jaredwolff Yes, adding a SWD connection to the nRF9161 sounds good.
I know it’ll increase the cost but how about adding a BME680? It opens the door to a quite a few other use cases for customers, including embedded machine learning.
I guess, one of the reason for the RP2040 selection was the availability of an open-source DebugProbe firmware vs. licensing Segger J-Link OB firmware running on nRF52840 or nRF5340. Plus the open-source option allows future enhancements.
zpm1066 I know it’ll increase the cost but how about adding a BME680? It opens the door to a quite a few other use cases for customers, including embedded machine learning.
This has something other customers have asked for in the past. I’d consider it but it may push the cost way to far to make the project sustainable.
jaredwolff Thanks. A BME280 at half the cost of a BME680 may be worth a consideration.
I use the BME688 in Thingy:53 and Adafruit BME688 breakout for prototyping; and BME688/nRF52840Dongles in a Thread network. In addition to BME680 features, the BME688 has a gas scanner function for ML. BME688 costs ~$7 per 100, about the same price as a BME680; and BME280 is ~$4 per 100. Personally, I’d pay the extra and go for the BME688.
AchimKraus I guess the question is more, will the new feather be a “complete DK with debugger”. I’m not sure, if that will be the right way. The new nRF9161-DK comes at an even lower price than the nRF9160-DK. Both comes with a well working software stack.
I didn’t realize that nRF9161-DK is considerably lower in price than a nRF9160-DK. A quick check on mouser.com shows nRF9161-DK ~$99 vs. nRF9160-DK $155.
It’ll be interesting how Nordic will price the upcoming Thingy 91:X (nRF9151, nPM1300, nRF5340, nRF7002, nPM6001, and same sensors as Thingy:53) and nRF9131-EK (nRF9131, nPM1300, Segger J-Link OB Programmer/debugger). Both of these offerings will be excellent for prototyping.
I would use the nRF9161 Feather boards as deployment devices with easier development accessibility, either a Mini SWD 10-pin connector or the proposed design.
In my experience of the past years:
All that, and the new price of the nRF9161-DK, ends up in my conclusion, that a developer will have such a nRF9161-DK. Those who only use demos and slightly modify them will be happy with the USB bootloader.
The Thingy is nice, I also use a couple of them. But once you need your own sensor, or other batteries or antenna, then the nRF9160 feather is still the best in class.
zpm1066 I would use the nRF9161 Feather boards as deployment devices with easier development accessibility, either a Mini SWD 10-pin connector or the proposed design.
That is exactly also my usage. For example the Mobile BeeHive Scale is built with an nRF9160 feather, a Thingy:91 is missing expandability and a DK is just to large in size.
jaredwolff
Is there any reason why you wouldn’t want to use the nRF9151 over nRF9161 other than perhaps pin compatibility with nRF9160?
From the specs, nRF9151 looks to be identical to a nRF9161 with the addition Power Class 5 20dBm and , of course, a smaller packaging. What advantages does nRF9161 provide over nRF9151?
AchimKraus The Thingy is nice, I also use a couple of them. But once you need your own sensor, or other batteries or antenna, then the nRF9160 feather is still the best in class.
In the few Thingy:91X perspective photos shared from MWC Barcelona 2024 and the recent Embedded World exhibitions, it looks like Thingy:91X may be supporting an EB (Expansion Board) like Thingy:53. If so, then we may get I2C, SPI and several GPIOS for sensors and peripherals. It definitely has an I2C STEMMA connector, plus holes for ‘charge led’ & ‘led2’ above the USB-C and STEMMA connectors. As yet, I don’t see an “edge_connector” defined in the thingy91x devicetree in NCS v2.6.0/nrf/boards/arm. Thingy:91X release was suppose to be in Q1 but looks like it’ll be in Q2, so perhaps work in progress.
Thingy:91X
If it gets extendable, that will be nice. Exchanging the battery and antenna has also some benefit, so at least I will continue to use feathers for prototypes and the thingy:91 mainly as “network discover and tester”.
AchimKraus That is exactly also my usage. For example the Mobile BeeHive Scale is built with an nRF9160 feather, a Thingy:91 is missing expandability and a DK is just to large in size.
For LTE, I’ve been using Particle Boron Feather boards with nRF52840 / UBlox SARA modem, though these are not low power like the nRF91xx. I’ve been pretty satisfied with their Borons. BTW - Their EOL Xenons (nRF52840) make excellent Zephyr dev boards. A few online places still have old stock.
