Thursday, October 27, 2011

20000 Page Views

Last week I hit 20000 page views (more than I would have expected), I'm pretty surprised especially considering the very narrow scope of my posts.

Lots of interest from Russia and Poland on many of my projects; apparently I was born on the wrong continent.

Thanks Everyone / dziękuje wszystkim / Спасибо всем

Tuesday, October 18, 2011

Powder Coating System MK-II Progress


I have had a few questions and requests for additional documentation regarding my next powder coating machine build.

I have drawn up some proper schematics of the powder coating controller including the subsections for variable HV supply.

The full controller schematic is here:


You'll notice I just specified 28VDC input; its really up to you how to obtain this; you can get cheap switching modules off ebay; laptop power supplies, or you can build your own power supply with a transformer and rectifier (My preference as its most robust option).  I didn't go into it here as its pretty standard stuff

I have also done a schematic and board for just the HV supply; again its just a simple switching power supply which drives the flyback transformer.  There are other popular flyback drivers which use the resonance of the flyback itself to set the frequency, but I have found the timer based designs easiest to build and having the easiest to obtain parts.

Here is the schematic:


And the board layout:


I'm going to have boards made for this driver; If you're interested I'll be selling them for $10 each + $2 shipping (I will just send them as "letter mail").  Let me know via e-mail or comments if you're interested as that will get me motivated to put them up on the store http://www.thegreatgeekery.com/store/


I'm also playing with the idea of moving the flyback (and a HV cascade) onto the gun,  I havn't made too much progress in this area, just a box of parts really...


Saturday, September 24, 2011

Major news in the Roomote project

Brian Pratt, the developer of the Roomote iPhone app has released the source code for the client side (iOS app) and server side Mac OS app.

I have been working on a cross platform server application but now with full access to the source code it should really speed things up.

Progress has been a little slow on my port. I have the server auto discovery working using avahi in place of bonjour, working on the command decoding from the iPhone. It looks like the Roomote iPhone app doesn't use bit packed data structures which was causing issues with my decoding.

I have finished my prototype ultra low profile Roomba Bluetooth interface, I anticipate the circuit boards arriving this week. I'll post more details on this shortly.

Many thanks to Brian for sharing his hard work and helping me with my port.

Brian's Roomote Page
http://www.brianhpratt.net/cms/index.php?page=roomote

Brians Roomote github page:
http://github.com/brianpratt/roomote

My Github page:
https://github.com/scottjgibson/roomote


Sunday, August 21, 2011

Roomba iPhone Control

Started porting the OSX interface app for the roomote iphone interface.  Essentially it allows you to use your roomba as a little remote control bot which can play music and drive around.  Also allows you to see some diagnostic stuff.

Here is my github page:
https://github.com/scottjgibson/roomote

Here is the main roomote page which has the source for the OSX app:
http://www.brianhpratt.net/cms/index.php?page=roomote

Its been slow going because I'm working on a PCB for a low profile bluetooth roomba interface.

Here is a link to the roomote iPhone App:
http://itunes.apple.com/ca/app/roomote/id335355833?mt=8

Friday, August 19, 2011

Reception of Global-TV OTA DTV in Ottawa (Kanata)

Update: Nov 27th - Finally got it; see the bottom for details


Global TV started broadcasting in Digital (HD) over the air in mid august.  Like many others I was not able to receive it.

The Problem:
Due to the DTV Transition Global-TV Ottawa (Channel-6) has changed transmitters.  Their previous transmitter was 50KW; their new transmitter is 3KW...  As you can imagine its much more difficult to tune it in now.

My original setup:
- A digiwave 4-bay UHF antenna (ANT-2048 - which I bought for $20 at Canada Computers) in an upstairs bedroom, connected to a cheap radioshack distribution amplifier I have had for years

I was able to pick up Global TV analog with this setup despite using a UHF only antenna; and Global TV being on Channel 6 (VHF-Low band).

Here is my tvfool report: http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d9e748956995e10

First Attempt:
In looking for the cheapest possible solution I have decided to add a VHF-Low dipole (rabbit ears - extended horizontally) to my setup; as well as replace the distribution amplifier with a UHF/VHF combiner - amplifier

First Attempt Equipment:
- VHF Dipole (Rabbit Ears): http://www.thesource.ca/estore/product.aspx?language=en-CA&catalog=Online&category=Indoor+Antennas&product=1500235
- UHF/VHF Combiner / preamp thing:  Digiwave ANT-1028: http://canadacomputers.com/product_info.php?cPath=164_165&item_id=021144

Some thoughts on the Digiwave ANT-1028:
(1) Don't buy it:  its seriously made as cheaply as I can ever imagine, the F connectors were loose, its not weather shielded; the ampilfier unit doesn't have F-connectors; you have to strip your coax and clamp it on to.  The connections on the combiner / preamp are not labelled at all.  You have to take the tin box apart and read the silkscreen on the pcb (which is under the connectors) to see what they are.  No instructions.

Update:
The good part is Canada Computers is a reputable company and they allowed me to return it without issue.

Here are some pictures of the construction of the device:




Results:
Didn't give me any better performance versus just my UHF antenna :( Infact many UHF channels came in worse compared to not using the amplifier/combiner.  CJOH was slightly clearer, but not much better.

