My super simple NRF51 touch buttons. I mostly use these to toggle overhead lights that I've converted to Tasmota.

@NeverDie I spent the last week really deep diving into NRF BLE & NRF networking capabilities.

Some things I learned:

• BLE is a great way for low power communication with a dedicated, physically close parent node
• BLE alone does not establish a network, just a link to a central/gateway node. Giving the limited range, that means having multiple gateways, and dedicated links (painful, inflexible)
• That led to the creation of BLE Mesh. I found this article from Integra Sources to be really helpful as they talk through the real world limitations they experienced trying to go to production with it. In summary, BLE Mesh is a "managed flood" which quickly leads to network storms if not optimized
• Then I found OpenThread
  
• After messing around for few days, I found this guide https://github.com/kyberpunk/openthread which really simplifies getting started. Two docker containers: OpenThread Border Router (sensor network gateway) and MQTT-SN (UDP6 MQTT bridge to MQTT Broker). I was able to setup a network with two NRF52840 dongles + NRF52840 DK, and post messages to my MQTT instance within a couple of hours.

OpenThread is supported on the the NRF52840, NRF52811, NRF52833, as well as 10-15 chips from other vendors.

I really like the ability to route via IP and the fact that all of the nodes communicate with common, well known protocols. I like the secure-by-default approach, and the built in tools for administering networks (commissioning new nodes).

I'm going to keep exploring this route, seems promising....

A bed occupancy sensor. 4 50kg load cells, an HX711, and a Wemos D1 to make a wifi scale that rests on a bed slat under the boxspring.

Given the placement and weight distribution it doesn't turn the bed into a huge bath scale, but definitely accurate enough to use the deltas to estimate if there is someone in the bed. I can also tell when our 12lb (5.5kg) dog is on the bed.

I have rules in openhab to turn the overhead fan on and off. Also disables some TTS notifications if somebody is in bed.

Just started testing my new NRF52805 breakout board. I added a new generic variant to sandeepmistry/arduino-nRF5, added a new board to mysensors nRF5, now I'm testing compatibility.

This new NRF52805 chip is interesting. Way stripped down compared to the rest of the NRF5 line. No PWM, no LPCOMP, only 10 GPIO (maybe 8 usable).

But, it's cheap, ~$2.50 for the EBYTE BT104-BT5005 module, compact, and appropriate for most low-power use cases.

Interestingly, the chip does not support the current MySensors default, but deprecated, data rate of 250Kbps. Today I also learned that modules can only communicate on the same data rate. So I created a ESP8266 + NRF24L01+ gateway at MY_RF24_DATARATE RF24_1MBPS, and it worked!

Still need to test a few things:

• I2C
• SPI
• Power consumption

If all goes well, I'll submit the merge requests and publish this board schematic on openhardware sometime in the next week.

nRF52805 BLE5.0 Wireless Bluetooth Module 2.4GHz Serial Port Receiver Transmitter CDSENET Smart Low-Power iBeacon Transmission

$2.32

Compact, simple NRF52 motion sensor
Ebyte E104-BT5032A NRF52832 module
MH-SR602 Motion Sensor
LiFePO4 AA Battery

@neverdie Yep, I had the same experience with this LTC3108 breakout.
https://www.aliexpress.com/item/LTC3108-1-Ultra-Low-Voltage-Boost-Converter-Power-Manager-Breakout-Development-Board-Module-Diy-Kit/32867270266.html

I also intended to try the following modules which have a ton of functionality baked in. Unfortunately, they multiply the cost of a basic node by 2-5x.

BQ25570
https://www.aliexpress.com/item/32903287631.html

BQ25504
https://www.aliexpress.com/item/32976994195.html

From an energy harvesting perspective, I think rechargeable watch battery + 0.2F super cap + 4 100uf is my favorite setup. Cheap, fault tolerant, very small profile if you use 1206 ceramic capacitors (not shown in this prototype). Based on this design: https://www.allaboutcircuits.com/technical-articles/overview-of-the-ble-solar-beacon-from-cypress-semiconductor/

0.2F 3.3v Capacitors
https://www.aliexpress.com/item/32577753501.html

3v Rechargeable Battery
https://www.aliexpress.com/item/32813917590.html

1206 100uf Capacitors
https://www.aliexpress.com/item/32376068793.html

Cheapest amorphous, indoor solar panels I have found: 2.7-3v
https://www.aliexpress.com/item/1854641441.html

