PPK2 with feather

Nwre

Hi! I want to use the PPK2 to measure the power consumption of my feather. Some problems though: My feather is soldered to a shield custom made for prototyping. The connectors are exposed though so I can maybe wrap a jumper cable around a connector, which I tried. I did this and connected the BAT and GND of the feather to the VIN and GND of the PKK2 but the output I see is so small it cant be correct. Also I see no difference if the LTE is sending or not. I am using a battery to power it, however, to get it started I first connect a usb (when battery is plugged in to feather), reset the device and remove the usb connection.

How many things am I doing wrong and can it be done right?

Regards

AchimKraus

connected the BAT and GND of the feather to the VIN and GND of the PKK2

Check PPK II - Quick Start

| battery / power supply | PPK II | feather |
| -------------------- | ------ | -------|         
| +                                           | Vin       |                 |
|                                              | Vout     |  BAT        |
| -                                           | GND       | GND         |

(I will add the feather to Zephyr coaps client / measurements ).

jaredwolff

@Nwre it doesn’t quite work that way.

Connect one of the ground wires to GND on the nRF9160 Feather.
Then you’ll need to connect the + from the battery itself to the VIN port on the PPK2
Then you connect the out to the VBAT pin on the board.

You may need to create an inline JST connector to easily measure the battery current.

Alternatively, I’d recommend you simply provide power from the PPK2 and not use a battery. The PPK2 is adjustable and has the ability to provide enough current to the nRF9160 Feather to do any current measurements as necessary. (In this case you will need the VOUT and GND pins connected to the VBAT and GND respectively)

Nwre

jaredwolff much thanks to the both of you. That sounds reasonable, never before has an area of interest made me feel so simple but I’m learning a lot and I thank you. I’m going to spend my weekend experimenting and will update with results (the wife shares about 1/1000th of my excitment)

Nwre

jaredwolff I got it working with a blinky example. I did not use a battery but went straight for the ppk2 to power the feather. I am a bit confused as to what supply voltage I should use. When I run it on battery only it, according to the battery sample, starts out at around 4,2 mV and then drops down to around 3,3mV as the battery depletes.

Nwre

Alright, I am very happy with the instructions, the results and everything. Thanks guys, it works wonders. I’ll get back to my FOTA thread soon 🙂

AchimKraus

You may need to create an inline JST connector to easily measure the battery current.

One point I really enjoy at the feather is the BAT pin 1 on J2. On a breadboard you just stick it, you don’t need any (inline) JST connector. That pin does a great job on both in both modes “source meter” and “amper meter”.