Second Attempt:
http://www.otacanada.com to the rescue.  I stumbled across this site while searching for Canadian OTA suppliers.  I was happy to discover they share a store with motofoto in the Carlingwood mall in Ottawa.  I visited one lunch hour and boy was I surprised, nice to find a small business which stocks this stuff and knows what they're talking about.  I definitely would recommend them to anyone looking for OTA stuff in Ottawa, they even have an antenna guide on their website: http://www.otacanada.com/cgi-bin/ota_recs.pl

Second Attempt Equipment:
- VHF Dipole (Rabbit Ears): http://www.thesource.ca/estore/product.aspx?language=en-CA&catalog=Online&category=Indoor+Antennas&product=1500235
- Channel Master CM-7777

CM-7777 impression:
- Huge step up from the digiwave (also more than twice the price mind you).  Build quality is excellent; its actually shielded properly, includes instructions and labelled connectors, as well as an FM trap which is good when trying to receive channel 6.



Results:
This box made a huge difference compared to not; and compared to the digiwave box.  I now receive 20 OTA channels; but unfortunately still no global...  But all other channels are clearer and have better strength.



Attempt 3: Diy Folded Dipole
I followed this guide (http://www.wfu.edu/~matthews/misc/dipole.html)  to determine the length of antenna to make.

Jeff at http://www.otacanada.com was nice enough to sell me some 300ohm wire for cheap, so for channel 6 (centered at 85MHz)
The wavelength on 300ohm twin-lead is 3.352 meters; so the antenna length is half that; at 1.676m.  I installed a 300-75ohm converter right at the antenna.

Update:
I soldered up the antenna; but no luck receiving global.  No better reception compared to rabbit ears.


Update: Moving to the antennas to the attic worked; so I gave up on this...  Attempt 4 (A)  DIY Channel 6 Tuned Yagi:
Starting to plan a build of a "Channel Cut" directional Yagi antenna tuned for channel 6.


Since it will be going in the attic; not much needed in the way of weather proofing;  So I'm going to go with a design with a wood frame and copper wire based directors / reflector.


Planning a design similar to this:
http://members.ziggo.nl/astrid.vanunnik/446/446pmrantyagi.htm


I have decided that before I attempt taking on a new antenna; I'll move my setup to the attic

Attempt 4 (B)  Antennas to the attic:
I'm in progress of moving my antennas to the attic of my home; I don't want to put them outside for cosmetic reasons, so I thought I would try the attic before building a new antenna (which would need to go in the attic anyways).


having a house built in the 80's there is no convenient way to get the wire into the attic.  I have resorted to running the coax to the second floor via a cold air return; then going to the attic in the corner of the closet (which backs on to the same cold air return).  Not an easy task as the cold air return has some corners in it.  I have had success using a wire pulling fish.  I am using this one: http://www.princessauto.com/workshop/hand-tools/measuring-tools/distance-measuring/8067944-50-ft-fish-tape-with-lighted-end it works quite well (though I have never bothered with the illuminated end) and its cheap and available locally.

Update - Nov 27th 2011


Finally got some coax to the attic.  No luck getting global with rabbit ears; but I finally had success with my home made folded dipole.  With everything pointed properly I know get all of the local stations!  So I'm using my home made channel folded dipole pointed at camp fortune; and my 4 bay UHF pointed at HC.  These antennas are combined with a CM-7777.




Resources;
Global-TV Ottawa Reception Thread:http://www.digitalhome.ca/forum/showthread.php?t=143890
Current Digital TV Broadasting Status: http://www.user.dccnet.com/jonleblanc/Canada_TV_Stations/DT.html



Tuesday, August 9, 2011

Roomba router fail...

So I got my little linux router all fixed up and connected to the roomba.  I compiled a little test program to send some commands to the roomba to make it move, it worked!

Now I went on to power the router via the SCI port on the roomba.  From what I have read the power is essentially a tap directly off the battery.  So I connected it up and it worked, at first...

Shortly after connecting it the roomba started making the uh-oh sound, over and over again; :(  So I powered it off and back on with everything disconnected and it kept making the same sound; plugged it in to charge; same sound.

The only way that I could get it to stop making sad noised was to do the battery reset procedure.

Starting to work on a plan-B for networking the roomba; going with a simple bluetooth serial bridge.

Saturday, August 6, 2011

Belkin F7D3302 Hacking

I bought a cheap Wireless-N router which supports USB the Belkin F7D3302.

http://en-us-support.belkin.com/app/product/detail/p/5132

Immediately I loaded dd-wrt on it, and got hacking.


How to install DD-WRT on Belkin F7D3302
http://www.dd-wrt.com/phpBB2/viewtopic.php?p=603693&sid=7edc20fe8941b0c8001cf0039d3de589




Seems no one has yet documented the power supply or serial port (Which I'm planning on using for controlling my Roomba)

Serial Port:
Connector J3 - already has header :)

Pin 1: Vcc (3.3V)
Pin 2:RX
Pin 3:TX
Pin 4: Gnd

I hooked it up using my trusty Bus Pirate, I don't know how I did things without it; its seriously the most useful and important tool I have.

Below is a capture of the bus pirate session; and monitoring the bootup of the router.




