Receiver via USB vor you could attach a "wixel" (see xBridge) via usb-serial and get the values with that
G5 - don't know of the rpi could emulate beeing a phone and connect to a g5 transmitter like a phone with XDrip
Also.. When using g5 I'd still suggest a cheap g5 compatible smartphone with xDrip+ ... then you have many possibilities for sending it somewhere else ;)
@realjoshfreeman you might be able to get g5 data directly to your rpi3 have a look at xdrip-js
For G4 use the Wixel to USB
For G5, it is bluetooth. I'm not sure if the raspberry can interface with it.
Thanks, those are some good jumping-off points.
Looks like for the G4 it's a wired connection to the receiver only. Can you do the same thing with the G5, if you're using the receiver rather than a smartphone?
Also, I'm hearing conflicting reports on whether it's possible to use both a smartphone and the receiver simultaneously with the G5. I was thinking the Dex docs said no, but then I saw somewhere else that you can always use the receiver whether there's a smartphone connected or not. Can anyone clear that up?
The RPi3B has both Bluetooth and WiFi onboard. I'm imagining a system that could gather readings and send to the cloud via WiFi or USB LTE modem (cheaper service than a full phone), or directly to me via private packet radio if Internet were unavailable or unreliable.
@realjoshfreeman the G5 can have a stock receiver, and another device paired to it
@realjoshfreeman@ClearSimpleAndPlain xdrip-js works to get data from g5 transmitter via Bluetooth on the pi zero w, so I'm sure it would also work on rpi3
@realjoshfreeman : from personal experience: the G5 does communicate with one medical device AND at least one non-medical bluetooth device "simultaneously". The medical device can be a Dexcom G5 receiver OR a Tandem X2 Insulin pump OR another compatible medical device. The phone however will be a hit or miss. Currently I use a dedicated $0 samsung amp 2, it is connecting to the G5 right away and the capture rate is a consistent ~95%. I tried several other cheap phones (ZTE Blade, LG Stylo, with varying success). If interested in the smallest system with lora, oled, BLE, Wifi, Simplicity integration at sub $50 parts cost,you may want to look at the https://hackaday.io/project/27791-esp32-lora-oled-module and the https://github.com/Gorgy70/xDrip-ESP32 project (google translate will help).
any word on whether G6 will use the same BLE protocol as G5?
No clue, likely there may be minor changes with raw values and calibrations but those are mere speculation at this point it was only approved yesterday Dexcom isn't even shipping them yet from what i heard
Hi, @gszakacs and @ecc1. I'm quite new to this channel, but I noticed from your previous posts
That we share the same interest in both sniffing the Dexcom G4 2.4 band and transmitting to sub 1ghz band. Have you tested the ESP32 AND cc1350?
@Technixx I haven't. I don't want another device that needs firmware, so I prefer SPI-only radios controlled by a Linux host. CC2500 works well for that.
@ecc1 Ok, I guess that requires some soldering? What unit are you using to compute? Size does matter for me because the loop system is for a 3year old. Is the CC2500 (can check it up also) just sniffing without any transformation from the G4? And what do you use to transmit back to the pump on the sub 1ghz?
@ecc1 BTW do you need to implement the APIs yourself or are they readily from TI?
my transmitter isn’t out of warranty until July :(
nope, and same here
Hi all, does anybody have the formula to calculate BG from the raw number that the G4 transmits? I am trying to build a sensor simulator to test transmitters
@LilDucky - only seen the g5 raw data, but assume it is similar. For testing purposes, you should just be able to simply divide the filtered/unfiltered value by 1,000. I have a shell script that will do linear squares regression given calibration data, but I would assume that would be overkill in this case.
You still have to apply the slope and offset calculation after you divide by 1000
If the calibration is valid
@efidoman@TecMunky thanks. I have built a really rough sim with a 10 turn pot for the value but now need to translate this into an arduino based tool that can set a known value or give a sinusoidal waveform
and assume that these values are in mg/dL
my testing so far gave me this
will share the design once the bugs are worked out
@LilDucky are you connecting to the two pads on the bottom of the transmitter?
If so. What kind or signal are you feeding it?
@ClearSimpleAndPlain yes I am with a modified version of the base of an old sensor. It is a DC current of between 100nA and 1000nA at this stage
What voltage do you use?
it is a current source sensor and between 100nA and 2uA from what I can tell
Ok, but what voltage do you use to create that current?
I am using an arduino PWM pin driving a filter
I just received a shiny new G6 yesterday evening and have it working with xdrip, nightscout, & my openaps rig (online only). Would like to get back to looping offline asap so I'm motivated to help out however I can.
@Jonathan-Cole you can have a look at the xdrip-js channel, where it sounds like @efidoman just has an alpha version of the code ready for the g6