so everything was working and then I added a photo-resistor to the Asset Tracker board and since then I have lost communication with it. GPS will blink and then find fix (with external antennae) but I do not receive data anymore.
Tried with another shield (same electron) and all is fine. I get about 3Volt from D6, so I assume I somehow wrecked the connection to serial.1 ?
If I ask Serial.1 for a simple “hello” I don’t get a print.
Is there any way to fix it? Could I use one of the other ports? I have removed all the offending parts but the problem persists
3V on D6 seems to shut down the GPS module. At least that’s what it should do.
Letting go of D6 (e.g. via INPUT mode) or setting it HIGH will cause the module to be powered down.
thanks @ScruffR, I guess the correct way would be to say D6 is sinking 3.3V… which is consistent with the functioning shield…
I connected the photo-resistor from A5 to the 3.3 V rail adding a 1k resistor to GRD (I realise it would be better to rather power the sensor through a pin), soldering it onto the perfboard part of the shield.
with a Voltmeter on the D6 pin, the fix LED and the fact that it all works when i plug it into a working shield…guess that doesn’t rule out a fault in the GPS, but then should I not be able to print a “hello” over the serial1? … its a V1
I see.
Normally voltage measurements are referenced to GND (D6 - GND will read 0V).
You measured the voltage drop across the pull-up resistor - hence the confusion