Expansion Board Suggestions

[bmarkus]

I would love a Tilt and Vibration Sensor to wake up device from deep sleep when moved, like

https://signalquest.com/product/components/sq-sen-200/

or similar. I'm using it in low power LoRa trackers and love it.

[jcaron]

If we are on the topic of what should be changed in future revisions of the expansion boards...

• why is the JST battery connector on the side, next to the USB port? If you have a battery connected there, that makes the USB connector impractical in a case. Actually, it would probably be even better if the USB connector was “sticking out” a bit more so it could get through a case wall.

  It also makes it impractical to disconnect/reconnect the battery while in a case. Having the connector on the other side (on the “right” if you have the USB connector “up”), or vertical rather than horizontal would probably be a lot more useful

• the screw holes on the Pysense are partially covered by the module, which prevents mouting “from the top” in case you have a battery underneath.

• adding a power input other than the USB port (but which can still be used to charge the battery) could be useful.

• I believe there’s quite some demand for a board that would include the necessary hardware to connect a solar panel and a battery

• a board that includes the usb + battery connectors (+possibly solar panel connector), a button and just a few I/O pins, but with a smaller form factor than the expansion board would probably be much appreciated.

• having compatible cases, or pointers to existing cases with compatible screw holes / PCB guides would be quite useful. This is quite a complex quest in my experience (but if someone has suggestions for a case which would be practical for Pysense + LoPy + battery + a PIR sensor, please let me know!).

[brotherdust]

@seb said in Expansion Board Suggestions:

Hi,

Once again thanks for the feedback, so here is what I was able to distil from your message

• Block diagrams for all expansion boards - This is certainly something we can add, and will be added to our todo list for the documentation refresh.
• Example code - I agree there is a lot of room for improvement here especially around the pytrack/pysense. Once the getting started section of the documentation has been update, checking/fixing/improving all of our examples will be my next task.
• UART & 1PPS pins - I have passed this on to the hardware team, if there is a new hardware revision of the Pytrack they will consider this

Thanks for wading through my rant and finding the key points. Yes, you've got it right. =) All the previous suggestions still apply, though!

[brotherdust]

@jcaron RE: cases, I wonder if the right solution for you would be to use a 3d-printer or outsource it to someone who can print it for you. The geometry of such a case would be simple. You'd need to specify UV-stabilized plastic if your application is outdoor. Hopefully that helps.

[crumble]

@jcaron said in Expansion Board Suggestions:

• why is the JST battery connector on the side, next to the USB port?

I don't like the JST connector. I have not found huge one cell LiPos with this plug in my local electronic store. Some additional solder points will be fine.

[fsergeys]

If I can add to pytrack features

• gyroscope and compass (very much needed :-) )
• Integrated battery gas gauge

[gregcope]

@brotherdust
+1 to a u.fl
+1 to switchable inputs
+1 to a different GNS chip Neo8 a good choice

[crumble]

@gregcope said in Expansion Board Suggestions:

+1 to a different GNS chip Neo8 a good choice

Can you explain why? Power consumtion? Faster syncs? Cool features like events for geo fencing?

+1 for a plug to connect an external GPS-Antenna.

[gregcope]

@crumble

• Its well known so lots of working examples

• Has an LNA i believe so should have better reception

• The one i have is much faster to fix, althought this could be antenna related

[nathanh]

@gregcope said in Expansion Board Suggestions:

@crumble

• Its well known so lots of working examples

• Has an LNA i believe so should have better reception

• The one i have is much faster to fix, althought this could be antenna related

Yup, the ublox is fantastic. I originally purchased a quectel to have the GPS type as the one Pycom uses as I thought this would make integration much easier and found nothing but issues with it. I purchased a ublox later and found it much more of a polished product. I had both units next to each other on the same breadboard, powered from the same FiPy and the ublox, without fail, would get a fix before the quectel. Sometimes the difference was 10-15 seconds (ublox) vs 15 minutes (quectel). From testing it seems the quectel don't actually save their ephemeris data completely like they claim.

But the huge benefit I found from the ublox is their propriety protocol which is much cleaner and efficient than parsing NMEA strings and I can poll rather than reading a stream!! So in one poll command/response I can get Lat/Lon, full date and time, velocity, direction and accuracy/error. To do the same parsing NMEA strings takes at least 3 different string types. Also since I am reading a single response that I can parse I don't need to use the minigps library which again saves a huge amount of memory.

[Charly86]

May be too late but for future
please expose 3 more pads so we can use then to solder other battery connector (even with wire)

• VBat

• GND (we have plenty so not mandatory)

• TS pin of the battery charger, my battery have NTC on then (3 pins), charger IC can manage it but can't use this feature just because the pin is not exposed on PCB.

• Place a PTH resistor footprint to change charging current so we can set it to another value

• Another user button would be fine ;-)

[Charly86]

@brotherdust any chance you share the pin pad mapping on the bottom (at least RX/TX) ?