Range tests of Medtronic CareLink USB Stick

(A) CareLink-Range-2.md

CareLink USB Range Testing: Test #2

Setup and Notes

• Date: 2015-09-09
• Pump: Medtronic Minimed 723 v2.4A pump
• Pump Battery: Full
• Pump suspended
• CareLink USB stick plugged directly into RPi2 USB using 6" extension
• Pump and CL stick placed on hardwood floor
• Did not attempt reorientation of pump during test
• openaps use pump read_clock used to test communication; openaps use pump status and openaps use pump settings found to show same range
• Successes and failures repeated when pass/fail threshold determined to check for consistency
• Antenna on the CareLink USB stick is on the side of the PCB close to the large "CareLink" text (the "top" side), furthest from the male USB adapter

Results

ID	Stick	Orientation	Pass Distance [ft]	Fail Distance [ft]
01	Encased	Flat, CL Text Up, Tip Towards Pump	5.5	6.0
02	Encased	Flat, CL Text Down, Tip Towards Pump	8.0	8.5
03	Encased	Flat, CL Text Up, Lower Edge Towards Pump	9.0	9.5
04	Encased	Flat, CL Text Up, Upper Edge Towards Pump	7.5	8.0
05	Encased	Flat, CL Text Down, Upper Edge Towards Pump	9.0	9.5
06	Encased	Flat, CL Text Down, Lower Edge Towards Pump	9.0	9.5
07	Encased	On-Edge, Bottom Towards Pump, CL Text Upside Down	12.5	13.0
08	Encased	On-Edge, Top Towards Pump, CL Text Upside Down	10.5	10.0
09	Encased	On-Edge, Bottom Towards Pump, CL Text Right-Side Up	11.0	11.5
10	Encased	On-Edge, Top Towards Pump, CL Text Right-Side Up	9.0	9.5
11	Naked	Flat, CL Text Up, Tip Towards Pump (see ID 01)	6.5	7.0
12	Naked	Flat, CL Text Down, Upper Edge Towards Pump (see ID 05)	10.0	10.5
13	Naked	On-Edge, Bottom Towards Pump, CL Text Upside Down (see ID 07)	12.5	13.0

Analysis

• There is nontrivial directionality when it comes to the CareLink USB stick orientation
• Directional affinity shown here may be related to pump orientation and/or proximity to the hardwood floor, not simply which face is "pointing" towards the pump; this was not explored in these tests
• Removing the plastic case appears to add a marginal amount to the range (0 - 1 ft)

Photos

Setup:

CareLink Case Removed:

01:

02:

03:

04:

05:

06:

07:

08:

09:

10:

11:

12:

13:

(B) CareLink-Range-1.md

CareLink USB Range Testing: Test #1

• Date: 2015-09-01
• Pump: Medtronic Minimed 723 v2.4A pump
• Pump Battery: Full (installed previous day)
• CareLink USB stick plugged directly into RPi2 USB port
• Both placed on table, stick "pointing towards" pump

With space between and around pump and stick clear:

$ openaps use pump read_clock: successful at 66" (ran out of space)

$ openaps use pump status: successful at 66" (ran out of space)

$ openaps use pump settings: successful at 66" (ran out of space)

With RPi2, CareLink USB stick, and battery in a , zipper closed:

$ openaps use pump read_clock: successful at 60" (failed at 66")

$ openaps use pump settings: successful at 60" (failed at 66")

Setup in case, on belt at left hip; pump on belt at right hip; approximate distance = 17" (through body)

$ openaps use pump read_clock: failed