Just wanted to post about how handy a logic analyzer can be. Last Saturday spent several hours trying to debug why the SPI output to a HT1632 LED controller was working on my Arduino but couldn't get it working with my PIC. After spending a few minutes with the logic analzyer and decoding the bits coming up from the PC that were true SPI, I then connected it to the Arduino and noticed the output there was NOT SPI per the LED documentation but just simple bit banging. This also identified my ouput was noisey and not correctly switching the bits states to low. After sorting out the output settings on the PIC and switching the port to the correct output mode, I can now finally communicate with the LED controller. Definitely recommend the USB SX module... good price and great features (including 1wire, SPI and I2C decoding.)
Saturday, December 12, 2009
Friday, December 4, 2009
Feeling pretty good right now, just finished soldering one of the hardest devices I have ever done so far... A Microchip PIC18F97J60 100pin TQFP surface mount PIC. Used the solder wick method, and only issue I had was one pin near the bottom shifted a bit due to too much pressure with the solder wick. However was able to move it over carefully with a needle and the PIC fired up and is running my program. Now whether I find one of the ports dead 6mos from now is another story... The pins are about the size if the "I" in the word "LIBERTY" on a penny.
Thursday, December 3, 2009
Just a heads up for those putting the boards together... I hope this will save someone else's sanity :-) Make sure there are jumpers on both P20, and K1 (pin 1 and pin 2.) P20 enables the 12v side to enable receive and transmit. K1 controls transmit, so if pin 1 and pin 2 are open (not jumpered), it will instantly get stuck in transmit. After a couple of hours of frustration, I remembered this the hard way...