HW
I did it again!.
This year, I gave a talk on reverse-engineering a commercial coffee machine.
Clarification, the title was supposed to be “Sudo Make Me a Coffee: Adventures in Reverse-Engineering a Commercial Coffee Machine” (Sudo without comma, referring to UNIX command sudo)
Video recording has been posted on Youtube:
Pyramid PS36KX is one of the few power supplies I have for my radios. Recently I decided to consolidate and hook up more radios to a single PSU via powerpoles, it makes everything easier.
One problem with the Pyramid is noise, it’s *extremely* loud, with just a single fan.
Pop goes the chassis, one cheapo 24V fan is the culprit, no speed control, only 2 wires.
Quick throwback to computer days, and here come TWO 12V quiet noctua fans, I used the NF-A8-FLX model which come with lots of options by default, including rubber dampeners.
Both fans are connected in series to make them work under 24V, I cut the yellow (RPM sense) wire, hooked up both fans and installed them.
One went in place of the original 24V fan, and another across the case, near the AMP gauge.
I did have to drill 2 holes in the chassis to attach the new fan, and it doesn’t perfectly overlap with the holes in the top case, but it’s good enough.
Overall cost was pretty low, some labor and cost of two quality fans, but the result is stunning, near absolute silence, makes a lot of difference listening to the radio.
Update 2024. The PSU broke at some point, seems like a common failure – the RED Overload LED was on and the buzzer was beeping.
I ended up replacing the NTE Rectifier with an NTE5556-I version and the PSU is back in business!
Cheers
Just stumbled on this article https://jcs.org/2018/06/12/airport_ssh and I just had to try it out on my Airport Express, even though the method was for the Extreme.
It worked like a charm, as easy as:
python -m acp -t 192.168.234.189 -p xxx --setprop dbug 0x3000
python -m acp -t 192.168.234.189 -p xxx --reboot
Dmesg:
ry = 49844 KB
mainbus0 (root)
cpu0 at mainbus0: Marvell 88F6183 rev 2 (ARMv5TE core) [88F6183 Rev 3]
cpu0: WB enabled EABT
cpu0: 32KB/32B 1-way Instruction cache
cpu0: 32KB/32B 4-way write-back Data cache
cpu0: This kernel does not fully support this CPU.
cpu0: Recompile with "options CPU_ARMV5TE" to correct this.
mbus0 at mainbus0 base 0xf1020000 irq 0: AHB to MBUS Bridge
mvaud0 at mbus0audio0 at mvaud0: full duplex, mmap, independent
mv_audiodec_init: bypassed
mvdevb0 at mbus0 target 1, irq 15: Device Bus
com0 at mvdevb0 offset 0x2000, irq 3: ns16550a, working fifo
com0: console
com1 at mvdevb0 offset 0x2100, irq 4: ns16550a, working fifo
mvtwsi0 at mvdevb0 offset 0x1000, irq 5: Two Wire Serial Interface
mvtwsi0: I2C clocked at 94.696 Khz
iic0 at mvtwsi0: I2C bus
stdflash_orion_match: flash width 4213/0
stdflash0 at mvdevb0 DevCS1: Onboard SPIBootFlash
this is a spansion part...we should check the spansion specific subid (6 entries)
FLASH look for .... 0) 1/2018/20/2018
FLASH look for .... 1) 1/2018/c2/2017
FLASH look for .... 2) 1/2018/c2/2018
FLASH look for .... 3) 1/2018/c2/2013
FLASH look for .... 4) 1/2018/ef/4018
FLASH look for .... 5) 1/2018/1/2018
FLASH SUPPORTED.... 1/2018/5/0
flash0 at stdflash0 00000000-00700000, untranslated, read/write
flash1 at stdflash0 00700000-00e00000, untranslated, read/write
flash2 at stdflash0 00e00000-00f40000, translated, read/write
flash3 at stdflash0 00f40000-00f80000, untranslated, read/write
flash4 at stdflash0 00f80000-01000000, untranslated, read/write
applgpio0 at mvdevb0 offset 0x0000GPIO_interrupt_pin_ex: flipping pin 17.
GPIO_interrupt_pin_ex: flipping pin 3.
