# The "Cheap Step Pro" **URL:** \ **Category:** DIY STUFF\ **Created:** [May 2, 2020, 5:29pm UTC](https://lookmumnocomputer.discourse.group/t/the-cheap-step-pro/792 "2020-05-02T17:29:22Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![twinturbo](https://avatars.discourse-cdn.com/v4/letter/t/8baadc/32.png) [@twinturbo](https://lookmumnocomputer.discourse.group/u/twinturbo)\ **Post date:** [May 28, 2020, 5:30am UTC](https://lookmumnocomputer.discourse.group/t/the-cheap-step-pro/792/41 "2020-05-28T05:30:59Z")
It’s not going to be cheap mind ☹ a rough rough ) BOM somehow comes to £100. If I lost he analog input it would probably save ~£30, but would probably replace with manual triggers which would bring it right back up. With the current dimensions it will be 375mm wide. It’s time to stop revising the high level design, test with the old V1 board that it does something ( in principal) check, check and tripple check, and correct… ---
**Author:** ![twinturbo](https://avatars.discourse-cdn.com/v4/letter/t/8baadc/32.png) [@twinturbo](https://lookmumnocomputer.discourse.group/u/twinturbo)\ **Post date:** [May 30, 2020, 4:24pm UTC](https://lookmumnocomputer.discourse.group/t/the-cheap-step-pro/792/42 "2020-05-30T16:24:44Z")
well after a number of issues with my 74151-754051 conversion (unexpected shorts when assembeld), blowing my PSU and other maladies. I finaly got the master to sequence a set of LED’s on the output pin header. So the output theory is sound even if the execution is a little haphazard. Waiting on some 20Pin cables so I can connect to the control board. ---
**Author:** ![twinturbo](https://avatars.discourse-cdn.com/v4/letter/t/8baadc/32.png) [@twinturbo](https://lookmumnocomputer.discourse.group/u/twinturbo)\ **Post date:** [May 30, 2020, 5:03pm UTC](https://lookmumnocomputer.discourse.group/t/the-cheap-step-pro/792/43 "2020-05-30T17:03:56Z")
![image](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/5/50873081dfe2c589ca0fd5e1f10d13e22b31801e.png) Those +6v rails have gone walkies!! ---
**Author:** ![lookmumnocomputer](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/lookmumnocomputer/32/23_2.png) [@lookmumnocomputer](https://lookmumnocomputer.discourse.group/u/lookmumnocomputer)\ **Post date:** [May 30, 2020, 5:29pm UTC](https://lookmumnocomputer.discourse.group/t/the-cheap-step-pro/792/44 "2020-05-30T17:29:38Z")
excited to see how this comes along! ---
**Author:** ![twinturbo](https://avatars.discourse-cdn.com/v4/letter/t/8baadc/32.png) [@twinturbo](https://lookmumnocomputer.discourse.group/u/twinturbo)\ **Post date:** [May 30, 2020, 5:47pm UTC](https://lookmumnocomputer.discourse.group/t/the-cheap-step-pro/792/45 "2020-05-30T17:47:54Z")
Yeah, it’s getting there. Will be ready to test the two main components together later in the week. Did a second sequence mux fix and that works although I think some of my leds have come adrift and the pin assignment is wrong at present. ![DSC_7693](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/5/562924b370dea2ac091e8423eaed713b2e26ad60.jpeg) ![DSC_7695](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/4/42f22cb21ca08a1caf8bcc24d96a57e905d2d1f7.jpeg) ![DSC_7696](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/8/8de5639987ae053a8f5bfed1c27d5c5f935b1b74.jpeg) ![DSC_7698](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/5/542d297308a3fb7311e42562b0501940a6363852.jpeg) ![DSC_7699](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/9/9111afecf962eed989f68fc4712e37976fe073d6.jpeg) ![DSC_7698](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/5/542d297308a3fb7311e42562b0501940a6363852.jpeg) [![](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/7/72ddcedfbe0c9381873f34b09de49af5a0b9ce80.jpeg "Cheap Step Pro, Bodged V1 board mux test.") ](https://www.youtube.com/watch?v=i6wlFhg9MMI) It’s not pretty, but it works. I have bridged the duino 5V to the 6V for the CV so I don’t have to use the PSU. ---
