This is a great little unit. I switch custom SS Leslie speaker relays with it. Now I can't run my studio without it!

Wow !!
This things is brilliant.

The build instructions are EXCELLENT.
I’ve built a kit valve amp before so I had a reasonable idea what I was doing, but I can’t say just how good the instructions are. If you screw this up, you’d have to be pretty dumb.

It really needs the proper power supply to operate the relays.

I was hoping to use a USB phone power supply... NUH. Not enough current.
Got a 5v 500ma supply & it works straight away.

I’m using this to generate contact closure to trigger an RC50 (coz Roland omitted being able to trigger the phrases by midi)
Anyway, it worked straight away.
Couldn’t be happier.

Thanks chaps,

Does exactly what it says on the tin. Very easy to build, controls 8 relay switches via midi; I'm using it to control guitar amp channel switching, reverb, etc. but the applications are endless.

Got this last year and have only just put it together. Very easy build and clear and simple instructions on the net and configuration easy. Have been wanting to control physical objects from ableton and didn't find much on the net. This device opens up a world of possibilities for someone with basic knowledge of electronics. Great to see someone making products that large manufactures won't.

Thank you for the excellent midi to relay, shipping fast, low cost and efficient :-)
my Mesa Boogie Quad Preamp is now MIDI.......great
mathieu analogique

I'm going to buy more of these. too many uses to list. be safe if you use it with mains. works great. thanks hotchk155!

I purchased this product to reroute signals in my guitar processing rack. Using a Gordius Little Giant foot controller, I can change the state of any/all relays with a single footswitch press. This product is by far the most cost effective means of accomplishing the required task.

I encountered my only difficulty when trying to use the Little Giant to program the relay configuration in programming mode. The documentation presents the midi data for configuration in hex. After some experimentation, monitoring the output of the java app in Midiox, I was able to determine that the configuration data consists of simple control change commands that many midi controllers can send.

I assembled the following chart, and present it here in case it can be of help to others such as myself.

Set relay to respond on a specific MIDI channel
CC# Value Comments
99 0 to 7 Selects which port (relay) to configure. Value ranges from 0 (port a) to 7 (port h).
98 1 Value of 1 selects the channel number parameter as the one to be configured.
06 0 Value will always be zero when configuring the channel number parameter.
38 0 to 15 Sets the relay to channel (value + 1). Value ranges from 0 (ch 1) to 15 (ch 16).

Set relay to respond to a specific note number
CC# Value Comments
99 0 to 7 Selects which port (relay) to configure. Value ranges from 0 (port a) to 7 (port h).
98 2 Value of 2 selects the note number parameter as the one to be configured.
06 0 Value will always be zero when configuring the note number parameter.
38 0 to 127 Sets the note number to which the relay will respond. Refer to a midi note chart.

Set relay duration for note on/off configuration
CC# Value Comments
99 0 to 7 Selects which port (relay) to configure. Value ranges from 0 (port a) to 7 (port h).
98 3 Value of 3 selects the duration parameter as the one to be configured.
06 0 to 127 See below.
38 0 to 127 See below.
Both values will be zero to retain relay state until note off (or on) message is received. Non-zero values must be calculated. Perhaps someone can figure out and post a formula. I always use zero values in my application.

Set relay duty cycle
CC# Value Comments
99 0 to 7 Selects which port (relay) to configure. Value ranges from 0 (port a) to 7 (port h).
98 5 Value of 5 selects the duty cycle parameter as the one to be configured.
06 0 Value will always be zero when configuring the duty cycle parameter.
38 64 Value ranges from 0 (relay disabled) to 64 (100%) duty cycle.

Set relay to be non-inverted or inverted
CC# Value Comments
99 0 to 7 Selects which port (relay) to configure. Value ranges from 0 (port a) to 7 (port h).
98 7 Value of 7 selects the invert parameter as the one to be configured.
06 0 Value will always be zero when configuring the invert parameter.
38 0 or 1 Value can be 0 (non-inverted) or 1 (inverted).

Store configuration to EEPROM
CC# Value Comments
99 100 Value will always be 100.
98 1 Value will always be 1.
06 0 Value will always be 0.
38 1 Value will always be 1.


PS. The formatting was destroyed upon upload to this review board. The CC#, Value, and Comments columns were squashed together into one unreadable mass. Knowing these are three separate columns might make it easier to decipher the information in each section.

I assembled the kit today and all eight channels are working perfectly. I couldn't be more pleased with my purchase. Seller was easy to get ahold of and was happy to answer my questions.

The kit arrived in great condition, all parts were safely wrapped. Documentation was thorough and relatively easy to follow, even for someone with no previous experience like myself. The configuration app worked fine, but was a little tricky to figure out at first (be sure to read the instructions very carefully)

Thanks for the great product.

Fantistic little device and easy to ensemble. I use it to automate a VMS70 disc cutting lathe. Maybe the interface to program the IC could be improved and made easier to use but overall very happy with price/quality.