Tiny S4 1N5817 Diodes
https://www.aliexpress.com/item/32813213875.html

LTC3108 -1 Ultra Low Voltage Boost Converter Power Manager Breakout Development Board Module Diy Kit

$6.43

HOT NEW battery MS412FE MS412FE-FL26E 3V Rechargeable Button battery charging with leg 20pcs/lot

$25.20

1206 SMD capacitor 100uf 16V 107Z 100pcs X7R

$4.05

Free Shipping! 10pcs TRONY low-light-type amorphous silicon solar panel photo module sensor

$5.60

New 1N5817 SOD-523 silk screen S4 Schottky diode 1A 20V 5817 SOD523

$1.00

USB + ESP8266 adapter for W2812B LED strip.

Well, this is actually a Tasmota + Openhab build, but could easily be MySensors.

Also worth noting, this 5m 150 led strip draws too much current to reliably use with a USB wall adapter.

@neverdie according to a few datasheets 2v at 200lux. The solar cells delivered were HENGYANG SC-3514.

http://www.vimun.cn/en/ProductInfo.asp?pid=18
http://www.solars-china.com/solars/indoor-solar-cells.pdf

On my windowsill, 2.5v typical in-direct sunlight, 2.7v is the highest I've recorded in direct sunlight.

So far, most of my Aliexpress buys have been fine for my needs. Haven't really gotten close to making a "production ready" module, so for prototyping it's been fine.

One exception: I thought I had a genius idea to repurpose these $1 solar powered keychain flashlights. They had an amorphous solar panel, rechargeable battery, button, leds and a housing...for $1. I bought 20 of them. First one I opened up, I realized it's a lie!

The solar panel is just glued to the circuit. The battery is just a normal non-rechargeable CR2016.

First attempt at a modular NRF52805 based board. The smaller board has a Si7021 temp + humidity sensor and a BH1750 light level sensor, both I2C. Ideally, I should be-able to make other sensor boards with the same footprint as long as the sensors are I2C.

Also included:

• CR2032 Battery (~1.5 years between battery changes)
• 10P 0.5 FPC connector for programming and serial debugging
• 2 LEDs with solderable jumpers
• On/Off switch (I find this really useful, especially when fighting with coin batteries)
• RST button
• Secondary button that I use to force immediate readings
• Footprint for centered button for alternative use as a remote button (my most common MySensors node)

I'll post pictures of the enclosure when it's ready.

I'm also waiting on delivery of a slightly larger version of this board that holds a 2477 battery and a SMD PIR motion sensor.

@waspie appreciate it, thank you

@berkseo Thank you!

First, I made the compatibility changes to SandeepMistry. This was surprisingly easy. The SDK in SandeepMistry/nRF5-arduino does most of the heavy lifting. I had to modify a few of the precompiler conditions to exclude PWM, change some serial definitions, and update to new handler naming conventions: https://github.com/sandeepmistry/arduino-nRF5/pull/442

Then, I defined a new Generic NRF52805 variant in mysensors/ArduinoHwNRF5 and handled one assumption of LPCOMP: https://github.com/mysensors/ArduinoHwNRF5/pull/12

Last, I had to handle a few small assumptions in the MySensors library: https://github.com/mysensors/MySensors/pull/1461

nikolac created this issue in sandeepmistry/arduino-nRF5

open Add support for Generic NRF52805 #442

nikolac created this issue in mysensors/ArduinoHwNRF5

open Add nrf52805 support #12

nikolac created this issue in mysensors/MySensors

closed Add nrf52805 support #1461

First attempt at a modular NRF52805 based board. The smaller board has a Si7021 temp + humidity sensor and a BH1750 light level sensor, both I2C. Ideally, I should be-able to make other sensor boards with the same footprint as long as the sensors are I2C.

Also included:

• CR2032 Battery (~1.5 years between battery changes)
• 10P 0.5 FPC connector for programming and serial debugging
• 2 LEDs with solderable jumpers
• On/Off switch (I find this really useful, especially when fighting with coin batteries)
• RST button
• Secondary button that I use to force immediate readings
• Footprint for centered button for alternative use as a remote button (my most common MySensors node)

I'll post pictures of the enclosure when it's ready.