**Author:** ![twinturbo](https://avatars.discourse-cdn.com/v4/letter/t/8baadc/32.png) [@twinturbo](https://lookmumnocomputer.discourse.group/u/twinturbo)\ **Post date:** [June 5, 2020, 6:50pm UTC](https://lookmumnocomputer.discourse.group/t/the-cheap-step-pro/792/46 "2020-06-05T18:50:21Z")
Tested my control board (INPUT)… One failed LED for some obscure reason, I think these blue ones may be from a very cheap factory as I seem to have had a couple fail… Took a few mins to get the sequence right as the old V1 Brain and V1 Control dont match PIN for PIn… [![](https://global.discourse-cdn.com/free1/uploads/lookmumnocomputer/original/2X/f/f75f6d84abcef152953056f0f23f2653175ad105.jpeg "Cheap Step Pro control board. 1st test.") ](https://www.youtube.com/watch?v=uwWkZHeHBuM) Will hook up a Jack to the CV tomorrow and see if it actualy works… Pressing on whith ordering the new brain, sub boards and front panel … 🙂 ---
**Author:** ![CTorp](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/ctorp/32/15023_2.png) [@CTorp](https://lookmumnocomputer.discourse.group/u/CTorp)\ **Post date:** [June 5, 2020, 11:13pm UTC](https://lookmumnocomputer.discourse.group/t/the-cheap-step-pro/792/47 "2020-06-05T23:13:54Z")
Are you gonna sell me a board when you get it done? 😁 This looks great ---
**Author:** ![twinturbo](https://avatars.discourse-cdn.com/v4/letter/t/8baadc/32.png) [@twinturbo](https://lookmumnocomputer.discourse.group/u/twinturbo)\ **Post date:** [June 6, 2020, 6:10am UTC](https://lookmumnocomputer.discourse.group/t/the-cheap-step-pro/792/48 "2020-06-06T06:10:39Z")
will sort something, the bigest problem is that every sequencer requires 1 brain and 4 controls. So for every 5 Brains ordered from JLC, I need to order 20 Controls. although I have 5 useable control boards (minus the sub board)… never ordered more than 5 Prototypes… I don’t think it’s a cheap build. but as a multifunction compact 32/2x16/4x8 sequencer in a small space I think it will be useful to some. I have removed the diodes from the MUX as they are not needed, they were there to accomodate a Performance Button Module, but that can be added “In-Line” at a later date… I will test the CV output today, look over the schematics, tidy up and hopefully get the final PCB design orderd over the weekend. So in a couple of weeks should have the core hardware all done. I have just got to try and remember some of the code I deas that floated through my head and did not hit paper. Thanks Rob ---
**Author:** ![twinturbo](https://avatars.discourse-cdn.com/v4/letter/t/8baadc/32.png) [@twinturbo](https://lookmumnocomputer.discourse.group/u/twinturbo)\ **Post date:** [June 6, 2020, 1:18pm UTC](https://lookmumnocomputer.discourse.group/t/the-cheap-step-pro/792/49 "2020-06-06T13:18:53Z")
spent ~6hrs this morning ( must be near 100Hrs now ) doing the control front panel, correcting a few minor things on the schematics and PCB’s Realised a clearence issue on the old control board and it’s SUB jack board, wont affect future boards but I will have to do a bit of filing on my present ones. Pushed the new SUB Jack, New Brain, Control PCB to print… Yikes… Only bits missing now are the Brain Panel, and a Performance Button Module ( PCB and Front Panel ) the latter are an easy additional module. Will be glad to get this finished, there’s other projects backing up in my head not just for Synth but for Stage Lighting… ---
