tag:blogger.com,1999:blog-635269378459701716.post1063875730769352874..comments2023-11-16T00:18:17.221-08:00Comments on 1337 beef: Implementing Artcfox's TLC5940 code on an Arduino, Part 3Sweetlilmrehttp://www.blogger.com/profile/09298203937508653769noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-635269378459701716.post-48975325495308921292012-12-23T21:46:44.031-08:002012-12-23T21:46:44.031-08:00Peter, you wili be sent a photo this week. thanks ...Peter, you wili be sent a photo this week. thanks for the clarification on what chapter 9 is. I looked at the schematics and have a few comments about the selection of transistors and a few other details on the multiplexing.<br />It looks like the transistore were selected based on a convenient package to breadboard but not so much on a good fit for the string voltages and currents supported by the tlc.<br /><br />I believe you will do much better selecting a different device for your application. What is the maximum forward string voltage you are runing?<br /><br /> photon144https://www.blogger.com/profile/02493624603765453566noreply@blogger.comtag:blogger.com,1999:blog-635269378459701716.post-38979552873878720382012-12-22T23:17:44.067-08:002012-12-22T23:17:44.067-08:00Hi,
The transistors seem to be used as 'line&...Hi,<br /><br />The transistors seem to be used as 'line' switches for each colour.<br />If you look at the 'multiplexing.pdf' file in the schematics from Matt's site you will see that three transistors are used, one for each colour. Their switching is controlled by the AtMega.<br /><br />IIRC, CH9 is code only, Matt has not actually written it yet.<br /><br />I don't understand why you are getting such a low power output.<br />Can you take a picture of your wiring / setup and send it to sweetlilme(at)gmail(dot)com? Maybe I can find your issue that way?<br /><br />Have a great holiday!Sweetlilmrehttps://www.blogger.com/profile/09298203937508653769noreply@blogger.comtag:blogger.com,1999:blog-635269378459701716.post-53280625472195947462012-12-22T20:06:54.779-08:002012-12-22T20:06:54.779-08:00Mr. Edwards, thanks for pushing forwards on this. ...Mr. Edwards, thanks for pushing forwards on this. I have been busy as well but would like to take a bit more time over the holidays to follow up with you on all this. I have not read ch9 and wondering how the transistors are arranged. Is this to drive higher powered emitters?<br /><br />Went ahead and replaced the tlc chip described to you in the last email. Still cant figure out why the board is not providing a full 20mA of current to the leds. <br /><br />Still strange that the sense resistor is set at 2.2k and the 8 bit current and grey scale adjustments are set at full value..... still only getting a fraction of the total current out.... but otherwise everything seems to work correctly. It dims and the dot correction works.... Hmmmm <br /><br />I will go ahead and read more about the transistor applications and multiplexing (where does one find chapter 9?)<br /><br />happy holidays Photon144<br /><br /> <br />photon144https://www.blogger.com/profile/02493624603765453566noreply@blogger.com