I'm also waiting on delivery of a slightly larger version of this board that holds a 2477 battery and a SMD PIR motion sensor.

This is a great breakdown of the TP5000 charger.
https://lygte-info.dk/review/Review Charger TP5000 4.2-3.6V module UK.html

@willemx I believe below 3.3v it will basically pass through the input voltage with a minor drop, less than 0.2v. I also just tested this at 1.8v in the output is 1.787v (no load)...so not bad.

I use the XC6206 more often.

@willemx I have a MySensors weather station powered by a 5.5v solar panel, TP5000, and a AA LiFePO4 that has been running for 2 years.

I also have a couple of soil sensors with a similar set up. It's been very reliable.

If you take the battery out while the TP5000 + solar panel is still connected, I believe it will pulse 3.2 - 3.6v into your board. I would recommend using a HT7333 or XC6206 voltage regulator and a large capacitor, just in case.

You don't need to be super concerned with power efficiency. I find my small solar panel tops off the battery within the first hour of indirect sunlight.

@Didou Which NRF5 module are you using exactly?

I also believe this code from your sketch is unnecessary, given MySensors handles most of it:

void nRF_Init() {
  NRF_POWER->DCDCEN = 0; // Not reducing the radio current   
  NRF_PWM0  ->ENABLE = 0;
  NRF_PWM1  ->ENABLE = 0;
  NRF_PWM2  ->ENABLE = 0;
  NRF_TWIM1 ->ENABLE = 0;
  NRF_TWIS1 ->ENABLE = 0;
  //NRF_RADIO->TXPOWER = 8;
}

void disableNfc() {
  NRF_NFCT->TASKS_DISABLE = 1;
  NRF_NVMC->CONFIG = 1;
  NRF_UICR->NFCPINS = 0;
  NRF_NVMC->CONFIG = 0;
}

void turnOffAdc() {
  if (NRF_SAADC->ENABLE) {
    NRF_SAADC->TASKS_STOP = 1;
    while (NRF_SAADC->EVENTS_STOPPED) {}
    NRF_SAADC->ENABLE = 0;
    while (NRF_SAADC->ENABLE) {}
  }
}

@Didou for my testing, I pulled the entire branch referenced in the merge request. I believe that is MySensors-development + nrf_esb_redesign changes. But you're probably safe to just replace the two files touched in the commits.

@Didou There is currently a bug in the NRF5 transport layer that causes them to lock up. It seems more likely to happen when the connection between the gateway/repeater is weak or too far.

You can read more about it here: https://forum.mysensors.org/post/108301.

My understanding there is a fix pending review and @waspie has been testing it with some NRF51822 modules.

@Avamander That would make a great gateway. I believe I read a getting started guide by the creator of that Pi Hat, Playing with Thread and MQTT-SN on Nordic nRF52840. The tutorial is a little outdated now, but it's a good overview of the process of setting up a Thread network. There is a lot of good content on that blog.

I agree, but it is still not clear to me what the appropriate relationship between MySensors and OT / BLE Mesh is. It seems there is a lot of overlap in functionality. While I prefer to focus on the NRF5 series, a majority of the community is using ATMEGA328 and NRF24, or LoRa modules, which wouldn't support OT / BLE.

At the very least, I'd like to see MySensors tap into some more of the advanced NRF5 capabilities: OTA, NFC.

There are also a few examples of NRF5 modules running in dual mode: BLE + OT. If it's possible to run 2.4GHz + BLE in parallel, then there is potential to create a MySensors bridge device.

Or maybe leveraging BLE to configure MySensor nodes at runtime: modifying sleep duration, send frequency.

Given the abundance of storage and memory on the NRF5 devices, it is also feasible to create something like Tasmota / ESPeasy for MySensors. Use the same firmware on every node, have the MySensors gateway/controller manage and push configuration templates. Given the great work on MySensors NodeManager and the SmartSleep functionality, it seems like the foundation is already in place.

@NeverDie Thanks, and good call on the Ebyte NRF24 with LNA. I have a few laying around that I've been meaning to incorporate into a generic multi-sensor gateway/repeater node. If they're always connected, might as well collect environment data and maybe motion too.