Never mind, I overlooked the IN1-2 and IN-3-4 contacts. Awesome. Thank you so much!
What about the write protect and command pins? Everything in parallel?
Would this chip be an alternative for the ISL8499?
I generally look for my components at Farnell, don't have experience with digikey. I'm suspecting I'd have to pay customs to have it delivered to Belgium, so if I could find a good alternative at Farnell, that'd be easier 
EDIT: or this one? http://be.farnell.com/analog-devices/adg711brz-reel7/low-voltage-quad-spst-i-c/dp/2376782
That one supports a greater range of voltages (1.8V to 5.5V).
What would be the specifications to look for?
EDIT: I drew something up in Eagle. Does that seem correct? www.jensvanhoof.be/SDinterface.pdf
Earlier question - yes, the selection lines weren't shown. How you select is up to you - physical switch easiest as neither side has a control line you can program.
WP & CD - gonna have 8 IO, can switch those too. Or connect to both devices, the pins are typically just connected to Gnd via switch when the card is put in the socket.
The TI part is kind of high resistance - but the current being switched is low so you shouldn't get much voltage loss across the switch.
The Analog Devices, you need 3 (6 signals) or 4 (8 signals). The TI, you'd only need 2 total (8 signals).
Spec to look for is Low resistance, single power supply.
Not sure what part you used for the switch, but you have idea.
Hi again,
I purchased two of these chips:
http://be.farnell.com/texas-instruments/ts3a5018pwg4/switch-analog-spdt-quad-10r-smd/dp/1494943
I soldered them onto 2 breakout boards and tested the functionality. It works as expected if tested without any connection to the pins. You can see them integrated in the prototype (left and right from the 3.3V regulator):
The 6 contacts that I need to switch (4 over chip#1, 2 over chip#2), are brought to the 12 headers just to the right of the SubD9 connector. If I switch the power on like this, it works. Using a multimeter the upper row contacts connect to the bottom row, connecting all 6 lines.
I modified then the Sparkfun's board, cutting the 6 lines that run from its processor to the SD card, and bringing them to the headers on the board (T1-T6). I cut the original lines to those contacts, as I don't need them in their original function. In this picture you can see the modification (I put jumpers on the headers to test the board):
This works as well, as if there was no modification performed.
However, when I connect the 2 things, it doesn't work. The processor cannot read the SD card anymore. When I use my multimeter to 'bleep' the resistance between the two rows, it measures no connection. Like the switch(es) not performing their function anymore.
I don't really know what's going on. Any suggestions? None of the 6 voltages exceed V+ of the switch (3.3V).
Many of us cannot see the pics. Can you Modify your post, click Additional Options, Browse to your locally stored pics and Attach them?
Describe how you are controlling which switch is selected.
Many of us cannot see the pics. Can you Modify your post, click Additional Options, Browse to your locally stored pics and Attach them?
Done!
I've put the control lines of the 2 chips together and pull them up to V+ using a 10k resistor.
For the moment, I haven't hooked anything up to 'the other side'.
I already found 1 error: I didn't connect the ENABLE pins to GND, which explains why I couldn't 'bleep' the two rows when the WAV trigger was connected. That issue is solved now, all the connections are made when I look with my multimeter. The board still cannot read the SD card, though. On the CLK pin I see a clean 24Mhz carrier, just as I would without the modification.
I'm thinking that maybe the switch is not ready when the Sparkfun boots. De chips power supply is a 3.3V regulator that gets its input from the same power supply than the Sparkfun board. As the Sparkfun board only initialises its SD card during startup (it says in the manual that you need to power cycle the board each time the SD card is removed or re-inserted), would it be possible that the switch simply isn't ready fast enough? Does that make sense?
I don't switch speed would be the problem. Keep checking stuff.
Allright, I've got it working. Apparently the wire I used to connect the GND from the Sparkfun to my 3.3V regulator causes too much induction. If I put the oscilloscope's ground pin to one end of the wire and the probe to the other end, it doesn't seem clean at all. With a shorter cable it still looks dirty but it seems to pass the treshold, because it works.
I assume this problem will be solved in a later stage where everything will be neatly fitted on a proper PCB with a ground plane.
Next step: integrating the VUB300 on the other end of the chip. I'm sure you'll hear more problems soon
Thanks!
Woo hoo! Incremental progress - always a good start 8)
As expected, no luck so far with the VUB300. The problem is that I don't have a clue where to look.
Testing with a multimeter, D0-D1-D2-D3-CLK-CMD from the SD socket goes to the corresponding pins of the VUB300.
datasheet:
I did put all the components on page 10 around the chip and checked that there is 3.3V on pins 6,14,22 and 36.
I then cut a spare USB cable and attached this to the chip (D+, D- to pin 2 and 3, ground and shield together to the GND).
I'm not 100% sure about the USB pinout. On page 12 there is a description of a USB socket block. It seems that I have to put 5V on the vBUS pin (red wire on most USB cables), but since the USB port of the computer already supplies 5V, I thought I didn't have to connect this? I didn't put the components for that power supply either. I have put a 1µF elco between the GND and vBUS, although I don't run the vBUS pin anywhere on the chip.
Regarding USB+ and USB-, I've connected the wite wire in the USB cable to USB+ and the green one to USB-. I'm not sure if this is right.
Any suggestions?
I'm on the road all day. Try the forum.
Try the forum.
Will do Probably time to exit this topic anyway, We've drifted too far from the original question.
Thanks a lot in any case for all your contribution so far, I REALLY appreciate it!
Jens
Just curious did you ever get the VUB300 to work
http://openenergymonitor.org/emon/buildingblocks/usb-data-logger
many not be exactly what you are looking for.