[TangerineSDR] TangerineSDR Digest, Vol 31, Issue 1

Tue Oct 5 19:59:39 EDT 2021

I marked up the PDF to try to explain what I was seeing - hopefully it will
make more sense now. I realized another oddity exists in the description as
well; JMP2 is called out but does not seem to exist in the current
schematic. I'm guessing the description page was written for an earlier rev
that had a more limited set of address selections, and had JMP2 in the
circuit.

Bill.

On Sun, Oct 3, 2021 at 3:47 PM Julius Madey <hillfox at fairpoint.net> wrote:

> Bill,
> This is the i2c address space of the 9808 and RM3100 per the data
> sheets......0 is ground and 1 is Vdd
>
>
>
>
> I think you meant that JMP4 in the second column should be JMP1 rather
> than the other way round.  JMP4 is the shield ground.
>
> When the local board is plugged on the Pi 40 pin header as a PiHAT, A0 is
> pulled low, which limits the possible address space for the RM3100 on the
> local board to 0x20 and 0x22, and the local 9808 to 0x18, 0x1A, 0x1C and
> 0x1E.
>
> For the remote board, all addresses in the above table are
> available......except that used for the 9808 on the local board.  If no
> address jumpers are installed on the local board, then 9808 addresses 0x19
> through 0x1F are available at the remote.
>
> Note that no more than four RM3100s can be used on the same i2c bus ...
> expansion beyond that requires an i2c multiplexer like the TCA9548a which
> Dave Witten and I were considering for a test board for the RM3100 that
> would service some 32 RM3100s.
>
> CAUTION regarding the note under extended mode in the address tables and
> the use of multiple 9615 differential i2c drops on the CAT5 or CAT6 cable.
> Read the 9615 data sheet carefully on the subject of multiple drops ....
> intended for short (~ 3meter cable runs) at a 1MHz bus speed.  My testing
> to 400+ feet was with only a local and remote board at 100KHz bus speed
> which demonstrated well behaved transmission line behavior for the ~100ohm
> twisted pair lines in the cable with no reflections and no transient
> spikes.
>
> The 9615 data sheet example for multiple drops on the differential lines
> show NO termination resistances on the intermediate drops and only line
> terminations at the beginning and end 9615s.   I'm going to hazard a guess
> that you might be able to use 100 feet or so of cable with a couple of
> intermediate drops within 3 or 4 feet of the remote end and NO terminations
> on the 9615s on those boards but would have to actually scope test that to
> verify.
>
> The only multiple mag install on a single CAT cable I am aware of is the
> one I'm using here with two RM3100 remote boards within about 3 inches of
> one another connected only by ground, +3.3V, SDA and SCL  (eg i2c bus
> connections only).
>
> Regards,
> Jules-K2KGJ
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> On 10/2/2021 11:36 PM, Bill Owens wrote:
>
> I did get the email - thank you! I looked through the info on the second
> page of the PDF and I have some questions, but it does confirm that there
> are options for as many as four sensor boards, which fits with what I was
> considering.
>
> I think the box below the I2C table is wrong for the MCP9808; the
> addresses should be 0x1E and 0x1F per the table, and the callout in the
> schematic. It also mentions JMP1 in the second column, I think that should
> be JMP4.
>
> I also noted that JMP4 is described as being set only on the local board
