Making the Roland DXY-1200 pen plotter wireless (bluetooth) for about 10€

Easy and cheap hack

My office is quite cluttered with hardware. I’ve been toying with chiplotle lately but doing so meant cleaning up my desk and make room for the big clunky 80ties plotter. Chiplotle just sends serial commands, so why not over bluetooth. I ordered a


HC06 serial bluetooth module widely available


and a


serial to ttl converter powered by USB


just hooked it up together with a DB9-DB25 convertor and it just worked… pairing the HC06 was with the code 1234, instead of OSXs default 0000. besides that, no problems.

I set my



serial_port_to_plotter_map = {‘/dev/tty.HC-06-DevB’ : ‘DXY-1300’}

and of we goplottersetup

The whole setup is usb powered and works really smooth. I can now leave the plotter at a convenient place in my office and play with it… wirelessly yay!





flashing the mi mini wifi router with OpenWRT

I lost connection with the mi mini wifi router after following this procedure. I flashed u-boot to the bootloader, and it succeeded, but It would no longer boot the firmware.
Apparently it did boot into u-boot, but to find that out I had to get a serial console. Instead of getting a usb serial to TTL I tried using a raspberry pi and the GPIOpins. It worked.

opening the MI mini wifi

two screws hold i together, opening it from there was a bit harder. You have to forcefully get underneathe four little hooks at the bottom front of the device

holes in the router

after opening it, all we need is accessible.

soldering a serial port on it

I used an old connector I had lying around, easy t get to the breadboard

nice solderpads, easy connection

next step involves the RPi

you can then hook it up to the RPis Tx, Rx and GND pins. As both devices use 3v3 TTL, no extra circuitry is needed

ssh over to the RPi

once your logged in, type

$ minicom -b 115200 -o -D /dev/ttyAMA0

to start a serial console on the RPis GPIOports. Once it runs, boot the mi and you should see this

Screen Shot 2015-06-09 at 20.46.36


now the easy part

connect a UTP cable from a LAN port directly to your computer, and assign your PC a manual address in th 192.168.1.x but not

start the http server on the mi

MT7620 # httpd
raspi_read: from:40028 len:6
NetTxPacket = 0x83FB5080

KSEG1ADDR(NetTxPacket) = 0xA3FB5080
Trying Eth0 (10/100-M)

Waitting for RX_DMA_BUSY status Start… done
HTTP server is starting at IP :
HTTP server is ready!

Keep going WEB failsafe, rx_counter=0 , GoGoGo!!!

point you browser to

and upload your firmware…

I flashed openwrt-ramips-mt7620-xiaomi-miwifi-mini-squashfs-sysupgrade.bin

connect to internet (cable)

and start setting up OpenWRT

$ opkg update && opkg list luci-*
$ opkg install luci-ssl

$ /etc/init.d/uhttpd start
$ /etc/init.d/uhttpd enable

$ uci set wireless.@wifi-device[0].disabled=0; uci commit wireless; wifi


make sure it boots from the flash partition

by default it waits for a tftp image to be transferred, so:

$ printenv

and take a look at the env variables

$ bootcmd=tftp

this should be

“bootcmd=bootm bc050000”

so set it and save it

$ setenv bootcmd bootm bc050000

$ saveenv

now reboot, test and go and configure it

OHM2013 moldover show

I was at OHM2013 for some hacking, meeting friends and meeting new people. One of them was @moldover and he brought his gear (mojo & robocaster)! As I’m building my own controller (for visuals and vegetables) I started talking to him. He was going to perform later that day at Rainbow Island. So I offered him a live VJset and after little to none preparation time I was able to fix my setup enough to get going. And so we did. And because it was fun, we did it again the next day. Inspired by the great place Rainbow Island is I gatherered some (retro) pixels during the day from dancing my little ponys to the masks from hotline miami. The people for rainbow Island added more beamers and splitters and lights and fire and the results was fun.

some pics

full video

Moldover full show 2-8-2013 @ Rainbow Stage - OHM2013 - YouTube


This is a big one. It’s a packet analyzing network sniffer that outputs crazy rhythms, mapped to crazy sounds. We (me and @0xtosh) set it up at HAR2009 were people could log in to a linux VM, run some scripts, ours or their own, to scan the network and netglitch broadcasted a shoutcast stream to which you could tune into to listen to your own packets.