be greatly appreciated. sorry for my extreme lack of experience and feel free to let me know if i'm breaking fundamental electronic laws.
Russ
Russ
Comments
Check power again, make sure all grounds are OK. VFD's use lots of juice, so check batteries if you are using them.
Verify the correct program is loaded into eeprom. Maybe it was only in RAM.
Double check your connections. Look at where the wires are attached too.
Test the VFD power on the VFD itself.
Make the Prop cycle the pin you are using, 1 sec on/off. Check that it is getting to the VFD too.
If the VFD has a test mode, try it.
Jonathan
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www.madlabs.info - Home of the Hydrogen Fuel Cell Robot
Can you post a schematic? ...or take (a) clear closeup picture(s) of your setup?
Also, please provide the code that you are running as well.
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Beau Schwabe
IC Layout Engineer
Parallax, Inc.
russ