> in most locations, but shown as "Placed" on the remote board in the NORMAL
> MODE and EXTENDED MODE boxes.
>
> I'm curious about whether there's a plan for deploying multiple sensors;
> one of the notes implies that, without giving any other details. Would it
> be a star configuration with the Pi at the center, or a daisy-chain using
> both the RJ45 and J10 for the boards in the middle?
>
> Thanks,
> Bill N2RKL
>
> On Sat, Oct 2, 2021 at 1:54 PM Julius Madey via TangerineSDR <
> tangerinesdr at lists.tapr.org> wrote:
>
>> I answered Bill a few days ago....perhaps he didn't receive the email.
>> I forwarded the latest schematic and layout for the board which has a
>> section on setting i2c addresses.  Perhaps Scotty can update that further.
>> Jules-K2KGJ
>>
>>
>> On 10/2/2021 12:00 PM, tangerinesdr-request at lists.tapr.org wrote:
>>
>> Send TangerineSDR mailing list submissions to
>> 	tangerinesdr at lists.tapr.org
>>
>> To subscribe or unsubscribe via the World Wide Web, visit
>> 	http://lists.tapr.org/mailman/listinfo/tangerinesdr_lists.tapr.org
>> or, via email, send a message with subject or body 'help' to
>> 	tangerinesdr-request at lists.tapr.org
>>
>> You can reach the person managing the list at
>> 	tangerinesdr-owner at lists.tapr.org
>>
>> When replying, please edit your Subject line so it is more specific
>> than "Re: Contents of TangerineSDR digest..."
>>
>>
>> Today's Topics:
>>
>>    1. FW: [HamSCI] Two questions about the new TAPR magnetometer
>>       board (Dr. Nathaniel A. Frissell Ph.D.)
>>
>>
>> ----------------------------------------------------------------------
>>
>> Message: 1
>> Date: Fri, 1 Oct 2021 16:22:25 +0000
>> From: "Dr. Nathaniel A. Frissell Ph.D."
>> 	<nathaniel.frissell at scranton.edu> <nathaniel.frissell at scranton.edu>
>> To: "tangerinesdr at lists.tapr.org" <tangerinesdr at lists.tapr.org> <tangerinesdr at lists.tapr.org> <tangerinesdr at lists.tapr.org>
>> Subject: [TangerineSDR] FW: [HamSCI] Two questions about the new TAPR
>> 	magnetometer board
>> Message-ID:
>> 	<BLAPR03MB5540044997C2145BB6D46D2AF2AB9 at BLAPR03MB5540.namprd03.prod.outlook.com> <BLAPR03MB5540044997C2145BB6D46D2AF2AB9 at BLAPR03MB5540.namprd03.prod.outlook.com>
>> 	
>> Content-Type: text/plain; charset="us-ascii"
>>
>> Hi,
>>
>> I'm sending these questions from Bill N2RKL to the TangerineSDR list. They were originally posted on the HamSCI list.
>>
>> 73 Nathaniel
>>
>> From: hamsci at googlegroups.com <hamsci at googlegroups.com> <hamsci at googlegroups.com> On Behalf Of Bill Owens
>> Sent: Thursday, September 30, 2021 9:22 AM
>> To: HamSCI <hamsci at googlegroups.com> <hamsci at googlegroups.com>
>> Subject: [HamSCI] Two questions about the new TAPR magnetometer board
>>
>> I've listened to the last couple Zoom sessions and also found the layout pictures that Scotty showed a few weeks ago, but I haven't been able to work out answers for two questions:
>>
>>  - How many I2C addresses can be set for the magnetometer and the temperature sensor on each board?
>>  - Are the RM3100 components soldered on the boards, or perhaps on half of them? It looks like there are options for SMT header sockets, and for the components themselves.
>>
>> Thanks,
>> Bill N2RKL
>> --