I haven’t come across any nRF9160 boards in a Feather format that satisfy my requirements in terms of a SWD 10-pin J-Link connector for ease programming/debugging. I was planning on designing my own nRF91xx Feather but thought I’ll check what Jared’s plans are going forward for the next iteration of his board. Why re-invent! Hence, the reason for starting off this topic last year.
However, Jared’s proposed design for a nRF91xx Feather checks off several asks - nPM1300, SWD Programmer/Debugger, and eSim. So, I definitely hope to use these nRF91xx Feathers for future deployments and development.
I’m only interested in real low power devices. Leave the other stuff for the MQTT folks ;-)
I guess Jared remembers, that before I ordered the first feathers I asked him in a private e-mail, if the feather really goes down to 10µA (because the Thingy:91 before v1.6 was more about 35-40µA and only, if you disable the 3V in deep sleep).
A “low power device” (beside of a lot of marketing plurr, the nRF9160 is the only kid) accompanied by a “low power protocol” (CoAP/DTLS 1.2 CID) enables to build battery solutions and makes such devices much more independent.
E.g. the Mobile BeeHive Scale runs from 3xAA 2000mAh (LSD) more than a year in the “wild” (in theory even 2 years ;-) ).
zpm1066 Is there any reason why you wouldn’t want to use the nRF9151 over nRF9161 other than perhaps pin compatibility with nRF9160?
They are actually not exactly pin compatible and does require a footprint change.
From the specs, nRF9151 looks to be identical to a nRF9161 with the addition Power Class 5 20dBm and , of course, a smaller packaging. What advantages does nRF9161 provide over nRF9151?
It’s available now vs waiting a while for the nRF9151. I do have an idea for the nRF9151 since it allows for more room. There’s still time to switch but I’m limited by when Nordic can deliver.
jaredwolff It’s available now vs waiting a while for the nRF9151. I do have an idea for the nRF9151 since it allows for more room. There’s still time to switch but I’m limited by when Nordic can deliver.
I suspect nRF9151 availability may be closer to Q3. Probably similar for the nRF54xx as well.
Btw - Have you considered doing a Feather board with nRF7002 with either nRF54L15 or nRF54H20?
In the meantime I got it, that the RP2040 will be used as USB bridge, and though on the board, maybe for swd. For the USB bridge it would be great to have two channels, that makes getting trace easier. I guess, there are then drivers for such an USB bridge, for Ubuntu and Windows? Mac?
About the swd: The thingy:91 has a switch to select the target. Maybe that’s also an idea.
I need your input!
Your thoughts on preferred VDDIO? The options are 3.3V or 1.8V. I could go either way right now. There would be longer term savings if 1.8V is used. Depends on the application though.
And a little preview. 
Hi Jared,
as for now, in my opinion, 3.3V helps the “makers”. Quite a lot of sensor boards are for 3.3V (or 5v). To craft the first 100 devices will benefit from 3.3V in my opinion. I consider, that in the most cases, it’s decided with that 100 to either build a product or not. So for me, 3.3V is preferred.
The other idea would be to connect the “battery” direct to the modem and make VDDIO “configurable”. That depends on the other ICs on the board, if that works. And for me, it’s not that important.
Just for those, who are interested; that’s a nRF9160 feather v5, running from a 2000mAh LiPo for about a year. Exchanging a message with encryption over CoAP/DTLS 1-2 CID.
@AchimKraus thank you for sharing!! The chart is also fantastic.
I’m still a bit of a noob compared to Achim and zpm, but my view is that you should keep it to 3.3v - Even if there would be powersavings by going to 1.8v, it it already so low that pushing it even more wont really matter, but as you also state, the hurdles to newcomers might be significant since a lot of other stuff out there needs 3.3v.
We use GPS on some of our things, but I did find it a bit odd that it was included by default rather than being an “addon” initially.
RGB LED is no doubt a great addition, and i’m looking forward to eSim!
Thank you @JeppeMariagerLam for your feedback 
JeppeMariagerLam We use GPS on some of our things, but I did find it a bit odd that it was included by default rather than being an “addon” initially.
Can you elaborate more here? I’m not sure what you mean. The fact that you needed a separate antenna?
jaredwolff yes, we have an external antenna, for example mounted on the top of a car rather than inside the steel box where the unit is connected to power.
