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Forum Index : Electronics : Picaxe 28X
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Downwind Guru  Joined: 09/09/2009 Location: AustraliaPosts: 2333 |
There is nothing wrong with the Peek and Poke commands and the addresses used are valid for both x1 and x2 chips. Its not a problem to reprogram a chip over another program as all the previous program is removed in the process and even the eeprom is cleared. Removing power or reset, will clear all data in variables but not the data stored in eeprom. It would seem with Version 2, values need to be set in the menu before the program will function correctly, this would be because the menu settings are stored in eeprom and after loading the code into the chip all the eeprom locations will be set to zero untill new data is entered via the menu. To reverse OP1 i think you should leave the <> unchanged and just change the High / Low commands around. Pete. Sometimes it just works |
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| scnarine Newbie  Joined: 17/06/2011 Location: United StatesPosts: 29 |
Thank Pete...that worked. |
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| scnarine Newbie Joined: 17/06/2011 Location: United StatesPosts: 29 |
This project is coming along great. I will post a picture of the finish product soon. I do have one last question guys....If I used an allegro for the current sensing circuit, would I still need the op amp 741 circuit? |
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| Downwind Guru Joined: 09/09/2009 Location: AustraliaPosts: 2333 |
The short answer is no you dont need the opamp, but perhaps a link to the allegro sensor you intend to use would help with a better answer, as some of the smaller chips do need an opamp but 90% dont. Pete. Sometimes it just works |
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| scnarine Newbie Joined: 17/06/2011 Location: United StatesPosts: 29 |
This is the one I intend to use http://www.allegromicro.com/Products/Current-Sensor-ICs/Fift y-To-Two-Hundred-Amp-Integrated-Conductor-Sensor-ICs/ACS756. aspx |
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| Downwind Guru Joined: 09/09/2009 Location: AustraliaPosts: 2333 |
No opamp required for that allegro,the output can be connected directly the the picaxe ADC input, although some filtering is required for stable readings. Its best to use the unidirectional sensor as this will give far better resolution, because it will give around zero volts out for zero current and 5 volts out for max current. The bidirectional sensors read plus and minus amps (which is often not required) and for zero current they output 2.5 volts, with zero volts out for max minus amps and 5 volts out for max plus amps. Have you seen this page on the forum. http://www.thebackshed.com/Windmill/articles/Alegro.asp Pete. Sometimes it just works |
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| scnarine Newbie Joined: 17/06/2011 Location: United StatesPosts: 29 |
Would I need to add the offset software: AmpOffset = 2.5 AmpReading = pin(1) - AmpOffset if AmpReading > -0.2 and AmpOffset < 0.2 then AmpOffset = 0 or AmpOffset = pin(2) - 2.5 AmpReading = pin(1) - AmpOffset if AmpReading > -0.1 and AmpOffset < 0.1 then AmpOffset = 0 If I need to add one of the above code where should I put it in the code? I did connect the allegro ACS756 and I zero the amp setting and it looks great to me. The whole project coming along great so far.....slow but sure, since I started this a few years ago... lol. I got a few BEFW11S4 linksys router for $1.00 each and I am using that as the project case. The LCD fits perfect in the front. I have a friend of mine who is a graphic designer is working on the front panel design. |
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