npitech

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Everything posted by npitech

  1. I received my Papilio (250k) a short time ago and started to go through the documentation then discovered I needed a MegaWing. It arrived today so I went through the steps and programmed the board with Switches_LED.bit. All of the 7-segment displays lit up and none of the switches control any of the leds (all off). Double checked everything and went to the forums where I find someone with a similar problem. There was a note about changing the code to address different pins (MSB vs LSB). Tried that; no change. Tried Quickstart-Papilio_One_250K-v1.5.bit; all even-numbered leds blink, switches do nothing. I noticed that the behavior changed if I touched some of the pins near the switches. I could move my fingers around and get one, two, or three of the leds to stop blinking. Seemed to me like one of the supplies needed some more capacitance. Used my o'scope to check the supplies and found 5V was clean, 3.3V had about 400mV of a sawtooth and the 2.5V had a smaller amount of the sawtooth. Touching the scope probe to various pins causes different leds to stay on. The sawtooth changes from 20kHz to 47kHz at what seems to be the same rate as the leds turn on and off. I inspected all of the solder joints on both boards, I didn't find any cracked joints. There were a couple of solder splashes on the MegaWing (not mine, I only soldered the connectors on the Papilio) and a large blob of solder wicked up on the leads of C3 but otherwise, the board looked good. Any help? PS. Won't be online tomorrow --
  2. npitech

    Just received my board -- problems!

    Thanks All. This morning I edited the UCF to put the pins back to match the documentation (vs. the re-ordered pins to flip the msb/lsb) and suddenly I can toggle the switches and get the LEDs to turn on. I do not know what changed, in both cases I cut-n-pasted the text in the file but it looks like I can now proceed to learn more about these pesky fpgas. I'm an rf & uwave guy. thanks again!