Author Topic: inAir9, is J1 always here ?  (Read 1896 times)

fletort

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inAir9, is J1 always here ?
« on: September 29, 2015, 03:23:33 PM »
On the web page we can read :
Solder Jumper J1 & RF Switch
Note that solder jumper J1 at the back of the board has to be made to apply power to the RF Switch. Making jumper J1 applies permanent 3.3V power to the RF Switch (U5 in schematic = PE4259).

But J1 is not describe on the schematic and does not seem to be on the pcb.

J1 is no more here ?

modtro2

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Re: inAir9, is J1 always here ?
« Reply #1 on: October 05, 2015, 03:41:49 PM »
At delivery, the RF Switch is always made.

  • On the newer boards, there is a solder jumper on the back of the board. It is clearly marked J1, and is made by default. So, by default, jumper J1 is made, and it powers the RF switch.
  • The older boards don't have a solder jumper(J1) for the RF switch, and it is always powered.

The RF Switch was added to newer boards for applications that need to go into very low power mode. The RF switch only consumes a couple of uA power, but for very low power applications, that is not desirable. So, to save the maximum amount of power, solder jumper J1 can be opened, allowing the RF switch only to be powered when transmitting or receiving.



mayer

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Re: inAir9, is J1 always here ?
« Reply #2 on: October 07, 2015, 04:21:14 AM »
On the two inAir9B I got recently the solder jumper J1 is not made by default!

modtro2

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Re: inAir9, is J1 always here ?
« Reply #3 on: October 08, 2015, 02:44:12 PM »
Very sorry about this. Not sure how that slipped though our test. All inAir modules are connected to a tested that tests the transmit and receive signal strength. It will not pass if this jumper is not made. Maybe you got one of the very first modules when we released this board - before we had our current tester?

mayer

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Re: inAir9, is J1 always here ?
« Reply #4 on: October 09, 2015, 01:01:14 AM »
It got shipped 23/7 this year.
Just to avoid misunderstandings: The little solder pads on the back of the board are there, but they were not short-circuited. If I understand you correctly this must imply that the boards were not tested? So maybe there is a connection to this here: http://forum.modtronix.com/index.php?topic=2229.msg10166#msg10166 ?
« Last Edit: October 09, 2015, 01:07:26 AM by mayer »

modtro2

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Re: inAir9, is J1 always here ?
« Reply #5 on: October 12, 2015, 11:08:05 PM »