No mode set, M for mode
HiZ>
* Syntax error, type ? for help
HiZ>m
1. HiZ
2. 1-WIRE
3. UART
4. I2C
5. SPI
6. JTAG
7. RAW2WIRE
8. RAW3WIRE
9. PC KEYBOARD
10. LCD
(1) >3
Mode selected
Set serial port speed: (bps)
1. 300
2. 1200
3. 2400
4. 4800
5. 9600
6. 19200
7. 38400
8. 57600
9. 115200
10. 31250 (MIDI)
(1) >9
Data bits and parity:
1. 8, NONE *default
2. 8, EVEN
3. 8, ODD
4. 9, NONE
(1) >
Stop bits:
1. 1 *default
2. 2
(1) >
Receive polarity:
1. Idle 1 *default
2. Idle 0
(1) >
Select output type:
1. Open drain (H=Hi-Z, L=GND)
2. Normal (H=3.3V, L=GND)
(1) >
READY
UART>
* Syntax error, type ? for help
UART>
* Syntax error, type ? for help
UART>?
MENUS
? Help
I Status info
M Bus mode
B Terminal speed
O Data display format
V Check supply voltages
F Frequency count on AUX
G Frequency generator/PWM on AUX
C AUX pin assignment
L Bit order
P Pullup resistors
= HEX/DEC/BIN converter
~ Self test
# Reset
$ Bootloader
SYNTAX
A/a/@ AUX output toggle H/L/read
W/w Power supply toggle on/off
d (D) Measure voltage on ADC probe (continuous)
[ ({) Start (with read)
] or } Stop
R or r Read byte
0b Write BIN byte
0h or 0x Write HEX byte
0-255 Write DEC byte
, Delimiter (also space)
& 1uS delay
: Repeat (r:2, 0x0a:4, &:20, ^:2, etc.)
(#) Run macro, (0) for macro list
RAW BUS OPERATIONS
/\ Clock H/L
-/_ Data H/L
. Read data input pin state
^ Clock tick
! Read bit
UART>(0)
0.Macro menu
1.Transparent UART bridge
2. Live UART monitor
3.UART bridge with flow control
UART>(2)
Raw UART input. Space to exit.
Decompressing...done
Decompressing...done
Init Arena
Init Devs.
Boot partition size = 131072(0x20000)
et0: Broadcom BCM47XX 10/100/1000 Mbps Ethernet Controller 5.10.128.0
CPU type 0x19740: 453MHz
Tot mem: 65536 KBytes
CFE mem: 0x80700000 - 0x8079A400 (631808)
Data: 0x80731500 - 0x807338B0 (9136)
BSS: 0x807338B0 - 0x80734400 (2896)
Heap: 0x80734400 - 0x80798400 (409600)
Stack: 0x80798400 - 0x8079A400 (8192)
Text: 0x80700000 - 0x80731500 (201984)
Copying boot params.....DONE
Bootloader version 0.08e boot_version 0.08e
Project name : WG7016F22 1-LF-AK
Press space bar to cancel startup...
Device eth0: hwaddr 94-44-52-99-E0-4B, ipaddr 192.168.1.50, mask 255.255.255.0
gateway not set, nameserver not set
Loader:raw Filesys:raw Dev:flash0.os File: Options:(null)
Loading: .. 3916 bytes read
Entry at 0x80001000
Closing network.
Starting program at 0x80001000
Linux version 2.6.24.111 (eko@dd-wrt) (gcc version 4.1.2) #3050 Tue May 17 17:23:53 CEST 2011
CPU revision is: 00019740
Determined physical RAM map:
memory: 04000000 @ 00000000 (usable)
Zone PFN ranges:
Normal 0 -> 16384
HighMem 16384 -> 16384
Movable zone start PFN for each node
early_node_map[1] active PFN ranges
0: 0 -> 16384
Built 1 zonelists in Zone order. Total pages: 16384
Kernel command line: console=ttyS0,115200 root=1f02 rootfstype=squashfs noinitrd
Primary instruction cache 32kB, physically tagged, 4-way, linesize 32 bytes.
Primary data cache 32kB, 4-way, linesize 32 bytes.
Synthesized TLB refill handler (20 instructions).
Synthesized TLB load handler fastpath (32 instructions).
Synthesized TLB store handler fastpath (32 instructions).
Synthesized TLB modify handler fastpath (31 instructions).
PID hash table entries: 512 (order: 9, 2048 bytes)
CPU: BCM4716 rev 1 at 453 MHz
Using 226.500 MHz high precision timer.
console [ttyS0] enabled
Dentry cache hash table entries: 8192 (order: 3, 32768 bytes)
Inode-cache hash table entries: 4096 (order: 2, 16384 bytes)
Memory: 58732k/65536k available (3386k kernel code, 6748k reserved, 1437k data, 188k init, 0k highmem)
Mount-cache hash table entries: 512
NET: Registered protocol family 16
Generic PHY: Registered new driver
PCI: Using membase 8000000
PCI: Initializing host
PCI: Reset RC
PCI: no core
PCI: Fixing up bus 0
PCI/PCIe coreunit 0 is set to bus 1.
PCI: Fixing up bridge
PCI: Fixing up bridge
PCI: Enabling device 0000:01:00.1 (0004 -> 0006)
PCI: Fixing up bus 1
Device 0 map irq 0
result->irq 6
HND PCIE device corerev 14 found at 1/0/0
Device 0 map irq 0
result->irq 6
HND PCIE device corerev 14 found at 1/0/1
NET: Registered protocol family 2
Time: MIPS clocksource has been installed.
IP route cache hash table entries: 1024 (order: 0, 4096 bytes)
TCP established hash table entries: 2048 (order: 2, 16384 bytes)
TCP bind hash table entries: 2048 (order: 1, 8192 bytes)
TCP: Hash tables configured (established 2048 bind 2048)
TCP reno registered
F7D3301v1/3302v1/4302v1 - F5D8235v3 GPIO Init
devfs: 2004-01-31 Richard Gooch (rgooch@atnf.csiro.au)
devfs: boot_options: 0x1
squashfs: version 3.0 (2006/03/15) Phillip Lougher
io scheduler noop registered
io scheduler deadline registered (default)
HDLC line discipline: version $Revision: 4.8 $, maxframe=4096
N_HDLC line discipline registered.
Serial: 8250/16550 driver $Revision: 1.90 $ 4 ports, IRQ sharing disabled
serial8250: ttyS0 at MMIO 0x0 (irq = 8) is a 16550A
PPP generic driver version 2.4.2
PPP Deflate Compression module registered
PPP BSD Compression module registered
MPPE/MPPC encryption/compression module registered
NET: Registered protocol family 24
PPPoL2TP kernel driver, V1.0
tun: Universal TUN/TAP device driver, 1.6
tun: (C) 1999-2004 Max Krasnyansky
eth0: Broadcom BCM47XX 10/100/1000 Mbps Ethernet Controller 5.60.127.4
Physically mapped flash: Found 1 x16 devices at 0x0 in 8-bit bank
Amd/Fujitsu Extended Query Table at 0x0040
number of CFI chips: 1
cfi_cmdset_0002: Disabling erase-suspend-program due to code brokenness.
Flash device: 0x800000 at 0x1c000000
Found Belkin TRX magic
bootloader size: 196608
nvram size: 32768
Found Belkin TRX magic
Physically mapped flash: Filesystem type: squashfs, size=0x6049fb
partition size = 6315008
Creating 5 MTD partitions on "Physically mapped flash":
0x00000000-0x00030000 : "cfe"
0x00030000-0x007f0000 : "linux"
0x0018a400-0x00790000 : "rootfs"
mtd: partition "rootfs" doesn't start on an erase block boundary -- force read-only
0x007f0000-0x00800000 : "nvram"
0x00790000-0x007f0000 : "ddwrt"
