Remote Monitoring & Control

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Well, I am running out of time to complete this project.  All the usual excuses, out of town guests and other distractions.  I am going to do well just to finalize all the construction by next week.  I did a test print of the component mounting bracket (insert) for my case and I quickly realized that I was going to have issues with the assembly.

 

Issue #1 Battery Pack Connection

The battery pack that I'm using has 2 x AA batteries and a JST PH 2.0 connector.  The MKR 1300 has a terminal block interface for battery connection.  I could just cut the connector off the battery pack and use the bare wires, but I like the ability to quickly connect/disconnect the battery.  In lieu of a power switch I could just disconnect or reconnect the battery.  I decided to make an adapter with the mating JST PH 2.0 connector.  I wondered why they didn't just use that connector in the first place and I realized that standard 3.7V LiPo batteries use the same connector and their max voltage could damage the circuitry on the MKR 1300.  But this is a battery pack that is used with micro:bit boards which should have the same problem.  Then I noticed that the wiring of the battery pack has the connector polarity reversed from the LiPo.  If you plugged in a LiPo accidentally - the board wouldn't function but the diode in the battery path would prevent any damage.  So, I'm just going ahead and add the JST PH 2.0 connector.

 

MKR 1300 Battery Terminal Block

 

JST 2.0 Connector

JST PH 2.0 mating connector

Battery Connector Adapter

LiPo and Alkaline battery packs

 

Issue #2 LoRa Antenna cable is too long

I wasn't considering the close quarters when I bought the antenna cable and at 17cm length it doesn't fit well in the case.  I found one that's only 5cm long and I just received it.

Lora Antenna Cables

 

Issue #3 Connector locations required swapping GPS and Temp sensor board mounting

This was easy, I just moved the mounting screws.  Now the GPS is below the Temp sensor in the case.  Here is the printed insert in the case with all the mounting hardware for the PCBs and the mounted LoRa antenna.

LoRa Case with insert

 

Issue #4 GPS Antenna is poorly constructed

The antenna that I got with the GPS was not anywhere near "square", so it was difficult to mount cleanly although it works fine.  I decided to try getting another antenna and it is constructed much better.

Original GPS AntennaNew GPS Antenna

 

Issue #5 No space to use plug-in connectors to interface sensors to MKR 1300 board

I need to make a plug-on shield that will interface the sensor wiring to the MKR 1300 IO connector.  I always knew that I would have to replace the jumper connector wires that I used for prototyping with something more compact.  I just didn't allocate the time to build it.  This is what I am currently working on.  Once I finish this, the assembly will be complete.

 

Here's the proto PCB that I'm using.  Before I wire the header and interface connectors I need to cut the board shorter so it doesn't cover the antenna jack, battery connector and reset button.

MKR 1300 Proto Shield

 

Completed sensor assembly minus the proto shield and sensor wiring.  Antennas are connected.  PCBs mounted.

Assembly minus proto shield

Closed Assembly