**Author:** ![TrapaNatans](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/trapanatans/32/9318_2.png) [@TrapaNatans](https://lookmumnocomputer.discourse.group/u/TrapaNatans)\ **Post date:** [June 6, 2020, 7:12pm UTC](https://lookmumnocomputer.discourse.group/t/the-cheap-step-pro/792/50 "2020-06-06T19:12:03Z")
blue LEDs are the most vulnerable anyway ---
**Author:** ![TrapaNatans](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/trapanatans/32/9318_2.png) [@TrapaNatans](https://lookmumnocomputer.discourse.group/u/TrapaNatans)\ **Post date:** [June 6, 2020, 8:02pm UTC](https://lookmumnocomputer.discourse.group/t/the-cheap-step-pro/792/51 "2020-06-06T20:02:22Z")
we all have too many projects here, haven’t we? What type of stage lighting? I built a 500W [Dream Machine](https://en.wikipedia.org/wiki/Dreamachine) we used it in our live concerts already. ---
**Author:** ![twinturbo](https://avatars.discourse-cdn.com/v4/letter/t/8baadc/32.png) [@twinturbo](https://lookmumnocomputer.discourse.group/u/twinturbo)\ **Post date:** [June 7, 2020, 7:39am UTC](https://lookmumnocomputer.discourse.group/t/the-cheap-step-pro/792/52 "2020-06-07T07:39:48Z")
Stage lighting, currently on the list… I am doing a DMX relay controller (it’s actually for a C02 Cannon) I have to re-engineer the drive electronics for a Showtec Phantom 250 Moving Head Wash… We build a Analog Desk to DMX interface for QLC+ but that needs rebuilding. Got car electronics projects on the go as well, engine management and power delivery. ---
**Author:** ![twinturbo](https://avatars.discourse-cdn.com/v4/letter/t/8baadc/32.png) [@twinturbo](https://lookmumnocomputer.discourse.group/u/twinturbo)\ **Post date:** [June 7, 2020, 9:17pm UTC](https://lookmumnocomputer.discourse.group/t/the-cheap-step-pro/792/53 "2020-06-07T21:17:47Z")
ahhh dam… just found these lovely little things > **[Mega 2560 PRO MINI, ATmega2560-16AU](https://robotdyn.com/mega-2560-pro-mini-atmega2560-16au.html)** > > The Mega Pro MINI CH340G / ATmega2560 board is based on the ATmega2560 microcontroller and the USB-UART adapter CH340. The board is compatible with Arduino Mega 2560. V3… ---
**Author:** ![twinturbo](https://avatars.discourse-cdn.com/v4/letter/t/8baadc/32.png) [@twinturbo](https://lookmumnocomputer.discourse.group/u/twinturbo)\ **Post date:** [June 9, 2020, 12:13pm UTC](https://lookmumnocomputer.discourse.group/t/the-cheap-step-pro/792/54 "2020-06-09T12:13:01Z")
Got stung again for my board split (I think) not sure why this time as it was electrically connected. Also got stung on Customs for 300 Potentiometers ☹ … Got my cheap knobs though yesterday, and 10 I2C displays… Rob ---
**Author:** ![sebastian](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/sebastian/32/39_2.png) [@sebastian](https://lookmumnocomputer.discourse.group/u/sebastian)\ **Post date:** [June 21, 2020, 7:38am UTC](https://lookmumnocomputer.discourse.group/t/the-cheap-step-pro/792/55 "2020-06-21T07:38:27Z")
What can the mega do that the Nano can not in this context? And how did you decide on the mux chips? I am planning something with 30 analog inputs and have no Good Plan how to approach this… ---
**Author:** ![Caustic](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/caustic/32/15588_2.png) [@Caustic](https://lookmumnocomputer.discourse.group/u/Caustic)\ **Post date:** [June 21, 2020, 7:44am UTC](https://lookmumnocomputer.discourse.group/t/the-cheap-step-pro/792/56 "2020-06-21T07:44:02Z")
So, even though i sat on mine and broke it, i learned a lot from the project. I just used the 74HC4051 8 channel multiplexer and a knockoff nano. Use as many multiplexers as you need, and use the “Control Surface” lib for arduino. I can help you with it if you want assistance. It’s really easy as cake. The next time