Found a 0MB serial flash
sflash: found no supported devices
Broadcom Watchdog Timer: 0.07 initialized.
u32 classifier
Actions configured
Netfilter messages via NETLINK v0.30.
nf_conntrack version 0.5.0 (1024 buckets, 4096 max)
ctnetlink v0.93: registering with nfnetlink.
IPv4 over IPv4 tunneling driver
GRE over IPv4 tunneling driver
ip_tables: (C) 2000-2006 Netfilter Core Team
ClusterIP Version 0.8 loaded successfully
TCP bic registered
TCP cubic registered
TCP westwood registered
TCP highspeed registered
TCP hybla registered
TCP htcp registered
TCP vegas registered
TCP scalable registered
NET: Registered protocol family 1
NET: Registered protocol family 17
Welcome to PF_RING 3.2.1
(C) 2004-06 L.Deri
NET: Registered protocol family 27
PF_RING: bucket length 128 bytes
PF_RING: ring slots 4096
PF_RING: sample rate 1 [1=no sampling]
PF_RING: capture TX No [RX only]
PF_RING: transparent mode Yes
PF_RING initialized correctly.
PF_RING: registered /proc/net/pf_ring/
802.1Q VLAN Support v1.8 Ben Greear
All bugs added by David S. Miller
decode 1f02
VFS: Mounted root (squashfs filesystem) readonly.
Mounted devfs on /dev
Freeing unused kernel memory: 188k freed
start service
starting Architecture code for broadcom
starting hotplug
done
Booting device: Belkin F7D3302 / F7D7302 v1
loading switch-core
loading switch-robo
roboswitch: Probing device eth0: found a 5325!
[USB] checking...
usbcore: registered new interface driver usbfs
usbcore: registered new interface driver hub
usbcore: registered new device driver usb
USB20H mdio control register : 0x80000008
ehci_hcd 0000:00:04.1: EHCI Host Controller
ehci_hcd 0000:00:04.1: new USB bus registered, assigned bus number 1
ehci_hcd 0000:00:04.1: irq 5, io mem 0x18004000
ehci_hcd 0000:00:04.1: USB 0.0 started, EHCI 1.00, driver 10 Dec 2004
usb usb1: configuration #1 chosen from 1 choice
hub 1-0:1.0: USB hub found
hub 1-0:1.0: 2 ports detected
USB Universal Host Controller Interface driver v3.0
USB20H mdio control register : 0x80000008
ohci_hcd 0000:00:04.0: OHCI Host Controller
ohci_hcd 0000:00:04.0: new USB bus registered, assigned bus number 2
ohci_hcd 0000:00:04.0: irq 5, io mem 0x18009000
usb 1-1: new high speed USB device using ehci_hcd and address 2
usb usb2: configuration #1 chosen from 1 choice
hub 2-0:1.0: USB hub found
hub 2-0:1.0: 2 ports detected
usb 1-1: configuration #1 chosen from 1 choice
SCSI subsystem initialized
Initializing USB Mass Storage driver...
scsi0 : SCSI emulation for USB Mass Storage devices
usbcore: registered new interface driver usb-storage
USB Mass Storage support registered.
/bin/sh: can't create /proc/switch/eth1/reset: nonexistent directory
/etc/preinit: line 66: can't create /proc/sys/net/ipv4/ip_conntrack_max: nonexistent directory
/etc/preinit: line 66: can't create /proc/sys/net/ipv4/ip_conntrack_max: nonexistent directory
eth1: Operation not supported
wl0.1: No such device
wl0.2: No such device
wl0.3: No such device
eth1: Operation not permitted
nbw = 20
eth1: Invalid argument
eth1: Invalid argument
eth1: Operation not supported
eth1: Operation not supported
/bin/sh: can't create /proc/sys/net/bridge/bridge-nf-call-arptables: nonexistent directory
/bin/sh: can't create /proc/sys/net/bridge/bridge-nf-call-ip6tables: nonexistent directory
/bin/sh: can't create /proc/sys/net/bridge/bridge-nf-call-iptables: nonexistent directory
br0: Dropping NETIF_F_UFO since no NETIF_F_HW_CSUM feature.
device br0 entered promiscuous mode
br0: No such file or directory
device vlan1 entered promiscuous mode
device eth0 entered promiscuous mode
br0: No such file or directory
eth1: Operation not supported
wl0.1: No such device
wl0.2: No such device
wl0.3: No such device
eth1: Operation not permitted
eth1: Invalid argument
nbw = 20
eth1: Invalid argument
eth1: Invalid argument
eth1: Operation not supported
eth1: Operation not supported
device eth1 entered promiscuous mode
br0: No such file or directory
device vlan2 entered promiscuous mode
br0: port 3(vlan2) entering learning state
br0: port 2(eth1) entering learning state
br0: port 1(vlan1) entering learning state
device br0 left promiscuous mode
device br0 entered promiscuous mode
device br0 left promiscuous mode
device br0 entered promiscuous mode
scsi 0:0:0:0: Direct-Access OCZ ET1208AD 1.0 PQ: 0 ANSI: 2
sd 0:0:0:0: [sda] 4095999 512-byte hardware sectors (2097 MB)
sd 0:0:0:0: [sda] Write Protect is off
sd 0:0:0:0: [sda] Assuming drive cache: write through
sd 0:0:0:0: [sda] 4095999 512-byte hardware sectors (2097 MB)
sd 0:0:0:0: [sda] Write Protect is off
sd 0:0:0:0: [sda] Assuming drive cache: write through
/dev/scsi/host0/bus0/target0/lun0: p1
sd 0:0:0:0: [sda] Attached SCSI removable disk
br0: topology change detected, propagating
br0: port 3(vlan2) entering forwarding state
br0: topology change detected, propagating
br0: port 2(eth1) entering forwarding state
br0: topology change detected, propagating
br0: port 1(vlan1) entering forwarding state
Key is a RSA key
Wrote key to '/tmp/root/.ssh/ssh_host_rsa_key'
Key is a DSS key
Wrote key to '/tmp/root/.ssh/ssh_host_dss_key'
SIOCGIFFLAGS: No such device
/bin/sh: hdparm: not found
[USB Device] partition:
[USB Device] partition: --- /dev/discs/disc0/disc
[USB Device] partition: Block device, size 1.953 GiB (2097151488 bytes)
[USB Device] partition: DOS/MBR partition map
[USB Device] partition: Partition 1: 1.952 GiB (2096342016 bytes, 4094418 sectors from 62)
[USB Device] partition: Type 0x83 (Linux)
[USB Device] partition: Ext2 file system
[USB Device] file system: Ext2 file system
SIOCGIFFLAGS: No such device
SIOCGIFFLAGS: No such device
SIOCGIFFLAGS: No such device
etherip: Ethernet over IPv4 tunneling driver
The Milkfish Router Services
ERROR: Necessary service setting not found: milkfish_username - aborting.
The Milkfish Router Services
Restoring SIP ddsubscriber database from NVRAM...
Empty.
The Milkfish Router Services
Restoring SIP ddaliases database from NVRAM...
Empty.
UART>