(board-revision=-1)
mvgec0 at mbus0 target 7, irq 22: Gigabit Ethernet Global Controller
gec0 at mvgec0 unit 0, irq 18: Gigabit Ethernet Controller, Unit 0
gec0: MAC address: 00:16:cb:00:51:81
makphy0 at gec0 phy 8: Marvell 88E3016 Gigabit PHY, rev. 0
makphy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
mvusb0 at mbus0 target 5, irq 16: ARC USB-HS Host/Device Controller
mvusb0: Core revision 4.0
ehci0 at mvusb0 irq 17, host mode: USB Host Controller
ehci0: EHCI version 1.0
usb0 at ehci0: USB revision 2.0, available bus power 500 mA
uhub0 at usb0
uhub0: ARC USB-HS Core EHCI root hub, class 9/0, rev 2.00/1.00, addr 1
ehci0: self-powered device addr 1 (config 1) power 0 mA. Available power 500 mA (root)
uhub0: 1 port with 1 removable, self powered
mvpcie0 at mbus0 target 4, irq 10: PCI Express Controller
mvpcie_attach() - bus_num = 0, if_num = 0.
PEX0 interface detected Link X1
mvpcie0: INTn interrupting on irq 11
pci0 at mvpcie0 bus 0
pci0: i/o space, memory space enabled
mv0 at pci0 dev 1 function 0
mv0: interrupting at INTA
mv0: load
wlan: mac acl policy registered
mv0: 11a rates: 6Mbps 9Mbps 12Mbps 18Mbps 24Mbps 36Mbps 48Mbps 54Mbps
mv0: 11b rates: 1Mbps 2Mbps 5.5Mbps 11Mbps
mv0: 11g rates: 1Mbps 2Mbps 5.5Mbps 11Mbps 6Mbps 9Mbps 12Mbps 18Mbps 24Mbps 36Mbps 48Mbps 54Mbps
mv0: 11na MCS: 15Mbps 30Mbps 45Mbps 60Mbps 90Mbps 120Mbps 135Mbps 150Mbps 30Mbps 60Mbps 90Mbps 120Mbps 180Mbps 240Mbps 270Mbps 300Mbps
mv0: 11ng MCS: 15Mbps 30Mbps 45Mbps 60Mbps 90Mbps 120Mbps 135Mbps 150Mbps 30Mbps 60Mbps 90Mbps 120Mbps 180Mbps 240Mbps 270Mbps 300Mbps
mv0: versions [driver 0.8.7.0 hw 5 fw 3.7.2.2] (regioncode 16)
mv0: multi-bss support
mvidma0 at mbus0 target 6, irq 24: IDMA Controller
mvidma0: DMA Assist enabled for copyin/copyout and copy/zero page on channel 3
mvaud1 at mbus0 target 5audio1 at mvaud1: full duplex, mmap, independent
mv_audiodec_init: bypassed
clock: hz=100 stathz=0 profhz=0
md0: internal 10240 KB image area
IPsec: Initialized Security Association Processing.
boot device:
root on md0a dumps on md0b
root file system type: ffs
WARNING: no TOD clock present
WARNING: using filesystem time
WARNING: CHECK AND RESET THE DATE!
