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Messages - sam

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Development / Re: Flashing new code to the atmega
« on: March 29, 2016, 11:28:24 AM »
The ATMEGA chip included with the MIDI Sprout is a ATMEGA328-PU, rather than the 'low power' ATMEGA328p which is included in an Arduino Uno.

The updates i suggest to the avrdude.conf file are the easiest way that I have found to get the code compiled and loaded successfully on this 328 chip with the different signature.

The sync issue you are getting is due to the bootloader, the Arduino boot loader is not installed on the MIDI Sprout and will need to be flashed in order to use the Uno board as a programmer.

Using an Arduino as ISP, you should be able to program the MIDI Sprout using the ICSP on-board.  I used a USB-Tiny programmer when loading the boards.

I had hoped to make reprogramming the Sprout as easy as possible, but it does seem that the differences in chips requires some additional programming knowledge and steps.  I'll try to build an avrdude configuration and board file to match the Sprout.

Here are some online resources for using the 328-PU with the Arduino IDE:


Questions / Setup and Usage of MIDI Sprout
« on: March 29, 2016, 09:14:26 AM »
Add a Topic under this category to ask questions about MIDI Sprout setup and usage.

Click on the thread below to discuss your MIDI Sprout Setup and ask any Usage Questions:

Development / Re: Who's going to make a run of PCB's and enclosures?
« on: March 28, 2016, 10:30:43 PM »
You raise a great point.  If there is an interest in a group purchase, I also am looking to get a few boards.  Using OSHpark.com has been a great experience for me (and i highly recommend them for developers and hobbyists)

Let me try to figure out how to do a 'poll' asking "how many boards do you want" and we can see the response over the next couple weeks.  I can imagine that Kit users may want a board (and a cardboard enclosure) for their Sprout.  I'll make a Tutorial video on soldering to the MIDI Sprout circuit board from the kit parts (only missing part is the switch!)

Of course, the best part of open source is that you can roll your own boards 'now' on a cnc, perhaps photo transfer, or right through OSHpark:

Kit Instructions / Re: MIDIsprout Kit Build Discussion
« on: March 28, 2016, 10:17:08 PM »
The best way to determine the LED color is to use a CR2032 'watch'/button battery which can help to identify LED polarity and color.

When building the kits, all LEDs will eventually be illuminated, and the user can 'switch' LED locations to their taste once the kit is built.

In the Instructions you are right the same image is used in Steps 31 and 32.  The 'green' LED goes on the left side of the board between Row 12 and Ground.

Please find below, three videos detailing the assembly of the MIDI Sprout Kit:
1. MIDI Sprout Kit Parts (Part 1) -

2. MIDI Sprout Kit Galvanometer (Part 2) -

3. MIDI Sprout Kit Final Build (Part 3) -

Development / MIDI Sprout Development Discussion
« on: March 27, 2016, 05:13:33 PM »
Use this thread to discuss MIDI Sprout Development and ask questions.

Development / MIDI Sprout Circuit Board
« on: March 27, 2016, 05:12:21 PM »
Please find below links to eagle files of the MIDI Sprout circuit board, and a PDF of all the board layers.

Board Top PDF
Board Bottom PDF
Eagle Board File
Eagle Schematic File
Easy Schematic PDF
Gerber Zip

There are many great options for having a custom circuit board created.  I recommend using http://OSHpark.com who rapidly produce custom boards of 'any' size at a very affordable price.

The MIDI Sprout circuit board accommodates both SMD (surface mount) and Through-Hole components, making it easy for builders of many experience levels to construct the MIDI Sprout.
This is a link to my shared board design on OSHpark

Stay tuned to the http://support.midisprout.com/index.php?board=4.0 Tutorials section of the form for information about assembling a solder circuit board for the MIDI Sprout.

Development / Re: MIDI Sprout Code
« on: March 27, 2016, 04:45:58 PM »
The MIDI Sprout uses an ATMEGA 328-PU microprocessor, this is slightly different from the 328p which is found in most Arduino Uno boards.

When re-programming the MIDI Sprout, you can compile the code as an Uno but you will need to temporarily 'modify' the avrdude.conf file in order for the correct signature to be read from the chip.

The signature for non-P series 328 chips = 0x1e 0x95 0x14
The signature for 328"P" series used in the Uno = 0x1e 0x95 0x0F

One way to quickly program a non-P series chip is to update the signature in the avrdude.conf file.  Locate your Arduino IDE using Finder (under OS X), right click and choose Show Package Contents.
For example, this is the location of my avrdude.conf file: /Applications/Arduino_1.0.5.app/Contents/Resources/Java/hardware/tools/avr/etc/avrdude.conf

Open the avrdude.conf file in a text editor and search for the excerpt block of code below for the ATmega328P.

