TPL5110 to cycle only once when button is pressed

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iesre
 
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Re: TPL5110 to cycle only once when button is pressed

Post by iesre »

I have had various degrees of success with using these TPL5110 timers. I've found that the tiny potentiometer used to adjust the cycle time is VERY sensitive. It appears to fail sometimes in cold weather and the contacts may be intermittent. (I'm using it in an outdoor weather station.) It would be a good idea to have a way to replace the potentiometer with a fixed resistor, assuming that you don't need to change the cycle time regularly. The online description says the cycle time is "adjustable by potentiometer or resistor..." How do you bypass the potentiometer. What is the "trim enable" pad on the back of the board used for?
The corresponding item from SparkFun has dip switch-selectable resistances, which might be more reliable.

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iesre
 
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Re: TPL5110 to cycle only once when button is pressed

Post by iesre »

Regarding my previous comments about the TPL5110 board sometimes refusing to cycle, refer to the SparkFun documentation about their version of this device. That documentation states that with some microcontrollers it may be necessary to connect a 10 K pull-down resistor from the Done pin to ground. I have a battery-powered Pro Mini system running on my desk right now that refused to cycle (with the delay resistance set to about 29 K) without a pull-down resistor, but appears to be working OK now with that resistor. Comments? Thoughts?

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