Filesystem:
Filesystem Size Used Avail Capacity Mounted on
/dev/md0a 9.7M 7.7M 2.0M 79% /
/dev/flash2a 1.1M 41K 1.0M 3% /mnt/Flash
mfs:141 15M 512B 14M 0% /mnt/Memory
Running processes (with airtunes enabled):
PID TTY STAT TIME COMMAND
0 ? DKs 0:00.01 [swapper]
1 ? Is 0:00.02 init
2 ? DK 0:05.30 [stdflash0]
3 ? DK 0:00.00 [usb0]
4 ? DK 0:00.00 [usbtask-hc]
5 ? DK 0:00.00 [usbtask-dr]
6 ? DK 0:00.01 [pagedaemon]
7 ? DK 0:00.04 [ioflush]
8 ? DK 0:00.01 [aiodoned]
9 ? DK 0:00.01 [sfdaemon]
18 ? DK 0:00.02 [physiod]
96 ? Ia 0:00.03 /sbin/sntpd -client=time.apple.com
97 ? I 0:00.35 /sbin/wpa_supplicant -K -M -F /var/log/hostap_wlan1.log -D net80211 -i wlan1 -c /etc/hostap_wlan1.conf
99 ? I 0:00.01 /sbin/iCloudd
141 ? Ss 0:00.03 mount_mfs -s 32768 swap /mnt/Memory
164 ? Ia 0:00.02 /sbin/airtunesd -i bridge0
175 ? Is 0:00.00 /usr/sbin/inetd -l
183 ? Is 0:00.01 /usr/sbin/cron
245 ? Sa 0:01.54 /sbin/mDNSResponder -d
253 ? I 0:00.74 /usr/sbin/sshd -D -e
271 ? Ss 0:00.87 sshd: root@ttyp0
415 ? I 0:00.03 /sbin/link_local bridge0
467 ? I 0:00.04 /sbin/dhclient -q -d
505 ? I 0:00.06 /sbin/snmpd -f -DALL -c /etc/snmpd.conf -p /var/run/snmpd.pid
539 ? Ia 0:00.22 /sbin/printd -i -d local.
604 ttyp0 R+ 0:00.00 ps -ax
627 ttyp0 Ss 0:00.05 -sh
94 tty00- S 0:00.06 svscan /var/sv
107 tty00- Ia 0:08.53 /sbin/ACPd -nofork
108 tty00- I 0:00.02 supervise dnscache
110 tty00- I 0:00.01 supervise walldns
112 tty00- I 0:00.01 supervise log
113 tty00- I 0:00.01 supervise log
116 tty00- I 0:00.01 cat -
118 tty00- I 0:00.02 cat -
184 tty00 Is+ 0:00.04 -sh
186 tty01 Is+ 0:00.05 -sh
It runs SNMP daemon:
snmpwalk -c public 192.168.234.189| head
SNMPv2-MIB::sysDescr.0 = STRING: Apple AirPort - Apple Inc., 2006-2012. All rights Reserved.
SNMPv2-MIB::sysObjectID.0 = OID: NET-SNMP-MIB::netSnmpAgentOIDs.255
DISMAN-EVENT-MIB::sysUpTimeInstance = Timeticks: (2064754916) 238 days, 23:25:49.16
SNMPv2-MIB::sysContact.0 = STRING: default_user@contact.domain
SNMPv2-MIB::sysName.0 = STRING: airport-express
SNMPv2-MIB::sysLocation.0 = STRING: defaultlocation
SNMPv2-MIB::sysServices.0 = INTEGER: 12
SNMPv2-MIB::sysORLastChange.0 = Timeticks: (3) 0:00:00.03
SNMPv2-MIB::sysORID.1 = OID: SNMPv2-MIB::snmpMIB
SNMPv2-MIB::sysORID.2 = OID: TCP-MIB::tcpMIB
It seems to have racoon installed, pppoe.
PF is enabled by default:
airport-express# pfctl -s all
FILTER RULES:
block drop all
pass on lo0 all flags S/SA keep state
pass out proto tcp from any to any port = domain flags S/SA keep state
pass out proto udp from any to any port = domain keep state
pass out inet6 proto ipv6-icmp all icmp6-type neighbrsol keep state
pass out inet6 proto ipv6-icmp all icmp6-type routersol keep state
pass in inet6 proto ipv6-icmp all icmp6-type neighbradv keep state
pass in inet6 proto ipv6-icmp all icmp6-type routeradv keep state
pass out inet proto icmp all icmp-type echoreq keep state
No queue in use
Interesting huh?
I decided to build a Minimig – a clone of Amiga, it can act as Amiga 500, 500+ or 600, with up to 4MB total RAM.
The interesting thing is that it uses an actual 68000 CPU – clocked at 7 or 50MHz in Turbo mode.
Other proprietary Commodore chips are implemented in FPGA.
I also built an ARM controller board – which replaces the small PIC micro, serves as SD card interface and feeds the FPGA with initial bitstream.
I’ve also included 3 hardware mod’s – additional 2MB RAM (sitting on top of original chips), SD high speed interface and lastly – joint stereo/separate stereo switch.
This was my first time soldering such a fine pitch (and expensive) chip – wasn’t all that hard.