>> Please follow the HamSCI Community Participation Guidelines at http://hamsci.org/hamsci-community-participation-guidelines<https://nam10.safelinks.protection.outlook.com/?url=http%3A%2F%2Fhamsci.org%2Fhamsci-community-participation-guidelines&data=04%7C01%7Cnathaniel.frissell%40scranton.edu%7Cb1641a76631b43daaadf08d9841553f1%7Ca8edc49a41f14c699768a7f6d7c3b8c3%7C0%7C0%7C637686049874237358%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=TPhDGbKvqiaOqA6FWYIaFntFkhAhTXHTzabPU8gzYMk%3D&reserved=0> <https://nam10.safelinks.protection.outlook.com/?url=http%3A%2F%2Fhamsci.org%2Fhamsci-community-participation-guidelines&data=04%7C01%7Cnathaniel.frissell%40scranton.edu%7Cb1641a76631b43daaadf08d9841553f1%7Ca8edc49a41f14c699768a7f6d7c3b8c3%7C0%7C0%7C637686049874237358%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=TPhDGbKvqiaOqA6FWYIaFntFkhAhTXHTzabPU8gzYMk%3D&reserved=0>.
>> ---
>> You received this message because you are subscribed to the Google Groups "HamSCI" group.
>> To unsubscribe from this group and stop receiving emails from it, send an email to hamsci+unsubscribe at googlegroups.com<mailto:hamsci+unsubscribe at googlegroups.com> <hamsci+unsubscribe at googlegroups.com>.
>> To view this discussion on the web visit https://groups.google.com/d/msgid/hamsci/ccea68f6-68a7-4553-83f7-803cb0370fa8n%40googlegroups.com<https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgroups.google.com%2Fd%2Fmsgid%2Fhamsci%2Fccea68f6-68a7-4553-83f7-803cb0370fa8n%2540googlegroups.com%3Futm_medium%3Demail%26utm_source%3Dfooter&data=04%7C01%7Cnathaniel.frissell%40scranton.edu%7Cb1641a76631b43daaadf08d9841553f1%7Ca8edc49a41f14c699768a7f6d7c3b8c3%7C0%7C0%7C637686049874247307%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=xxd2yhh%2FJMcfbszeF0tqqlhO29Ff2wu360iaFlx8UcE%3D&reserved=0> <https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgroups.google.com%2Fd%2Fmsgid%2Fhamsci%2Fccea68f6-68a7-4553-83f7-803cb0370fa8n%2540googlegroups.com%3Futm_medium%3Demail%26utm_source%3Dfooter&data=04%7C01%7Cnathaniel.frissell%40scranton.edu%7Cb1641a76631b43daaadf08d9841553f1%7Ca8edc49a41f14c699768a7f6d7c3b8c3%7C0%7C0%7C637686049874247307%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=xxd2yhh%2FJMcfbszeF0tqqlhO29Ff2wu360iaFlx8UcE%3D&reserved=0>.
>> -------------- next part --------------
>> An HTML attachment was scrubbed...
>> URL: <http://lists.tapr.org/pipermail/tangerinesdr_lists.tapr.org/attachments/20211001/83308c2b/attachment-0001.html> <http://lists.tapr.org/pipermail/tangerinesdr_lists.tapr.org/attachments/20211001/83308c2b/attachment-0001.html>
>>
>> ------------------------------
>>
>> Subject: Digest Footer
>>
>> TangerineSDR mailing listTangerineSDR at lists.tapr.orghttp://lists.tapr.org/mailman/listinfo/tangerinesdr_lists.tapr.org
>>
>>
>> ------------------------------
>>
>> End of TangerineSDR Digest, Vol 31, Issue 1
>> *******************************************
>>
>>
>>
>> --
>> TangerineSDR mailing list
>> TangerineSDR at lists.tapr.org
>> http://lists.tapr.org/mailman/listinfo/tangerinesdr_lists.tapr.org
>>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.tapr.org/pipermail/tangerinesdr_lists.tapr.org/attachments/20211005/7877d295/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: ogejejdhhbknfbhc.png
Type: image/png
Size: 16561 bytes
Desc: not available
URL: <http://lists.tapr.org/pipermail/tangerinesdr_lists.tapr.org/attachments/20211005/7877d295/attachment-0002.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Screen Shot 2021-10-05 at 7.58.14 PM.png
Type: image/png
Size: 297997 bytes
Desc: not available
URL: <http://lists.tapr.org/pipermail/tangerinesdr_lists.tapr.org/attachments/20211005/7877d295/attachment-0003.png>