MOD-1016 AS3935 based lightning and storm sensor

3 posts
by RiccardoMoretti » Fri Sep 06, 2013 12:35 pm
I purchased a MOD-1016 AS3935 based lightning detector,
and while I wait for it to arrive I'm doing some homework.

Looking at the schematic there are 2x 10K pullup resistors on the break out kit R1 & R2
and in the documentation it states that if the micro controller or I2c bus has already pullup resistors then R1 & R2 should be removed.

My question is simple does the Pi have built in Pullup resistors on the I2C bus?
and if it does should remove these two resistors on the breakout kit?
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by Burngate » Fri Sep 06, 2013 4:30 pm
Schematic of the Pi shows 1k8 pull-ups on GPIO pins 3 & 5

The 10k pull-ups on board will make little difference in parallel with those 1k8 ones, so remove or not as your fancy takes you!

Be aware the Pi's GPIOs aren't 5v tolerant, so stick to 3v3 for Vcc
Wyszkowski's Second Law: Anything can be made to work if you fiddle with it long enough.
Brain surgery is easier than psychoanalysis
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by RiccardoMoretti » Sun Sep 29, 2013 4:15 pm
Ok Progress, my breakout kit has arrived, and I think I'm stuck,
dont know if a kind person can have a look at this for me

AS3935 Pin Raspberry Pi Pin
4 (GND) 25 (Ground)
5 (VDD) 1 (3v3 Power)
10 (IRQ) 17 (GPIO)
11 (I2CL) 5 (SCL)
13 (I2CD) 3 (SDA)

Looking at the table pin 25/1/5/3 all map to the actual P1 Header pins, what's confusing is the reference to "17 (GPIO)" pin 17 is actually 3.3volts and I'm sure should read 11 (GPIO 17)?
What do you think?
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