I like these 128x64 1.8" SPI LCD displays:
I tested one with the U8g2 library with the full framebuffer graphics test example
(using the ST7565_64128N() constructor, not UCX1701X() which didn’t work).
IIRC I measured around 260 uA while active and 14 nA in powersave mode (not using the 16 mA backlight).
In powersave mode the display content is not visible.
Kind of…
The idea is to have a battery powered device to display some data.
MQTT wouldn’t work as it would be too power hungry.
I store all my TTN data in an InfluxDB database, and I expose a simple REST API to retrieve data.
So the ESP32 wakes up now and then (let’s say every hour), collect data, print them on ePaper and go back to sleep. If fresh data is needed, a button can trigger immediate collection.
ePaper is nice for this application as it doesn’t need power to maintain display
first parts for a 2019 project (a Pi-Rack server ) arrived 
Intesting to see. 3 Pi’s on 1HE or even more.
Keep on posting with this project.
I have print once this from
Also for a Pi Project in to a 19" Cabinet
very hard to find single alu Pi backplates, size = 50 x 100 mm (a bit to high for 1HE 
)
I imported them from a French audio company… very streamlined order process ‘tres bien 
’
I don’t know if I make the rack myself or use '10 inch rack materials
Grabbed a few of these on special last month for a remote control/automation on the warehouse/roller shutter in work to keep the warehouse manager happy. He’s always a couple of floors away from the door when the bell rings! Picked up some .mp3 players too for audio warnings. I plan to randomly “leak” qutoes from HAL9000 out of the speaker, just for a laugh!
#micorpython #mqtt #nolora
Interesting indeed.
A lot of stuff needs an ‘proper’ LCD for outdoor use, OLEDs and TFTs are almost unreadable.
The large 20x4 LCDs are great, but large.
Nokia 5110s OK, bit small, but not so reliable.
Those do look interesting.
For when you outgrow your current project, this solution can stash 70 RPi’s in a 3U unit, 980 total in a single 42U rack (V4 even 1350).
First “REAL” RPI rack V3:
you’re 3D printed gateway enclosure is famous now ! 
Wireless Charging Charger Transmitter + Receiver Power Supply Module 5V 1A Max
1A… really ? 
let’s test
* yep… they work as advertised.- so usefull
input 12v - 2A max - out no load 5.19 v
load 1A - 4.55 v
load 0,5A - 4.88 v
with 3mm polycarbonat between coils
Let’s make another one…
(ic880a + ch2i backplane version)
did you get an order from RAK
Funny you should ask that question…I did this morning!
Looks like my Black Friday buy from RAK has come in early - I ordered as standard Aliexpress del’y but looks like our friends have kindly shipped as 7-10day DHL 
3 x Rak Pilots + 2 x beefier external Ant’s
With 2 other self builds that should keep me busy through to and beyond Xmas 
With an ic880a? 
I still have a gateway on my workbench connected with Dupont wires waiting for an enclosure…
But this one is a #fail, I took the measure on the wrong place… 
oeps… 
waiting for my ordered dremel kit, the aluminium from this1590BB ‘stomp’ box is harder then I thought.
but it’ll make the cheapest ruggedised mobile enclosure
Has anyone experience with Nordic nRF52: nRF52832 / nRF52840 ?
The nRF52832 is a Bluetooth 5.0 SoC built around an ARM Cortex-M4F CPU with floating point unit, running at 64 MHz, has 512 kB flash and 64 kB RAM, I2C, I2S, SPI. The nRF52840 has 1 MB flash, 256 kB RAM (and supports multiple protocols, including Zigbee).
I was hoping nRF52832 may be used as general purpose MCU as alternative for ‘Arduino’ AVR or as a cheaper alternative for SAMD, possibly in combination with LoRa.
(There appears to be an Arduino Core for nRF52832 but I have not had a look at it.)
I bought two of these E73-2G4M04S1B modules (€2.69 each) here to give it a try.
Does anyone know a breakout board to make these breadboard friendly?
nRF52832. 832 and not 328
The SDK and the documentation from Nordic are very very good. The MCU is easy to put in sleep mode (just one line !) where it consumes ~1.2uA with RTC enabled. The 32 GPIO are configurable on any peripheral (I2C, SPI, UART…). That’s my favorite MCU.
For those who loves arduino, the drawback is the use of makefile and command line. But everything is provided with SDK. There is a nRF5 project for Arduino IDE: https://github.com/sandeepmistry/arduino-nRF5.
Typo’s corrected (ATmega328 was probably in my muscle memory). 
For nRF52840 dongle support I found: GitHub - Redferne/arduino-nRF5: Arduino Core for Nordic Semiconductor nRF5 based boards
