Differences

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--- seqv4plus_le_mec [2017/09/13 06:06]
latigid_on [BOM v1.0]
+++ seqv4plus_le_mec [2018/12/18 09:35] (current)
latigid_on [BOM v1.0]
@@ Line 1: / Line 1: @@
-====== SEQv4+ le MEC ======
+====== SEQv4+ le mec ======
 This board holds the SEQ's illuminated buttons, which are driven from a shift register matrix. The [[seqv4plus_enc-plate|ENC-PLATE]] board stacks on top.
@@ Line 6: / Line 6: @@
 ===== Schematic =====
-A shift register chain of 3 DIN 74HC165 and 2 DOUT 74HC595 chips are used. Two of the DINs scan the encoders and one scans the button columns. The DOUT parts are connected into a matrix. Note that both the high and low sides have driver transistors (PNP and NPN, respectively). This means that the anode side of the matrix will operate with inverted behaviour (pin high = LED off).
+A shift register chain of 3 DIN 74HC165 and 2 DOUT 74HC595 chips are used. Two of the DINs scan the encoders and one scans the button columns. The DOUT parts are connected into a matrix. Note that both the high and low sides have driver transistors (PNP and NPN, respectively). This means that the anode side of the matrix will operate with inverted behaviour (pin high = LED off). Actually the low (cathode) side is also "inverted," as we turn the transistor "on" to sink the current by toggling the 595 pin high.
 There are special instructions for connecting the parts which are covered below.
@@ Line 12: / Line 12: @@
 ===== BOM v1.0 =====
+**Please find the current BOM on [[http://midiphy.com]]. The table below is depreciated and will not be updated.**
 ^Type     ^Qty	^Value	   ^Package	^Parts^Mouser^Reichelt^Conrad^Other^Notes^
 ^Resistors^^^^^^^^^^
 |         |1    |wire link     |THT |R17   |      |        |      |     | |
-|         |18   |47R 5%        |THT    |RJ1-9  |  |        |      |     |see instructions |
+|         |16   |47R 5%        |THT    |RJ1-8  |  |        |      |     |see instructions |
-|         |8    |100-220R 5%   |THT or 1206 |SJ1-8  |      |        |      |     |see instructions |
+|         |10   |100-220R 5%   |THT or 1206 |SJ1-8, RJ9    |      |        |      |     |see instructions |
 |         |16   |1k 5%         |THT |R1-16  |      |        |      |     | |
+|         |8    |10k 5%         |1206 |R18-25  |      |        |      |     |near NPN transistors |
 ^Resistor networks^^^^^^^^^^
-|         |3    |9*10k   |SIP10 |RN1-3  |      |        |      |     |bussed, __not__ 5 pairs of resistors |
+|         |3    |9*10k   |SIP10 |RN1-3  |      |        |      |     |bussed network, __not__ 5 pairs of resistors |
 ^Capacitors^^^^^^^^^^
 |         |5    |100n   |1206 |C1-5 |     |        |      |     | |
@@ Line 26: / Line 30: @@
 ^Diodes^^^^^^^^^^
 |         |24    |1N4148 |THT         |            |      |        |      |     | |
+|         |24    |BAT54|SOT-23 |            |512-BAT54      |BAT 54 SMD        |      |     | |
 ^LEDs^^^^^^^^^^
 |         |16 |RGB flat |superflux  |            |      |        |      |ELV: 68-10 94 64     |see instructions|
@@ Line 44: / Line 49: @@
 ^Hardware^^^^^^^^^^
 |         |16   |switchcaps |ALPS-DSA clear  |             |        |      |     | | |
-|         |8    |switchcaps |22.5mm       | |642-1S11-19.0        |      |1S11-19.0     | | |
+|         |8    |switchcaps |19mm       | |642-1S11-19.0        |      |1S11-19.0     | | |
 **note that __two__ sets are required per SEQv4+ build!**
@@ Line 51: / Line 56: @@
 v1.0: first release.
