Dear all,
i have the configuration as shown in the attachment.
i connected an external 5v to the GSM shield to prevent short burst. For my temperature sensors, i tested with TMP36 and LM35 (they are powered by a separated power supply; A 220AC to 4.9DC), they give me the same problem which is the analogRead() returns a random number, of which i see 1023 and 0 coming out quite a lot. Is there something wrong with the hardware connection? Please help me a little bit. Thank you in advance!
Guys! Now the problem shall reduce to the voltage supplied to the temperature sensor, when i am powering my LM35 sensor from the 5v Supply on the Arduino UNO, everything works fine. But if i am powering it from a separated power supply, things gone wrong terribly? Anyone got a clue for this?
camac:
I believe no sir! Which ground on the arduino shall i connect
It may be the cause of it! Thank you for replying!
Any one of the ground pins on the arduino will do. An UNO () has 3 of them (marked GND), 2 next to the 5Vand one the other side next to AREF. Your board may be different but you should get the idea