project status: in progress
timeline:
- interest gathering / order number estimates [in progress]
- final driver PCB revision. [done, ordered]
- programming and test jig [done, ordered]
- driver PCB fabrication & assembly [to do]
- firmwares modifying & testing [to do]
- shopify / ordering system [to do]
- shipping [to do]
- 40h kit / Arduinome adapter PCB [done]
firmwares:
- original series [done]
- greyscale
- 40h
- other sub revisions?
- arduinome
4-level brightness grid upgrades - not possible with this hardware. may look into in the future.
original post:
hello
over the last year and a half (part time) i have developed a variable brightness upgrade for older monome grid devices. the upgrade is a soic sized max7219/7221 replacement, and a firmware upgrade for the monome grid logic board.
firmware for the original series grids is complete. all serial led functions.
grayscale and even 40h firmwares should also be doable.
an adapter board for kits and arduinomes using the dip package max7219/7221 can also be created, if there is interest.
the upgrade would require the following equipment:
-
soldering iron
- good temperature control
- 1 larger tip for desoldering
- 1 finer tip for soldering vb_driver
-
tweezers
-
multimeter
-
flux (tacky), noclean
-
isopropyl alcohol (or an ultrasonic cleaner)
-
something to scrub/wipe the alcohol with (old toothbrush, paper towels)
-
solder (lead free for keeping with monome standards)
-
atmel dfu programmer for upgrading the logic board
-
1 vb_driver per 8x8 monome grid.
- 64 = 1
- 128 = 2
- 256 = 4
- 512 = 8
these are the simplified steps to complete the upgrade:
-
disassembly
https://monome.org/docs/disassembly/
-
desolder the MAX7219
i used the following method:
https://www.youtube.com/watch?v=UmD7F0--7Lc&t=832s
-
clean / inspect
scrub the boards with isopropal alcohol to remove the sticky residue left behind from the flux. you may need to do this several times. alternatively use an ultrasonic cleaner. or any other appropriate method you find.
check the whole PCB for solder balls. using the above desoldering method theres a high chance small solder balls are formed and can end up just about anywhere on the PCB. i’ve had some bridge pins on the keypad multiplexers. this lead to (temporarily) dead rows / random button presses.
-
solder vb_driver
carefully align the vb_driver in place of the max7219 and in the correct orientation. you need to get this right first time. i’ve had extremely low success desoldering vb_driver without damaging the castellated vias on its sides.
solder/tack one of the castellated vias, check alignment, solder one on the opposite side, check alignment, then solder the rest.
-
clean / test / Inspect
clean again.
use the multimeter to test for continuity between adjacent connections on the driver. test that each connection has continuity to another connected part of the board. ie the ribbon cable connector
again inspect the PCB for solder balls.
-
upgrade the logic board firmware
Makefile for avrdude:
cd (firmware directory)
make pro
-
test
before putting everything back together its a good idea to connect everything up and run through some tests to ensure the driver, and the keypads are both working correctly.
-
reassemble
disassembly instructions in reverse
these instructions are rather brief and will be expanded on in time.
pricing:
to be confirmed, but likely around US$50 per vb_driver shipped from New Zealand.
i will most likely assemble these myself. if there is a massive amount of interest i may move to commercial fabrication. this may change the price.
if you’re interested, comment below, let me know what size grid(s) you would potentially order for.
i will use this information for estimating an initial run, which i will offer via shopify when built.
addtional:
this upgrade is somewhat complex, and not beginner friendly.
suggest practicing desoldering on something else (less important) before taking an iron to your grid if you’ve never done it before. or find someone in your area to do it… people could offer / request upgrade services here (or in another thread).
i will probably open source the hardware design and driver firmware at some point.
more info to come.