Power Supply:
I measured the current on the input by removing; and it peaked at 400mA while reading USB, and at idle was around 300mA.

My next goal was to see if the power supply would accept the higher voltage from the Roomba; or if I would be required to step it down.

Below is a picture of the power supply; the input is 12VDC at maximum 1A.  By visual inspection I believe the power supply to have two primary rails;  A 5V rail used for USB; and a 3.3V Rail used for the logic.  There are linear regulators to drop the 3.3V rail to 1.8V for the main processor and the wired Ethernet switch.





3.3V Regulator:

  • Apw7080: 4A, 26V, 380kHz, Asynchronous Step-Down Converter
  • Datasheet: http://moddedreality.dreamhosters.com/Apw7080.pdf
  • 4.5 to 26V input
  • 3.3 or 5V output; in this case 3.3V
  • Pin 2 is enable; this may be useful for automatic power up/down of the router when interfaced to roomba
5V Regulator:
  • Zt1413s ASYNC switching regulator Input: 4.75~23V Output:0.92~15V 2A 380KHz 95% SOP8EPMP
  • Datasheets seem non existent for this regulator;

Reducing Power Consumption for battery powered operation:

I'm looking for ways to reduce the power consumption of the router because I'm planning on having it battery powered; currently drawing around 400mA @12V (4.8W) with USB connected its not too power hungry; but less the better. I havn't done full measurements with high traffic; at this point I'm getting some estimates.

