MIDIbox Hardware Platform, Digital OUT Module

The DOUT module comes with multiple serial registers 74HC595; every register provides 8 digital outputs, which are updated with the latch enable signal RCLK and shifted out with the clock signal SCLK. The advantage of using such shift registers is, that they can be cascaded to a long chain without the need of more than 5 cables to the core module. The DOUT board has been designed on a way which allows to cascade not only the ICs on the board, but also several DOUT modules. But note that it depends on the firmware how much outputs are processed by the core module. For instance, the MIDIbox64 allows to connect up to 64 LEDs = 8 ICs = 2 * DOUTX4, the MIDIO128 supports 128 outputs = 16 ICs = 4 DOUTX4 modules.

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Note: To reduce effort only the DOUTX4 variant is available at Mikes PCB shop. If you don't want to etch the modules by yourself, just use the DOUTX4 and stuff just only the ICs which are really required.

PCB data, can be viewed, modified and converted with Eagle Light Thanks to Marfurt Cyrill for layouting the DOUTX3, DOUTX2 and DOUT_MTC modules!
Module	Schematic	Layout Data	Quick-view
MBHP_DOUTX4_V1	mbhp_doutx4.pdf	mbhp_doutx4_v1.brd	mbhp_doutx4.gif
MBHP_DOUTX3_V1	mbhp_doutx3.pdf	mbhp_doutx3_v1.brd	mbhp_doutx3.gif
MBHP_DOUTX2_V1	mbhp_doutx2.pdf	mbhp_doutx2_v2.brd	mbhp_doutx2.gif
MBHP_DOUTX1_V2	mbhp_doutx1.pdf	(normaly built on veroboard)	(normaly built on veroboard)
MBHP_DOUT_MTC_V1	similar to DOUTX4	mbhp_dout_mtc_v1.brd	mbhp_dout_mtc.gif

Additional informations
File	Size	Description
mbhp_doutx4_orderlist.txt	1k	Reichelt orderlist
mbhp_doutx4_32leds.pdf	16k	How to connect 32 LEDs
mbhp_doutx4_ledrings.pdf	31k	How to connect 16 LED-rings to the MIDIbox16E
mbhp_doutx4_mtc.pdf	12k	How to connect 8 LED-digits for the MTC display of MIDImon
mbhp_doutx1_reed_relays.pdf	9k	How to connect Reed Relays to a DOUT module - see also this photo

Available Ports

Following interfaces are provided by the doutx4 module:

Name	No. of pins	Description
J1	5	Interface to CORE:J8 (if LEDs are used) and CORE:J7 (if LED-Rings are used, MIDIbox16E only). DOUTX4:J1 provides two power pins for 5V/0V, the serial clock, the latch enable and the serial input of the register chain. This port can also be connected with J2 of another DOUTX module.
J2	5	Interface to another DOUTX4 module. DOUTX4:J2 provides nearly the same pins like J1, just only the serial input of the first IC is replaced by the serial output of the last IC. This port can be connected with J1 of another DOUTX module.
J3-J6	5	These are the digital output lines, every connector comes with 8 of them and an additional pin for ground. See mbhp_doutx4_32leds.pdf as an example how to connect LEDs to these pins, and mbhp_doutx4_ledrings.pdf how to connect LED rings.

Used Components

Here a list of the used components. A complete orderlist for Reichelt can be found here, Mouser partlist for the US: see SmashTV's Website, if you have a orderlist for a distributor on your country, feel free publish it on this page!

Part Name	Value	Description
IC1, IC2, IC3, IC4	74HC595	The digital output shift registers
R1-R32	220	These resistors are required if LEDs should be driven with the output, just to limit the current through the LEDs. If you are using the DOUT module with a MIDIO128, and would like to drive additional logic chips instead of LEDs, these resistors are not required and can be replaced by bridges. If the module is used to drive the LED-Rings of MIDIbox16E, R1-R16 have to be replaced by bridges, see also mbhp_doutx4_ledrings.pdf
C1-C4	100nF	The additional bypass caps have to be placed on the bottom side of the PCB, as close to the +5V power input of the 74HC595 as possible.
J*	*	All connectors are optional, the cables can also be soldered directly into the board. Otherwise I suggest SIL headers (header sockets), known from PC motherboards. They are cheap and usefull.
DIL	SOCKETS	Don't forget to buy sockets for the shift registers. 4 * 16 pin DIL sockets are required.

Soldering Guide

	Start with soldering the 15 bridges which save you from creating a 2-layer board. You can use the cutted legs of caps and resistors, before you throw them away after you finished all the modules! :-) Note that the 5 bridges between Pin 13 of the ICs and Vss (ground) and Pin 15 -> J6:D0 will be soldered at the bottom side!
	Mount the IC-sockets before continuing.
	This picture shows the 5 additional bridges, realized with isolated cables.
	Add also the four additional Bypass Caps between Vdd and ground (Vss) of each chip on the bottom side of the PCB as close to the +5V power input of the 74HC595 as possible. Add an additional cap (100 uF) at the power input of the DOUT module. These caps improve the power integrity.
	A full stuffed DOUTX4 module within a MIDIbox64.
128 outputs for MIDIO128 (yes, this picture is a fake! ;-)

Last update: 2010-03-06