Differences

This shows you the differences between two versions of the page.

--- mididocs:seq:blm16x16_build_guide [2016/03/28 21:35] – [Parts list] latigid_on
+++ mididocs:seq:blm16x16_build_guide [2017/11/24 19:52] (current) – [Dimensions] latigid_on
@@ Line 25: / Line 25: @@
   * Pull-down resistors on current sink transistor bases (important when bases are floating and should decrease power consumption).
   * Schottky diodes from base to collector of current sink transistors. This helps to turn transistors "off" quicker and reduces "ghosting" in the matrix.
-  * Output enable (/OE) delay implemented on pin 6 of 74HC595 chips. At power up the capacitor will charge, holding all outputs in a high impedance state until the +5V rail is stable. At power down this capacitor discharges through a pull down resistor, aided by a diode. One delay circuit is provided for each SCALAR section.
+  * Output enable (/OE) delay implemented on pin 13 of 74HC595 chips. At power up the series capacitor will charge, holding all outputs in a high impedance state to ensure all registers have been initialised. One delay circuit is provided for each SCALAR section.
 For minimal external cabling, the BLM connects to a SEQ v4 via an 8-pin DIN connector. This combines MIDI in, MIDI out and power; the communications protocol sent and received by the BLM is standard MIDI. Most users will incorporate a Quad IIC board into their SEQ case, which is the simplest way to arrange the DIN8 connector, optocoupler and header pins.
@@ Line 113: / Line 113: @@
-  * You can choose whether you go for Blue+Green LEDs (recommended) or Blue+Red. You could interchange some Green for Red. Green+Red is not recommended as the colour mixing is poor.
+  * You can choose either Blue+Green LEDs (recommended) or Blue+Red. You could interchange some Green for Red. Green+Red is not recommended as the colour mixing is poor.
-  * Slider height: I specified 15mm shaft sliders, you could change these for 10mm. 15mm will protrude 13mm out of the case, which might be a bit long. 10mm will only protrude 8mm, so they would be less likely to break off and will probably be a bit more sturdy. TK. suggests 1k should work, the others are too high in resistance to get good jitter-free values (10k sliders with the shorter shaft don't appear to be available).
+  * Slider height: I specified 15mm shaft sliders, you could change these for 10mm. 15mm will protrude 13mm out of the case, which might be a bit long. 10mm will only protrude 8mm, so they would be less likely to break off and will probably be a bit more sturdy. TK. suggests 1k should work, the others are too high in resistance to get good jitter-free values (10k sliders with the shorter shaft aren't readily available).
   * You should use the indicated panel mount DIN, but a cheaper pair of DIN8 plugs might work.
   * M2 hardware is a bit difficult to find in normal stores, but Boltbase on eBay has good deals.
@@ Line 123: / Line 123: @@
   * Soldering iron, I managed with a normal tip but it’s a bit tricky with some components
-  * Solder, probably leaded. 0.5mm will make the finer pitch stuff easier but again I managed with 1mm
+  * Solder, probably leaded. 0.5mm is strongly recommended for at least the ICs (1206 can be easily done with 1mm solder).
   * Desoldering wick and/or solder pump. Useful when the pads get too much solder
   * Tweezers to pick and place components
@@ Line 131: / Line 131: @@
   * Flat work surface
   * Multimeter, test continuity between pads
+==== Dimensions ====
+Here are the dimensions for the button, hole and slider locations. Note that the unmarked mounting holes are M3 (3.2mm diameter)
+{{:blm16x16_x:dimensions.png?300|}}
+{{:blm16x16_x:dimensions.png?linkonly|}}