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gsm and 3G shields tutorial :: f-AudioOutputs and c-uGSM / h-nanoGSM shields howto start tutorial



The purpose of this howto it is to show to you how to connect standard PC audio headsets (or equivalent audio periferals) port to your c-uGSM / h-nanoGSM shield.

 

You can use any capacitor microphone and 8-32ohm speaker with your c-uGSM / h-nanoGSM shields connecting (solder) them directly to the ANALOG AUDIO port (see into the page bottom), but now the new f-Audio adapter provides an elegant alternative.

 

What you will need

 

 

General considerations, conventions and references

Hardware references

GSM SHIELD (micro) c-uGSM v 1.13 top PCB view f-AudioOutputs v 1.02 top PCB view (w. installed audio sockets)
c-uGSM shield top   f-AudioOutputs adapter top

c-uGSM SHIELD ANALOG AUDIO INTERFACE
In the top PCB side, left hand, enumerating from left to right:
1. GND * GSM SHIELD DIGITAL GROUND
2. AGND * GSM SHIELD ANALOG GROUND

3. SPK+ * GSM SHIELD positive SPEAKER OUT
4. SPK- * GSM SHIELD negative SPEAKER OUT

5. MIC- * GSM SHIELD negative MICROPHONE IN
6. MIC+ * GSM SHIELD positive MICROPHONE IN

f-AudioOutputs adapter INTERFACE
In the left PCB side, enumerating from top to bottom:
1. GND * AUDIO ADAPTER DIGITAL GROUND
2. AGND * AUDIO ADAPTER ANALOG GROUND

3. SPKP * AUDIO ADAPTER positive SPEAKER OUT
4. SPKN * AUDIO ADAPTER negative SPEAKER OUT

5. MICN * AUDIO ADAPTER negative MICROPHONE IN
6. MICP * AUDIO ADAPTER positive MICROPHONE IN



GSM SHIELD (nano) h-nanoGSM v 1.08 top PCB view
h-nanoGSM shield top

h-nanoGSM SHIELD ANALOG AUDIO INTERFACE
In the top PCB side, left hand, enumerating from left to right:
1. GND * GSM SHIELD DIGITAL GROUND
2. AGND * GSM SHIELD ANALOG GROUND

3. SPK+ * GSM SHIELD positive SPEAKER OUT
4. SPK- * GSM SHIELD negative SPEAKER OUT

5. MIC- * GSM SHIELD negative MICROPHONE IN
6. MIC+ * GSM SHIELD positive MICROPHONE IN



f-AudioOutputs SPEAKER and MICROPHONE jacks howto wire

The f-AudioOutputs SPEAKER and MICROPHONE connections are full equivalent with the one implementated in the a-gsm shield.
f-AudioOutputs jacks wiring equivalence   a-gsm shield jacks wiring equivalence
SPEAKER and MICROPHONE connections should be done as in above-left picture.

HEALTH and SAFETY WARNING!
The c-uGSM shield have HIGH POWER AUDIO output (up to 870mW)! HEADSET USAGE CAN DAMAGE YOUR EARS (direct connection or trough f-AudioOutputs adapter)!




Brief c-uGSM direct (w/o f-AudioOutputs adapter)audio hardware connectivity description

1. c-uGSM SPK+ and SPK- goes to the speaker (respect the polarity),
2. c-uGSM MIC+ and MIC- goes to the microphone (respect the polarity),
3. c-uGSM GND and AGND must be connected together

The speaker must have 32 ohm (recommended) and the microphone must be capacitive.

For the h-nanoGSM shield, the very same wirring may be applied.

 

 

 

Dragos Iosub & itbrainpower.net team original how to.

 

 

 

 

document version 1.0 / 2016-08-22 © R&D Software Solutions srl