Code: [Select]
# ATmega328P

    id = "m328p";
    desc = "ATMEGA328P";
    has_debugwire = yes;
    flash_instr = 0xB6, 0x01, 0x11;
    eeprom_instr = 0xBD, 0xF2, 0xBD, 0xE1, 0xBB, 0xCF, 0xB4, 0x00,
  0xBE, 0x01, 0xB6, 0x01, 0xBC, 0x00, 0xBB, 0xBF,
  0x99, 0xF9, 0xBB, 0xAF;
    stk500_devcode = 0x86;
    # avr910_devcode = 0x;
#    signature = 0x1e 0x95 0x0F;
    signature = 0x1e 0x95 0x14;
    pagel = 0xd7;
    bs2 = 0xc2;

You can see that there are two signature lines in the example, one is 'commented' out using a # symbol. 

In order to program the MIDI Sprout, you will need to use the 0x14 signature, change your signature lines to match the code above, and save the avrdude.conf file. 

Recompile your program and upload, this should avoid the 'incorrect signature' error message.

Be sure to go back and change the commented signature line back to the 0x0F value in order for 'normal' compiling on your Uno.

Alternatively you can add a new Chip definition for the ATMEGA328-PU (non-P series) to the config file, and create a new entry in the boards.txt for selection in the Arduino IDE.   There are many resources online describing how to 'make' your own board definitions and how to connect to chips in the avrdude.conf file.

MIDI Sprout Tutorials / MIDI Sprout Tutorial - iOS Connection
« on: March 27, 2016, 04:24:14 PM »

You can connect your MIDI Sprout to an iPhone or iPad using a MIDI to iOS converter.  MIDI is 'plug and play' on most iOS Synths, and different iOS Synthesizer applications store their MIDI settings in varying locations; See the documentation from your favorite iOS Synth in order to locate and configure your MIDI inputs.

MIDI Sprout Tutorials / MIDI Sprout Tutorial - MIDI Sprout Tools
« on: March 26, 2016, 04:16:12 PM »

I am happy to release MIDI Sprout Tools v003 for PureData (pd)

This is an OSX puredata (PD) standalone build.  MIDI Sprout Tools v003

You will need to configure your MIDI inputs and outputs under Preferences. 

X11 is also needed to run pd extended on OS x.

Be careful, its really easy to get a feedback loop between Ableton Live and the IAC MIDI bus!


sNoize MIDI Monitor for OS X: https://www.snoize.com/MIDIMonitor/
MIDI-OX Monitor and Routing: http://www.midiox.com/

MIDI Sprout Tutorials / MIDI Sprout Tutorial - Batteries
« on: March 26, 2016, 04:15:17 PM »

1. Open the MIDI Sprout enclosure
2. Insert 3 AA Batteries - ensure correct polarity
   * MIDI Sprout does not have reverse voltage protection, inserting batteries in the wrong direction will cause the chips and wires to heat up (fast) and can destroy the MIDI Sprout
   * Battery connectors to circuit board - Positive (red) closer to Knob (blue component)
3. Close box and replace MIDI port retaining tab
4. Turn the knob clockwise to turn on, performing a brief boot up light show.

Low Power Mode experiments http://support.midisprout.com/index.php?topic=6.msg6#msg6

MIDI Sprout Tutorials / MIDI Sprout Tutorial - Welcome
« on: March 26, 2016, 04:14:38 PM »

Hello and Welcome to MIDI Sprout, your personal Biodata Sonification System!

Development / Secrets and Easter Eggs
« on: March 17, 2016, 08:47:44 PM »
As an Experimental Easter Egg... I have included a PWM to CV low pass filter on one of the ATMEGA328 outputs, this provides ~0-~5V control voltage which mirrors the CC 80 MIDI control.  By opening your Sprout and looking near the ICSP, you will see a pad marked CV. By tapping this point as positive voltage, and gathering Ground from another point on the board (there is a pad marked) you can easily break out the CV.

It is important to note, tying the MIDI Sprout ground to a modular synth may impact the 'sensitivity' of the device, depending on grounding loops and isolation.  One of the reasons the Sprout uses MIDI is to optically isolate the galvanometer attached to the plant from a user's synthesizer or computer (just like MIDI spec intended ;)

Please join our Support forum and share your experiences with adding the Control Voltage output (and whether it works or not!)

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