Got my #twatch, and was quite excited to hook it up. Went and got a universal AC/DC adapter (Philips is a reputable brand, right?), set it for 6 volts, and plugged it in. No joy. So, I got out the multimeter to check things, and found that when set at 6 volts it was, in fact, spitting out 9, and when set to 7.5 it was outputing 11. Tested another AC/DC adapter, just to be sure it wasn't my multimeter - it's reading correctly.
So, given that I probably applied too much voltage to the #twatch, is there any way to repair it? I get no ethernet lights, no lcd display. Is it cooked?
Seeing higher readings on power adapters isn't all that unusual depending on how the output is regulated. Your measured voltages are around root2 times bigger than what your expecting... I wouldn't mind betting that if you put a load on that supply you'll see it come back down to where (you think) it should be. If you put a scope on it you'll probably see probably see a little ripple on the output too.
Either way, I dont think this is the problem of why your twatch isn't working since it has its own built in regulators anyway which should be able to handle more than 11V as an input. The more likely options are that either your polarity is wrong (Im assuming the adapter had a DC output), or your twatch was DOA, or maybe it's in a BL mode (although I'd expext to see active ethernet lights anyway if this was the case)?
Hi all,
Same problem for me. Tried two wall warts, one 6.5 VDC, 500 mA, the other 7.5 VDC, 350 mA. I get nothing on the LCD with either.
I tried fiddling with the small brightness pot on the board, no joy.
I'm going to try some different settings for my DHCP server, but I doubt that is what's keeping it from just "lighting up."
Joe
Ok, so that's good to know. Tried it again, and gave it a little more time to get rolling - and now it's working! Well, mostly. LCD backlight isn't lighting, but the contrast adjustment is working. So, it's mostly good.
Will do some reading, see if I'm missing something on the back light. Any suggestions in the mean time?
Sweet! Found the post about the backlight and the python script, and now it's all working perfectly! Thanks! (though now I feel kinda silly....)
Well, I'm giving up on this one. I get no signs of life from it at all. Even nothing from the ethernet connector LED's. I sent a note requesting return shipping instructions to Seeed today, awaiting reply. Anyone tried this; any suggestions?
Thanks!
Joe Henley
Hi Joe,
Have you tried to do a firmware update? The latest firmware has the backlight enabled, and another user reported their #twatch started working after upgrading to the latest firmware.
There's a bunch of links to updated firmware and instructions in the firmware section of the 'manual' page:
http://dangerousprototypes.com/twatch-manual/ (http://dangerousprototypes.com/twatch-manual/)
Joe,
You may need to put a jumper on GRN & PDG.. I had to do that, mine appeared to have been shipped in "bootloader", maybe yours did two.
Hi all,
Sorry for the delay in responding; things got a bit hectic in my work for awhile.
After more testing, I found the problem was with my power supplies. One dead, the other with a negative center pin. My bad, I assumed all wall warts were positive center pin. So now I have a new one; 7.5 VDC, 800 mA, center positive.
With the new power supply I got my dhcp server to connect and got the MAC address from my syslog (running Linux); then was able to ping it; then ran the python script to turn on the back light. After adjusting the back light pot, it works fine.
Next (probably after the holidays) I'll upload the new firmware (to get the back light on at start up) and then go from there.
Thanks for all the help and suggestions.
Joe Henley
Since I'm the one who started this thread, I figured I'd add a link to some info about wall warts: http://www.sparkfun.com/commerce/tutorial_info.php?tutorials_id=103 (http://http://www.sparkfun.com/commerce/tutorial_info.php?tutorials_id=103)