From: the s. e. <sui...@gm...> - 2013-03-28 22:02:46
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So I found and removed a pair of 1.5k pull up resistors for the I2C-3 lines on the Tobi, which helped. It now takes 3.7mA to drive the lines low instead of 4.7mA. The MSP430 is able to get the line lower than before, low enough now for the gumstix to register the clock stretch and stop pumping out data, but not low enough for it to register the ack. The weird thing is that with these resistors on the Tobi gone, I'm measuring no significant resistance between the I2C lines and 1.8v, yet once the gumstix is powered up the lines are being pulled high so hard that it takes 3.7mA to drive them to 0 (the equivalent of 490 ohm pull ups). I really wish Gumstix would release the schematics of their COMs so I could see what's going on here. -- View this message in context: http://gumstix.8.n6.nabble.com/overo-I2C-pull-up-resistors-tp4967078p4967079.html Sent from the Gumstix mailing list archive at Nabble.com. |