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STM32-DVM RSSI

Posted: Sat May 19, 2018 5:17 pm
by VA7WPN
What... have I done wrong here?

received RF end of transmission, 1.9 seconds, BER: 0.0%, RSSI: -141/-141/-141 dBm

Re: STM32-DVM RSSI

Posted: Sat May 19, 2018 7:03 pm
by MW0MWZ
/usr/local/etc/RSSI.dat is not populated would be my guess.

There is an editor for that in the expert section.

Re: STM32-DVM RSSI

Posted: Sat May 19, 2018 7:56 pm
by VA7WPN
This is what is in that file :

# This file maps the raw RSSI values to dBm values to send to the DMR network. A number of data
# points should be entered and the software will use those to work out the in-between values.
#
# The format of the file is:
# Raw RSSI Value dBm Value
#
#
# RSSI Default Values for MMDVM_HS
#
43 -43
53 -53
63 -63
73 -73
83 -83
93 -93
99 -99
105 -105
111 -111
117 -117
123 -123
129 -129
135 -135
141 -141

Here is a snipet of my traffic. RSSI shows as S1

Capture.PNG
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Re: STM32-DVM RSSI

Posted: Sat May 19, 2018 8:11 pm
by VA7WPN
I have updated my RSSI file as below according to http://va2dg.ca/wp/wp-content/uploads/2 ... -board.pdf:

# This file maps the raw RSSI values to dBm values to send to the DMR network. A number of data
# points should be entered and the software will use those to work out the in-between values.
#
# The format of the file is:
# Raw RSSI Value dBm Value
#
#
# RSSI Default Values for MMDVM_HS
#
# 43 -43
# 53 -53
# 63 -63
# 73 -73
# 83 -83
# 93 -93
# 99 -99
# 105 -105
# 111 -111
# 117 -117
# 123 -123
# 129 -129
# 135 -135
# 141 -141
346 -137
381 -124
443 -115
485 -110
560 -100
629 -90
698 -80
740 -75
787 -70
819 -65
830 -60
832 -55

And now My Dashboard says :

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Re: STM32-DVM RSSI

Posted: Mon May 21, 2018 7:46 pm
by MW0MWZ
RSSI values depend on the radio - the stock values are there for MMDVM_HS units that support RSSI, if you use anything else, yes you may well need to tune it...

Re: STM32-DVM RSSI

Posted: Tue Jun 12, 2018 4:37 am
by VA7WPN
How do I go about testing and Determining the RSSI Values for my specific radios?

Does Motorola offer this info? or do I need to use a Service monitor or Spectrum Analyzer to figure this out?

thanks

Re: STM32-DVM RSSI

Posted: Tue Jun 12, 2018 6:19 pm
by K7AZ
I too would like to have a procedure to obtain values to enter in the look up table.
I have access to an HP service monitor if that helps. I realize this will be a non-linear data table.
To further compound things, Repeater-Builder V3 board has a pot to adjust the RSSI voltage.

Many thanks in advance for help with this.

73
Chris K7AZ

Re: STM32-DVM RSSI

Posted: Wed Jun 27, 2018 7:04 am
by ZL2ARL
Definitely following this thread!

Re: STM32-DVM RSSI

Posted: Fri May 24, 2019 1:00 pm
by M6NBP
K7AZ wrote:
Tue Jun 12, 2018 6:19 pm
I too would like to have a procedure to obtain values to enter in the look up table.
I have access to an HP service monitor if that helps. I realize this will be a non-linear data table.
To further compound things, Repeater-Builder V3 board has a pot to adjust the RSSI voltage.

Many thanks in advance for help with this.

73
Chris K7AZ

Did you ever find out how to set the Repeater-Builder V3 board RSSI voltage pot?

Many thanks

Norman

Re: STM32-DVM RSSI

Posted: Wed Aug 21, 2019 1:46 am
by VE1AIC
Lookup mmdvmcal in RSSI mode (S/s).
It's included in Pi-Star.
It will give you the RSSI number for a given RF input.

Just hook your Sig Gen to the RX and adjust output in 10db steps from no signal (< -130dbm)
until it saturates maybe around -50dbm.

Enter those numbers in RSSI.dat.

If someone has already done this for your model or radio it's probably close enough but easy to check.
Look at the mmdvmcal number with no signal, then TX with an HT nearby and compare that to the upper end.

73, Ron
VE1AIC