Idea 1:
Add a means to remove power to the wired Ethernet switch.
Part: Broadcom BCM5325: http://www.broadcom.com/products/BCM5325
Power: The full datasheet isn't available; but in the product brief it says < 1.4W, assuming its around 1W idle (warm to the touch so this is likely a reasonable estimate); I could save 20% by removing power.

Near Ethernet Switch there is another regulator to drop the 3.3V rail to 1.8V

Ld1117a - http://www.st.com/stonline/products/literature/ds/2572.pdf

My plan is to add a switch to be able to switch the the wired ethernet switch on and off, I would prefer to have this controlled via software; I'll need to find a GPIO in order to do this. This way I can keep in on by default and power it off when connected to the roomba.

Thursday, May 19, 2011

Ontario Internet

Since Teksavvy and Acanac Cable have finally come to my area (West Ottawa) I have compiled a spreadsheet comparing prices of the options available to me (Bell, Rogers, Teksavvy, Acanac)

I used the raw data to calculate some interesting results;

Assumptions:
- Where possible Modem Purchase was chosen (as to not inflate monthly expenses with rental fees)
- Bundling or other promotions are not taken into consideration(bundling enters you in to long term contracts whether you're told or not)

Services Compared:
Bell Fibe (Not Fiber Optic; VDSL2 I think)
- Not sure if this is available to me; it seems to be about the worst overall in terms of price / performance

Specs:



             Downlink Speed (Mbps) UplinkSpeed (kbps) Usage Allowance (GB)  
Fibe 6       6                     1024               25
Fibe 12      12                    1024               50
Fibe 16      16                    1024               75
Fibe 25      25                    7168               75

Monthly Fees:
         Monthly Cost  Modem Rent  Monthly Cost  Over. Charge/GB  Max Overage Charge

Fibe 6   $44.95        $3.95        $44.95        $2.00            $60.00
Fibe 12  $54.95        $3.95        $54.95        $1.50            $60.00
Fibe 16  $64.95        $3.95        $64.95        $1.00            $60.00
Fibe 25  $70.95        $6.95        $70.95        $1.00            $60.00

Startup Fees:
Bell                      Activation Fee  Modem Purchase Price
Fibe 6                    $29.95          N/A
Fibe 12                   $29.95          N/A
Fibe 16                   $29.95          N/A
Fibe 25                   $29.95          N/A


Rogers Cable Internet (DOCSIS 3.0)
- Rogers offers the highest performance internet in my area (up to 50MBps) however it couples them with low caps (you will reach the Cap within 8 hours)!

Specs:

                   Downlink Speed (Mbps) UplinkSpeed (kbps) Usage Allowance (GB)
Ultralite          0.5                   256                2
lite               3                     256                15
express            10                    512                60
extreme            15                    1024               80
extreme plus       25                    1024               125
ultimate           50                    2048               175

Monthly Fees:

              Monthly Cost  Modem Rental  Monthly Cost  Overage / GB  Max Overage
Ultralite     $27.99        $0.00         $27.99        $5.00         $50.00
lite          $35.99        $0.00         $35.99        $4.00         $50.00
express       $46.99        $0.00         $46.99        $2.00         $50.00
extreme       $59.99        $0.00         $59.99        $1.50         $50.00
extreme plus  $69.99        $0.00         $69.99        $1.25         $50.00
ultimate      $99.99        $0.00         $99.99        $0.50         $50.00

Startup Fees:
Rogers                    Activation Fee  Modem Purchase Price
Ultralite                 $14.95          $99.99
lite                      $14.95          $99.99
express                   $14.95          $200.00
extreme                   $14.95          $200.00
extreme plus              $14.95          $200.00
ultimate                  $14.95          $200.00

Teksavvy Cable Internet (DOCSIS 3.0)
- Just started reselling rogers cable internet a couple of weeks ago in my area

Specs:

Teksavvy        Downlink Speed (Mbps) UplinkSpeed (kbps) Usage Allowance (GB)
Cable (Lite)    3                     256                300
Cable (Express) 10                    512                300
Cable (Extreme) 15                    1024               300
Cable (Pro)     15                    1024               Unlimited

Monthly Fees:

Teksavvy        Monthly Cost  Modem Rental  Monthly Cost  Overage Charge per GB  Max Overage Charge
Cable (Lite)    $27.95        $0.00         $27.95        $0.50                  Unlimited
Cable (Express) $36.95        $0.00         $36.95        $0.50                  Unlimited
Cable (Extreme) $42.95        $0.00         $42.95        $0.50                  Unlimited
Cable (Pro)     $54.95        $0.00         $54.95        $0.00                  N/A

Startup Fees:
Teksavvy           Activation Fee  Modem Purchase Price
Cable (Lite)       $44.95          $65.00
Cable (Express)    $44.95          $65.00
Cable (Extreme)    $44.95          $65.00
Cable (Pro)        $44.95          $65.00

Acanac Cable Internet (DOCSIS 3.0)

- Just started reselling rogers cable internet a couple of weeks ago in my area
- Prices based on length of sign up; I prices both by the month and by the year