+===== Errata =====
+==== v1.0 ====
+The C3 cathode row is missing a PCB trace. Join the two legs of SW19 as shown in pink, preferably on the bottom of the PCB. The LED cathode leg could simply be bent across to the switch pin.
+{{:seqv4plus:sinkbridge.png?nolink&800|}}
+Ghosting. As seems common with these kinds of matrices, there is some unwanted lighting of LEDs. This is most apparent when trying to light up the bottom row of MEC switch LEDs, as the resistive path to the Superflux LED is lower and thus glows unintentionally. This can be overcome somewhat by stacking BAT54 Schottky diodes on top of the BC818 transistors. Later revisions will have more elegant mounting.
 ===== Assembly =====
@@ Line 91: / Line 110: @@
   * THT resistors R1-16
     * take special care with R2, R3, R13 and R14 that the legs are as short as possible (even top-solder them). The encoder legs from the PCB stacked above will come down here.
-  * pin headers (top side)
+  * resistor networks. It's very important to have the pin 1 dot aligned with the silkscreen marking.
-  * resistor networks (bottom side). It's very important to have the pin 1 dot aligned with the silkscreen marking
+==== RJs ====
+The LEDs are available in RGB, but the official MIDIbox SEQ software only supports two of these colours. (if wanted, you could attach 0.1" headers to the PCB and drive the LEDs with custom hardware.) So we need to select what LEDs are in the matrix using the resistor jumpers (RJ). Find RJ1-8 spanning across the middle of the board. Pins A(1-8) and B(1-8) represent the 8 anode busses and pins 1, 2 and 3 represent the pins of the LEDs in the row.
+  * For the ELV-sourced LEDs, pin 1 as marked on the PCB is the red LED and pin 2 is the green one. You can mix the LED colours, e.g. if you wanted to show step 1 (and 9) as a different colour.
+  * For the Mouser-sourced LEDs, the pinout is different. You can always check the colours of LEDs by using the diode tester of your multimeter.
+  * Say we want red and green LEDs throughout. Simply solder RJ1-8 with 47R from A to 1 and B to 2 for each instance. RJ9 should match RJ1. For blue and green, solder A to 2 and B to 3 (depending on the LED used).
+  * Pinheader J4 is a vestigial connector and could be used for two extra LED functions.
+RJ9 connects to the [[seqv4plus_beat_led|Beat LED]] and so 100-220R resistors should be used here.
+==== SJs ====
+  * SJs are similar. As the current is quite high to drive the RGB LEDs, it's wise to use a 100-220R resistor to provide suitable current to the MEC LEDs.
+  * The position should match 1, 2 or 3 (two arbitrary positions) according to how the RJ of the same column is connected.
+  * Note that the forward voltage of the MEC switch LED should be the same as the position chosen on the RGB LED.
+  * For instance, if RJ was set to "3" (blue LED) and a red LED was used in a MEC switch, then the current path may illuminate the red one over the blue.
+==== Headers ====
+Continue on with the header pins. J5 should be connected to the [[seqv4plus_beat_led|Beat LED]] PCB; this needs some more thought. Header J14 can be used as a +5V supply. 1*10 Headers J1-3 can be installed, but best in conjunction with the [[seqv4plus_enc-plate|ENC-PLATE]] PCB to ensure correct alignment.
+Here is a good point to test out the BLM function. Some MB_NG app? With the Plate PCB to test out the DIN side?
+==== Switches ====
+Notice that the switches have not yet been soldered in. It should be alright to put in the MEC switches, as long as the LEDs have been inserted first! Like the [[seqv4plus_jog|Jog module]], the switches must be installed with the LEDs polarised correctly. The clearance with the Plate PCB is tight, so keep them straight.
+Note the LED polarisation:
+{{:seqv4plus:mec.png?nolink&400|}}
+//Very important//: the Matias switches must go in __through the completed Plate PCB!__ If they are put in before the Plate PCB, the **Plate PCB won't fit and there will be no way to mount the encoders!**
+Once the Matias switches are in, this should basically be the final step of le MEC.

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