If you don’t know what a xDrip device is take a look at this page.
I was tickled by someone on Reddit who linked to yesterday’s blog about the components required for a xDrip which was entitled “An “Amateur” builds a module for DexDrip”. So here it is, this amateur’s guide to building an xDrip/DexDrip. (The article actually referred to DexDrip as that what xDrip was called at the time.)
A baptism of
Although I received lots of offers of help to solder the components together the guys at work told me I’d have no trouble doing it myself, so I decided to try.
First I ordered the soldering kit (iron, solder, stand, helping hands, solder sucker) from eBay and a practice board to train myself with. The ‘helping hands‘ turned out to be worth their weight in gold.
I soldered my first pin, inspected it and then soldered three more, choosing to solder them right next to each other as it seems that a common problem for amateurs is putting too much solder on. With four pins soldered I tested everything for continuity issues, to make sure no excess solder had spilled on to the adjacent contacts and shorted anything out.
My AdaFruit LiPo-charger came with a connector, my battery came with a connector; they weren’t the same.
First job then was to cut the wires from each and solder the battery wires to the LiPo-charger connector.
NOTE: some people remove the connector terminal on the LiPo-charger and solder directly onto the charger board, I didn’t fancy this as I like to be able to disconnect batteries and swap them easily.
DO NOT connect battery to LiPo-charger.
The AdaFruit Li-Po battery charger then needed a power (red) and ground (black) wiring up.
For my first try I soldered a four-piece-header-pin to the board and used jumper wires to connect to it, but within a week I removed the header pins & soldered the wires directly onto the PCB.
1. Red wire, solder on to 3.3v (marked as BAT on mine), first on the left as we look at that board. Make sure you don’t solder on to the 5v connector.
2. Black wire, solder on to one of the GND connectors, for ease I chose the 3rd from the left.
Prepare four wires (red, black, green, blue) with one female header pin at one end and bare wire for soldering at the other.
1. Black, solder to GND
2. Red, solder to 3V3
3. Blue, solder to P1_6
4. Green, solder to P1_7
Other possible options: The header pin option is the simplest way to connect from WIXEL to HM-10.
The hardest (but not too bad) option is to desolder the HM-10’s header pins, then solder wires with two bare ends onto the WIXEL and to the HM-10.
The middle option is to solder wires with two bare ends, one end onto the WIXEL and one bare end onto the relevant header pin on the HM-10. Whilst this might seem easy I think it’s simpler to desolder the HM-10s header pins as above.
What you do next depends on what you chose to do on the ‘Connect wires for bluetooth module to WIXEL’ step:
If you soldered wires with female header connector at one end when you did the step above then all you need to do next is to slide the correct colour wire’s connector onto the correct HM-10 pin as per the diagram here.
If you soldered wires with two bare ends and left the header pins on the HM-10 then you need to solder the bare wire ends to the correct HM-10 header pin as per the diagram here. This is tricky to do (for me) but not impossible as I found when I made a second xDrip. I choose to wrap electrical tape around each soldered pin/wire afterwards.
If you soldered wires with two bare ends and removed the HM-10 header pins then just solder the bare ends onto the HM-10 as per the diagram here.
With the LiPo-charger disconnected from the battery (and micro-USB power) you now need to solder its wires to the WIXEL.
Red, solder to VIN
Black, solder to GND
Hopefully by the end of it you’ll have something that looks like this:
Note: the picture shows header pin connections for the AdaFruit Li-Po charger but I’ve now soldered the wires directly to the board, it now has a much smaller footprint.