Acanac (Monthly Payment) Downlink Speed (Mbps) UplinkSpeed (kbps) Usage Allowance (GB)
Cable 7.5 (Capped)       7.5                   800                40
Cable 10 (Capped)        10                    1024               60
Cable 10 (Unlimited)     10                    512                Unlimited
Cable 15 (Unlimited)     15                    1024               Unlimited


Acanac (Monthly Payment) Monthly Cost  Modem Rental  Monthly Cost  Overage Charge per GB  Max Overage Charge
Cable 7.5 (Capped)       $37.95        $0.00         $37.95        $4.50                  $50.00
Cable 10 (Capped)        $58.95        $0.00         $58.95        $1.65                  Unlimited
Cable 10 (Unlimited)     $44.95        $0.00         $44.95        $0.00                  N/A
Cable 15 (Unlimited)     $48.95        $0.00         $48.95        $0.00                  N/A

Acanac (Monthly Payment)  Activation Fee  Modem Purchase Price
Cable 7.5 (Capped)        $29.95          $50.00
Cable 10 (Capped)         $29.95          $50.00
Cable 10 (Unlimited)      $29.95          $50.00
Cable 15 (Unlimited)      $29.95          $50.00



Acanac (Yearly Payment)  Downlink Speed (Mbps) UplinkSpeed (kbps) Usage Allowance (GB)
Cable 7.5 (Capped)       7.5                   800                40
Cable 10 (Capped)        10                    1024               60
Cable 10 (Unlimited)     10                    512                Unlimited
Cable 15 (Unlimited)     15                    1024               Unlimited

Acanac (Yearly Payment)  Monthly Cost  Modem Rental  Monthly Cost  Overage Charge per GB  Max Overage Charge
Cable 7.5 (Capped)       $37.95        $0.00         $37.95        $4.50                  $50.00
Cable 10 (Capped)        $58.95        $0.00         $58.95        $1.65                  Unlimited
Cable 10 (Unlimited)     $35.95        $0.00         $35.95        $0.00                  N/A
Cable 15 (Unlimited)     $39.95        $0.00         $39.95        $0.00                  N/A

Acanac (Yearly Payment)   Activation Fee  Modem Purchase Price
Cable 7.5 (Capped)        $29.95          $50.00
Cable 10 (Capped)         $29.95          $50.00
Cable 10 (Unlimited)      $29.95          $50.00
Cable 15 (Unlimited)      $29.95          $50.00













Cost Per Gigabyte (without overage charges):

Bell                 Cost / GB (without exceeding plan)
Fibe 6               $1.96
Fibe 12              $1.18
Fibe 16              $0.92
Fibe 25              $1.04


Rogers               Cost / GB (without exceeding plan)
Ultralite            $16.00
lite                 $2.67
express              $0.90
extreme              $0.84
extreme plus         $0.62
ultimate             $0.61


Teksavvy             Cost / GB (without exceeding plan)
Cable (Lite)         $0.09
Cable (Express)      $0.12
Cable (Extreme)      $0.14
Cable (Pro)          $0.00


Acanac (Monthly)     Cost / GB (without exceeding plan)
Cable 7.5 (Capped)   $0.95
Cable 10 (Capped)    $0.98
Cable 10 (Unlimited) $0.00
Cable 15 (Unlimited) $0.00


Acanac (Yearly)      Cost / GB (without exceeding plan)
Cable 7.5 (Capped)   $0.95
Cable 10 (Capped)    $0.98
Cable 10 (Unlimited) $0.00
Cable 15 (Unlimited) $0.00

Hours of Download at Max Rate
How many hours you can download at your maximum rate before you get charged overage fees:
Unlimited internet shows at 720 hours (30 days * 24 hours)

Bell                 Hours to reach cap 
Fibe 6               9
Fibe 12              9
Fibe 16              11
Fibe 25              7


Rogers               Hours to reach cap
Ultralite            9
lite                 11
express              14
extreme              12
extreme plus         11
ultimate             8


Teksavvy             Hours to reach cap
Cable (Lite)         228
Cable (Express)      68
Cable (Extreme)      46
Cable (Pro)          720


Acanac (Monthly)     Hours to reach cap
Cable 7.5 (Capped)   12
Cable 10 (Capped)    14
Cable 10 (Unlimited) 720
Cable 15 (Unlimited) 720


Acanac (Yearly)      Hours to reach cap
Cable 7.5 (Capped)   12
Cable 10 (Capped)    14
Cable 10 (Unlimited) 720
Cable 15 (Unlimited) 720

Cost Per Hour Of Netflix

Bell                 Cost Per Hour (default) Cost Per Hour (HD)  
Fibe 6               $0.59                   $1.96               
Fibe 12              $0.35                   $1.18               
Fibe 16              $0.28                   $0.92               
Fibe 25              $0.31                   $1.04               


Rogers               Cost Per Hour (default) Cost Per Hour (HD)  
Ultralite            $4.80                   $16.00              
lite                 $0.80                   $2.67               
express              $0.27                   $0.90               
extreme              $0.25                   $0.84               
extreme plus         $0.18                   $0.62               
ultimate             $0.18                   $0.61               


Teksavvy             Cost Per Hour (default) Cost Per Hour (HD)  
Cable (Lite)         $0.03                   $0.09               
Cable (Express)      $0.04                   $0.12               
Cable (Extreme)      $0.04                   $0.14               
Cable (Pro)          $0.08                   $0.08               


Acanac (Monthly)     Cost Per Hour (default) Cost Per Hour (HD)  
Cable 7.5 (Capped)   $0.28                   $0.95               
Cable 10 (Capped)    $0.29                   $0.98               
Cable 10 (Unlimited) $0.06                   $0.06               
Cable 15 (Unlimited) $0.07                   $0.07               


Acanac (Yearly)      Cost Per Hour (default) Cost Per Hour (HD)  
Cable 7.5 (Capped)   $0.28                   $0.95               
Cable 10 (Capped)    $0.29                   $0.98               
Cable 10 (Unlimited) $0.05                   $0.05               
Cable 15 (Unlimited) $0.06                   $0.06            



All The Data!


