Totus Terra - Latest comments http://totusterra.com/index.php?disp=comments en-US hourly 1 2000-01-01T12:00+00:00 In response to: Using the 555 timer as an external clock for the Arduino http://totusterra.com/index.php/2009/10/31/using-the-555-timer-as-an-external-clock#c95 2010-04-22T15:27:32Z Heather [Visitor] I love the calculator - it's just what I needed! Thanks for sharing! In response to: Hacking the SX-150. Building an Arduino-based sequencer - Part 2 http://totusterra.com/index.php/2010/01/09/hacking-the-sx-150-building-an-arduino-b-2#c86 2010-04-11T08:03:10Z Rob [Visitor] Hi, <br /> Some time ago I interfaced an old Psion organiser to a Yamaha mono analogue synth to make a sequencer. I went down the D/A converter to control voltage route, and came up with the same limitations with an 8 bit output... The notes sometimes aren't quite accurate. The digital pot method is quite interesting. I imagine using an 8 bit output into a 10K digipot is quite accurate as the notes go (as you say over one octave), so if two of them were used, the 10K for note control using 7 bits, and say, another at 10K configured to be 'on' or 'off' to 'flip' the octave up or down 1 with the remaining bit (most likely the LSB), would it be possible to obtain better note accuracy over more octaves? If good note accuracy can be gained with 6 of the MSB's, then the remaining two LSB's could be used to switch four octaves.<br /> <br /> Anyhow, regarding the SX150 schematic. I am building my own, yet apart from the power connections to the 555 timer which are obvious, there are no other connection details for this device. This means there are six pins that I have no idea about, which is frustrating as I have used these IC's for three quarters of my life... Would anyone be willing to do a skill swap? I can design electronics and program in HEX etc... Maybe I can help in some way? I just need to know where the pins of the 555 go if someone can be bothered to trace them!<br /> <br /> Many thanks, <br /> <br /> Rob. Some time ago I interfaced an old Psion organiser to a Yamaha mono analogue synth to make a sequencer. I went down the D/A converter to control voltage route, and came up with the same limitations with an 8 bit output... The notes sometimes aren't quite accurate. The digital pot method is quite interesting. I imagine using an 8 bit output into a 10K digipot is quite accurate as the notes go (as you say over one octave), so if two of them were used, the 10K for note control using 7 bits, and say, another at 10K configured to be 'on' or 'off' to 'flip' the octave up or down 1 with the remaining bit (most likely the LSB), would it be possible to obtain better note accuracy over more octaves? If good note accuracy can be gained with 6 of the MSB's, then the remaining two LSB's could be used to switch four octaves.

Anyhow, regarding the SX150 schematic. I am building my own, yet apart from the power connections to the 555 timer which are obvious, there are no other connection details for this device. This means there are six pins that I have no idea about, which is frustrating as I have used these IC's for three quarters of my life... Would anyone be willing to do a skill swap? I can design electronics and program in HEX etc... Maybe I can help in some way? I just need to know where the pins of the 555 go if someone can be bothered to trace them!

Many thanks,

Rob.]]> In response to: Connecting a 7-segment LED to the Arduino http://totusterra.com/index.php/2009/09/07/connecting-a-7-segment-led-to-the-arduin#c66 2010-03-26T15:03:12Z Jeff [Member] Glad I could help :) In response to: Connecting a 7-segment LED to the Arduino http://totusterra.com/index.php/2009/09/07/connecting-a-7-segment-led-to-the-arduin#c63 2010-03-26T02:58:25Z sli [Visitor] You, my friend, just saved me a huge headache by posting the picture of the back of the package. I lost mine a while back and I've been tearing my hair out trying to figure out which pin is for what. In response to: Using the 555 timer as an external clock for the Arduino http://totusterra.com/index.php/2009/10/31/using-the-555-timer-as-an-external-clock#c46 2010-03-08T11:48:23Z Kerman [Visitor] I had not seen the attachInterrupt function in action before either and have been polling inputs on a loop In response to: Connecting a 7-segment LED to the Arduino http://totusterra.com/index.php/2009/09/07/connecting-a-7-segment-led-to-the-arduin#c31 2010-01-30T03:50:41Z James [Visitor] thanks for your concept of breadboarding a circuit, <br /> it will help me a lot. it will help me a lot.]]> In response to: Hacking the SX-150. Building an Arduino-based sequencer - Part 2 http://totusterra.com/index.php/2010/01/09/hacking-the-sx-150-building-an-arduino-b-2#c19 2010-01-11T16:27:59Z Jeff [Member] Thanks for the comment.<br /> <br /> That'd pretty trivial for the code part -- and if I wanted to play tunes from my arduino sketch that would be the way to go -- but for the step sequencer I have in mind (or if I wanted to hook up midi control to it, etc.) being able to reference the notes by numeric value is all I need, and timing is externally controlled. But if you want to take the code and do that with it, you're more than welcome to!<br /> <br /> Jeff
That'd pretty trivial for the code part -- and if I wanted to play tunes from my arduino sketch that would be the way to go -- but for the step sequencer I have in mind (or if I wanted to hook up midi control to it, etc.) being able to reference the notes by numeric value is all I need, and timing is externally controlled. But if you want to take the code and do that with it, you're more than welcome to!

Jeff]]> In response to: Hacking the SX-150. Building an Arduino-based sequencer - Part 2 http://totusterra.com/index.php/2010/01/09/hacking-the-sx-150-building-an-arduino-b-2#c18 2010-01-11T14:41:10Z KenN [Visitor] Very good. Now you need to add a double array of note<br /> values and lengths and you can play actual tunes values and lengths and you can play actual tunes]]>