kenemon 29 Posted June 30, 2011 Share Posted June 30, 2011 As many nightmares evolve, I find myself alone in a state of terror with my MSPG452 project. I look to you guys for some comfort I have a basic input/output project that functions perfectly on the stock launchpad... The code is not the issue, the problem lies in my lack of EE experience... I have been working at this for about 6 months (learning and getting favors from my friend the programmer) : https://docs.google.com/leaf?id=0B0GvwGrWV7TpMmYxZTJiMWYtODFhYy00MjBhLTg0ZmMtMjEzYTk0OTQzZDk2&hl=en_US&authkey=CKuFiLsL I picked up some expensive FR4, they are pretty and have "cuttable" connections between all the positions. A little bit of a pain at first, but I can appreciate the idea- less jumpers and solder. You need a brand new utility blade for starters, and a good layout in mind. You can see an issue with the couple of wires on the face. https://docs.google.com/leaf?id=0B0GvwGrWV7TpMmNjZTM4M2ItYzMzMy00ZDQwLTgxODUtZmViNWY2ZmNiMTU0&hl=en_US&authkey=CIXgxdsG this progressed to a much prettier prototype (took about 2 hours): https://docs.google.com/leaf?id=0B0GvwGrWV7TpYjVmNmM3NzMtZGFmOC00NzMzLTk3OGQtNjI3YmUwNTM3YTUx&hl=en_US&authkey=CL3Yj4QD It was heartbreaking when it did not work, nothing happened. Then Ken Finnegan alerted me somewhere in his many posts that the standalones need to have the reset taken up with a resistor or it will continually reset. Thanks Ken (great name by the way). Done, and i had some flashers. Unfortunately, the inputs and the outputs are not working like on the LP. I have traced all my connections, and checked for shorts and gaps, and found nothing. I am able to hardwire the inputs, using a jumper, a switch, or my finger, but for some reason, the P1.0 input will not trip the interrupt now- but all the others work (P1.1-P1.3). Your comments are welcome, please! Quote Link to post Share on other sites
oPossum 1,083 Posted June 30, 2011 Share Posted June 30, 2011 It is good practice to have a 100 nF (0.1 uF) capacitor across the power pins. That may not be your problem, but it would be good to add one just to rule that out. kenemon 1 Quote Link to post Share on other sites
RobG 1,892 Posted June 30, 2011 Share Posted June 30, 2011 I always pull RST and TEST pins up, through resistor or directly to Vcc. And as oPossum already suggested, cap is a must, but I usually go higher, 10-47uF electrolytic. kenemon and MarkoeZ 2 Quote Link to post Share on other sites
kenemon 29 Posted June 30, 2011 Author Share Posted June 30, 2011 Thanks RobG, I fixed that mistake. One of these days I will get the terminology right. The resistor is hooked up as you suggested Quote Link to post Share on other sites
kenemon 29 Posted June 30, 2011 Author Share Posted June 30, 2011 thanks oPossum and RobG, I will try the capacitor... Quote Link to post Share on other sites
zeke 693 Posted June 30, 2011 Share Posted June 30, 2011 This is what I do: Note: all the I/O's are unassigned in this diagram. kenemon and MarkoeZ 2 Quote Link to post Share on other sites
kenemon 29 Posted June 30, 2011 Author Share Posted June 30, 2011 thanks zeke, that Is a great reference. All seem to agree on the cap, which i will add momentarily. Can you tell me what OR means please. I am going to include a jumper as you show so that I do not need to keep switching the chip out (it was on my todo/tofigureout list ) P.S.- how do you put the images directly in the post. I tried the button (Img) above, and put in the link, but it didn't do anything. Thanks again. Ken Quote Link to post Share on other sites
bluehash 1,581 Posted June 30, 2011 Share Posted June 30, 2011 Can you tell me what OR means please. It's not OR, it is 0R or zero resistance. Meaning a short - used instead of a jumper. kenemon 1 Quote Link to post Share on other sites
kenemon 29 Posted June 30, 2011 Author Share Posted June 30, 2011 Adding a .1uF capacitor has not had any effect Quote Link to post Share on other sites
RobG 1,892 Posted June 30, 2011 Share Posted June 30, 2011 Did you enable internal pull up/down resistors on your inputs? Keep in mind that LP has some extra parts connected to pins that may affect your code. kenemon 1 Quote Link to post Share on other sites
zeke 693 Posted June 30, 2011 Share Posted June 30, 2011 Yeah, like BH says, it's a zero ohm resistor. When you're laying out a pcb and you're going to use surface mount parts, you might as well make the design as generic as possible. This will let you use that pcb for a new circuit later on down the road. Putting in a zero ohm resistor will allow you to disconnect the micro from the circuit and then you can solder in something new. Compare your circuit to the diagram. Do you have the reset line pulled up with a 47Kohm resistor? Do you have 3.3 volts connected to pin 1? Do you have ground connected to pin 16? Do you have your chip inserted with the correct orientation? Can you program your chip with the launchpad? If you are trying to program the target board with the launchpad then make sure that you remove the micro from the launchpad. If not then remove all the 0.100" jumpers from the launchpad's spy-bi-wire connector (J2) and then use the 0.050" connector (J4) and connect to your target. Simplify your setup and it will work for you. kenemon 1 Quote Link to post Share on other sites
kenemon 29 Posted July 1, 2011 Author Share Posted July 1, 2011 I am going to try and enable the resistors. A while back this helped me with a bouncing problem. I have hardware debounce now, but I am going to give it a shot. I have checked off everything on your list zeke. I have been programming it on the LP and then hooking up my wiring harnesses to the LP to test it- working fine, I move the chip to the PCB. I am thinking now the problem is with my buttons. I based them on the demo: http://processors.wiki.ti.com/index.php/MSP430_LaunchPad_PushButton It must be the debounce circuit. Curious why it works fine on the LP and not on the PCB :cry: thanks again you guys! Quote Link to post Share on other sites
zeke 693 Posted July 1, 2011 Share Posted July 1, 2011 Can you draw up a schematic of your intended circuit? Post a jpg when you get that done. Quote Link to post Share on other sites
kenemon 29 Posted July 1, 2011 Author Share Posted July 1, 2011 Here are some late night drawings, I will work on some better ones tomorrow... Thanks Using MSP430G2452, detail per aforementioned wiki example Anyone have a schematic program that is free? PCB artist was ok, but schamas were difficult to understand for me :roll: J1=button harness J2=LED Array Quote Link to post Share on other sites
kenemon 29 Posted July 2, 2011 Author Share Posted July 2, 2011 The nightmare is over. After finally making a plan and working out a new board, being careful with everything and checking it twice, I can see the light. P1 resistors enabled. The help is greatly appreciated, and the button debounce works flawlessly (no extra ints). Resistors enabled on P1.0-P1.3. Working with those connected PCBs it not worth it in my opinion, although the product is very appealing to the eye. I will improve on the board with a jumper for programming next..... : Quote Link to post Share on other sites
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