2022-07-19 at 3:40 PM #17159
What jumper settings are required to operate a Digi XBee LTE-M on Mayfly v1.x? I’ve read the jumper settings page, which details what each jumper does, including the Bee socket-related ones, but without being familiar with the electrical requirements of the Digi, I’m unclear what needs to change. I have a likely-failed Mayfly v0.5b, which I’d like to replace with a v1.1, but retain the still-working Digi modem.
2022-07-19 at 8:01 PM #17160Shannon HicksModerator
The purpose of the now-discontinued “EnviroDIY LTEbee Adapter” was to allow people to use the Digi brand LTE cellular module with the Mayfly v0.5 boards by doing 3 main thing: providing sufficient power (current) to the cell module, connecting pin 13 of the Digi board to pin 12 of the Mayfly bee socket, and giving the user some LEDs to show status of the module (because the Digi boards have no lights themselves). When I designed the Mayfly 1.0 boards last year, I included all those features into the Mayfly’s new design, so people can now use a Digi board without the need for the bulky EnviroDIY adapter board in between.
The Mayfly v1.0 and v1.1 boards have sufficient power on the bee socket now (1 Amp dedicated solely to the bee socket) so they no longer need that little jumper wire to connect between the Lipo socket and the cell module like on previous versions. On Mayfly v1.0 and v1.1, the default setting is for the bee socket to be powered only when pin 18 is high. This action is dictated by SJ18, so leave it as it is (set to D18) and make sure your Arduino sketch code has modemVccpin set to 18.
Then, to change the bee status pin from the usual Bee pin 12 to Bee pin 13, move the solder blob on SJ19 from 12 to 13. This status pin is monitored by Mayfly pin D19, so in your code, make sure modemStatusPin is set to 19.
Then if you want to see when the modem is turned on (white LED) and it network status (blue LED – it’ll blink or be solid based on whether it is actively connected or not) put a small blob of solder on jumpers SJ16 and SJ17.
That’s all the changes you need to make to the v1.0 or v1.1 board in order to use a Digi cell board with the Mayfly. If you ever decide to use an EnviroDIY LTE cell board (with the SIM7080 module on it), you’ll need to put solder jumper SJ19 back in its original position. It’s fine to leave the Mayfly’s LEDs jumpered with the SIM7080 cell boards, but it’s kind of unnecessary since there are 2 LEDs already included on the cell board, making them redundant.
If you’re using the ModularSensors example sketch that’s currently on Github called DRWI_DigiLTE, note that it’s written for the v0.5 boards, so you’ll need to make the changes mentioned above for the modemVccPin (set it to 18 instead of -2) and then you also need to change the modemResetPin from 20 to A5. Previous versions of the Mayfly had the modem reset pin wired to Mayfly D20, but all new versions of the Mayfly have the modem reset connected to A5.
That should be everything you need to do in order to get the Digi cell boards to operate on the Mayfly v1.0 or v1.1 boards. Give that a try and let us know if it’s successful.
2022-07-20 at 10:56 AM #17161
Thanks for this excellent detail.
So we could continue to use the LTEBee adapter with the Digi modem on a v1.1 Mayfly, which would retain the functionality of the white and blue modem status LEDs, and would connect the Bee socket’s pin to the proper status pin on the Digi (without need to modify SJ19), and we would not need the power jumper to the Lipo socket. Is that correct?
2022-07-20 at 11:42 AM #17162Shannon HicksModerator
No, the old LTEbee Adapter should not be used with a Mayfly v1.x board. You simply plug the Digi board directly into the Mayfly v1.x board with no adapter at all. Make the changes to the jumpers I mentioned above and you’ll enable the white and blue status LEDs that are built into the new Mayfly boards. The only thing missing is the orange RSSI light, but it didn’t always work right, plus that parameter is reported digitally and is captured by your sketch and will be transmitted to MMW anyway.
2022-07-20 at 6:24 PM #17163
OK, got it, thanks.
I’ve made the hardware and software modifications you recommended and all seems to work perfectly.
2022-07-22 at 10:06 PM #17164neilh20Participant
@mbarney on Mayfly 1.1 I connect SJ17 – that enables the Blue Network Status LED, and indicates the progress of the LTE-CATME connection. Off – no connection, ( I think) ON – attempting connection, FLASHING – connecting
For Mayfly1.1 I also
Solder SJ15 – assumes 4400mA hr battery, and allows 1A charge, but that depends on solar panel.
J27 desolder A6-Vin , solder A6-LiPo ~ more accurate Vbat reading.
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