around, im just going to give the sliders more space in-between and such. That library really makes everything super duper easy. If you want to know how to hook everything up i can help there too. Just keep in mind that the multiplexer chips should only be used for either digital or analog at any one time. They can be used for either, but it only works with one type at any one point. > [@DIY controllers](https://lookmumnocomputer.discourse.group/t/diy-controllers/57/26): > > Been dabbling with the “Control Surface” Lib for Arduino. Wow its easy to use. Ive only scratched the surface, but yeah its really good. Way better than the default midi lib. [https://tttapa.github.io/Control-Surface-doc/Doxygen/d5/d7d/md\_pages\_Getting-Started.html#first-input](https://tttapa.github.io/Control-Surface-doc/Doxygen/d5/d7d/md_pages_Getting-Started.html#first-input) Some demo serial out messages from the USBDebugMIDI\_Interface: 01:15:02.777 -\> Control Change Channel: 2 Data 1: 0x07 Data 2: 0x40 Cable: 0 01:15:02.812 -\> Control Change Channel: 2 Data 1: 0x… ---
**Author:** ![twinturbo](https://avatars.discourse-cdn.com/v4/letter/t/8baadc/32.png) [@twinturbo](https://lookmumnocomputer.discourse.group/u/twinturbo)\ **Post date:** [June 21, 2020, 8:03am UTC](https://lookmumnocomputer.discourse.group/t/the-cheap-step-pro/792/57 "2020-06-21T08:03:05Z")
Mega has significantly greater I/O capacity, as I am addressing 8 muxes with three address lines each it needs 32 I/O pins. It could be made more I/O efficient I suppose by muxing the adressing. I may consider that in the next version. I have the Mega Pro boards now and they are super cool. I thought about combining the addressing for the output and input, but I think I will be doing “read ahed”, so the input is read on the step befor the output. but perhaps that can be addressed by just changing the input order on the mux… food for thought… Been waiting on the V2 Brain, Control Panel and Daughter board for a couple of weeks. slow progress at present ---
**Author:** ![Caustic](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/caustic/32/15588_2.png) [@Caustic](https://lookmumnocomputer.discourse.group/u/Caustic)\ **Post date:** [June 21, 2020, 8:32am UTC](https://lookmumnocomputer.discourse.group/t/the-cheap-step-pro/792/58 "2020-06-21T08:32:35Z")
You know, you can just use one address bus for digital and one for analog (6 pins). That’s what the chip select signal is for! Just use code to dictate which mux you are talking to. Its as simple as just having s0, s1 and s2 pins on all of those mux hooked up together. ---
**Author:** ![Bitnik](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/bitnik/32/274_2.png) [@Bitnik](https://lookmumnocomputer.discourse.group/u/Bitnik)\ **Post date:** [June 21, 2020, 10:06am UTC](https://lookmumnocomputer.discourse.group/t/the-cheap-step-pro/792/59 "2020-06-21T10:06:33Z")
> [@Caustic](#): > > So, even though i sat on mine and broke it, i learned a lot from the project. Testing your modules to destruction. Such dedication! ---
**Author:** ![twinturbo](https://avatars.discourse-cdn.com/v4/letter/t/8baadc/32.png) [@twinturbo](https://lookmumnocomputer.discourse.group/u/twinturbo)\ **Post date:** [June 21, 2020, 10:17am UTC](https://lookmumnocomputer.discourse.group/t/the-cheap-step-pro/792/60 "2020-06-21T10:17:00Z")
yeah… I am sure i must have had a reason to do it the way i did, but not sure why. I think possibly to do with me thinking there is no latching… I will review the datasheet on the 4051. Cheers… [Previous page](https://lookmumnocomputer.discourse.group/t/the-cheap-step-pro/792.md?page=2) [Next page](https://lookmumnocomputer.discourse.group/t/the-cheap-step-pro/792.md?page=4)