Tuesday, May 3, 2011

Pressure Cooker Vacuum Chamber

Some pics of my pressure cooker to vacuum chamber conversion.  I used a $6 aluminum pressure cooker I found at the salvation army.

I removed the pressure release and tapped a 1/4" NPT hole for a hose barb connection.  I then milled a flat area and window to mount some lexan.


 Setting up the lid for milling

Milling the window on my drill press and X/Y table

Completed Result:


I used RTV silicone to mount the lexan window

Tuesday, April 12, 2011

Auto Macro Stacker

Intro:
This project is some hardware and software which allow precise positioning of a camera for taking multiple macro shots at fixed positions such that the images can be "stacked" in software to obtain a an image which is fully in focus.

When shooting with a macro lens typically the depth of focus is very small (1-2mm), so to take an image of something you need to combine multiple pictures.

So with this project; I specifies how many shots I want to take; and how many millimeters the shots are to be and the rest is automatic.  The hardware moves the camera the right distance and controls the shutter of the camera; and repeats for all the shots.  Check out the videos at the bottom of the post.

Here is the latest video:




Mechanical - Initial Prototype
- The hardware is essentially a threaded rod with a stepper attached which allows for precise positioning of the camera.
I used mostly recycled materials for the first build:

  • Plywood ($0 scraps lying around from other projects)
  • 3/8" steel rods ($0; taken from some old printers from the trash)
  • Stepper Motor and gears($0; again taken from old printers from the trash)
  • Plastic slider; surplus UHMW (similar to delrin/acetal), bought for $4 a pound, I used about $1's worth
  • 1/2" ACME threaded rod, left over from another project; though you can use regular cheap threaded rod from the hardware store
  • Brass Bushings; not really necessary; I used a single 3/8" brass bushing cut in two ($3)


Building the linear rail:
Frame:
I sized the frame such that the stepper could sit inside, I made the length long enough to fit my left over section of threaded rod (8")

Drilling:
This is the trickiest part of the build; the holes have to be well aligned for the slide not to bind.  I did this by clamping both end pieces and the slider together and drilling the three holes at the same time.

I laid out the two parallel rods such that they were 4" apart with the threaded rod running down the middle.

Threading the rod through the slider:
To do this I filed some slots in the end of a scrap of ACME lead screw, I then heated up the screw a bit and tapped the hole.  It a few passes until it became smooth.







I turned a 1/2" from the ends of the lead screw such that they would fit in the brass bushings; this is probably overkill for this situation; since its not a CNC machine there is minimal load on the screw; I'm pretty sure it would be fine just running the threads through a larger hole in the plywood.





Results turned out ok; but it really needs brass sliders instead of just using the UHMW directly on the rail.  The UHMW plastic seemed to bind on the rail occastionally which made the motion less smooth.





I've moved on to MK-II since I scored a great little linear rail from a friend of mine; The initial prototype works its just not as cool looking :)


Mechanical MK-II:
For MK-II I machined some brackets from UHMW-PE and used a Z-axis a friend of mine provided.  He got three of the Z-axis on e-bay cheap.  The white bits are the brackets I machined on my drill press.











Electronics:
To keep it simple I decided on a simple USB interface (could easily have done a microcontroller based solution (I may do this in the future); I used the FTDI FT232R since it supports bit-banged mode; I paired this with a standard stepper driver from pololu.  I also added shutter control.

Pretty basic stuff here:
- FTDI FT232R USB interface
- Alegro A4983 stepper driver
- NPN transistor for the shutter control

Schematic is a bit of a work in progress:



I assembled it on protoboard; but I'm in the process of building some PCBs; let me know if you're interested in one once they're made; I'll have some extras.







Software:
The software is pretty straight forward; I put the source up on github:

Its currently just a command line utility; still a work in progress; but its working.

https://github.com/scottjgibson/camera-motion-controls

Stacking Software:

Check this out for a comparison of software:
http://chdk.wikia.com/wiki/Stacking_Software
I ended up using Helicon Focus


Results:

Setup:
- I'm using a standard kit Canon 18-55 mounted backwards; makes for a pretty sharp macro lens.



Here is one of the images from the first set I took; as you can see only a small area is in focus.



I did a run and stacked the 30 images together to obtain the following result; not great but I'm happy with it for a first try.



Here is are some videos of the rig in action:


The macro stacking software can generate a 3D model based on the stack of photos:

Sunday, February 27, 2011

Stepper Wiring

Tek-flex and adhesive lined heat shink tubing; connectors are Molex C-Grid series.


Friday, January 28, 2011

Workshop

Some pics from the share your workspace thread on hackaday