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I am trying to run a Maxim DS1077 programmable oscillator through the I2C bus from an Arduino Uno development platform. I am able to run the oscillator at the different pre-scaler values 1,2,4, and 8. My oscilloscope shows that the changes in Out 1 are appropriate. However, I cannot set the divider DIV register. It always seems to be set to N=1, i.e. it is as if the divider is not in there at all. I set the MUX bit for activating the divider correctly - tride both settings etc...but to no avail. Hardware set-up: both control ports are tied to GND, the serial communication lines are tied to 5V via 3.9kOhm, and I have 0.1 and 0.01uF between GND and Vcc. The serial lines are connected to the Arduino's analog ports 4 and 5, and I am using the wire library. I think the fact that I can set the prescaler shows that the I2C is not the issue...any tips would be appreciated! Thanks!

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  • \$\begingroup\$ A quick guess - what have you got the DIV1 bit in the MUX register set to? In the datasheet it says if this bit is set it will bypass the DIV register, routing the clock straight to OUT1. So it needs to be set to 0. It should be set to 0 as default so it's probably not this, but worth checking just in case.. \$\endgroup\$ – Oli Glaser Oct 23 '11 at 19:54
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I finally found out why I was not able to set the DIV register. I contacted Maxim and they told me that the MUX register bit for activating the DIV needs to be set AFTER setting the DIV. I had it in the opposite order in my initial program. After flipping the commands, everything worked!

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  • \$\begingroup\$ Could you post the code that you used to get this working? I'm also trying to get the DS1077 working properly in a microcontroller setup and am having an absolute pisser of a time! \$\endgroup\$ – Bitrex Oct 28 '11 at 4:49
  • \$\begingroup\$ I had exactly the same problem and the solution above worked INSTANTLY!!! Thanks!!!! \$\endgroup\$ – user61615 Dec 17 '14 at 10:24

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