I want to add external PA/LNA to boost the range for a pair of EVK1000 evaluation board. I read up that GPIO5 and GPIO6 can be used for this purpose and those are pins 33 and 30 respectively on DW1000. However, the EVK1000 document does not mention where these pins are or how to use them as GPIO. The only information I got was all GPIO pins are input by default and I need to set them to I/O pins every time the board is powered. Basically, where are the GPIO5 and GPIO6 ports on the EVK1000 evaluation board and can they be used as is without setting any switches. Any insight or help is appreciated.
Adding a PA will almost certainly result in an illegal system that exceeds the regulatory limits unless you are operating under some special rules (such as LAES in Europe).
There have been UWB modules advertised for sale in China which claimed to have LNA and PA. For example:
At -21 dBm/MHz, this is a full 20 dB over regulatory limits. I’ve never operated one of these kind of units, I suspect they don’t actually work all that well since what I can see from the datasheet doesn’t effuse me with a sense the design was done with the care that is really required.
[quote]
I read up that GPIO5 and GPIO6 can be used for this purpose and those are pins 33 and 30 respectively on DW1000. However, the EVK1000 document does not mention where these pins are or how to use them as GPIO. The only information I got was all GPIO pins are input by default and I need to set them to I/O pins every time the board is powered. Basically, where are the GPIO5 and GPIO6 ports on the EVK1000 evaluation board and can they be used as is without setting any switches. Any insight or help is appreciated.[/quote]
GPIO4 is EXTPA. This turns on the PA when the DW1000 is going to transmit. High = PA on. GPIO4 on the EVK1000 appears to not be connected to anything per the schematic.
GPIO5 is EXTTXE. You shouldn’t use this signal generally for PA since it doesn’t have anticipatory turn on and also has to be configured not to do fine grain sequencing. EXTPA is the better choice. GPIO5 on the EVK1000 goes to S3 DIP switch, which can be connected to R45.
GPIO6 is EXTRXE. This turns on the LNA when the DW1000 is in receive mode. High = LNA on. GPIO6 on the EVK1000 goes to S3 DIP switch, which can be connected to R46.
Note that GPIO5 and GPIO6 also control boot up SPI configuration. The SPI configuration can be programmed after boot up via SPI commands.
You will have to configure the GPIO for the EXTPA and EXTRXE functions on every power up.
You will need to control RF muxes to direct signal through the PA or LNA as appropriate.
You will have to build an RF section, which takes careful work, to implement the PA and LNA.
Mike Ciholas, President, Ciholas, Inc
3700 Bell Road, Newburgh, IN 47630 USA mikec@ciholas.com
+1 812 962 9408
Thanks for the reply Mike. Yeah, GPIO4 does not have a pin on EVK 1000 board and EXTPA cannot be used as a result. Also, GPIO5 and GPIO6 after getting connected to R45 and R46 do not have a trace to a pin. Basically, the EVK1000 board does not allow you to control an external PA/LNA even if you manage to add them because the pins that are supposed to control these external components are non existent on the board. You would have to make a custom board with DW1000 IC to utilize these GPIO pins. Am I correct?
Trying to hack on a PA/LNA system to an existing board is likely to produce results that are disappointing. It is hard enough to get something like that working with a well designed board, and trying to do it with spaghetti wires onto a second board is asking for trouble.
Mike Ciholas, President, Ciholas, Inc
3700 Bell Road, Newburgh, IN 47630 USA mikec@ciholas.com
+1 812 962 9408
Thanks a lot, Mike. I am thinking of looking into how to configure the board to use GPIO ports as outputs first. Then, I will see if I can use a DW1000 IC on a custom board. Thanks for the help.