The WORKBENCH part 2



don’t turn it on, take it apart! ’ © Dave :wink:


google assistant fun :rofl:




it’s my TTN Anniversary today … time flies when your having fun :wink:

(Jeff Uk) #257

Yippee! New toys arrived yesterday! :slight_smile:
2 x RAK Pilot Gateways:-

…complete with a couple of bags of sweets…:slight_smile:

I teamed up with another delegate to the recent TTN-UK Conf in Norwich, where Pi-Supply were participating/exhibiting, to do a joint buy of a few of these and secured a small but useful discount from John and the @PiSupply team (Hi Guys!).

One will be used ‘as is’ for more regional test/pop-up deployments around the UK, the other likely re-housed for external use at a candidate site with a supporting PoE feed…

Good timing as had just finished commissioning/testing a couple of new self builds based on RAK831/RPi2 using RAK interface board and RAK831 + RPi0W using @Charles (Old Rev 1.3b) i/f boards so now I wont be idle this weekend! :slight_smile:

Package content:

RAK Pilot GW …Check
868Mhz Ant…Check
5V/2A PSU…Check
Compliance doc sheet…Check
GPS Ant…Check
3m sticky pad for poss GPS mount…Check
uSD Card for S/W…AAhhh! :-:cry: Maybe not! :frowning:

So no quite a full ‘self contained’ system…shipping with a suitable 16Gb card with say TTN EU image (its 868Mhz build after all) would have been nice and not too expensive (Only just over £3 per as ‘add on item’ from Amazon at the moment)

Ah well easily solved with a raid on the spares draw…

:scream: Oh No out of stock! - used last 2 on the above builds :frowning:

5 mins later and 2 x £3+ lighter courtesy of Amazon new cards en route and due here for Sunday. :slight_smile:

…guess I will need to hide the Haribo’s from the kids and and keep myself busy munching them until the uSD cards arrive…:-:grin:

These two new GW’s plus another couple of builds planned for next 2-3 weeks mean I’m on track to hit 20+ GW’s registered on TTN in UK by Xmas :thinking::sunglasses:

(Jeff Uk) #258

Anniversary…congrats! :slight_smile: Think my 1st is next month…like you say Tempus Fugit when having fun!.. :slight_smile:

(Shawaj) #259

Glad we could help you out! Enjoy @Jeff-UK


looking for flux in China… and I bought these :rofl:


then you suddenly realize why there are So many empty stores in city centers :hushed: I’m part of the 'problem

(Jeff Uk) #261

uSD Cards just arrived 24hrs early so guess my time this afternoon is now destined for a black hole…lost forever! :slight_smile:


A possible idea:
I have seen someone using it to display icons to geeky spice-up his Bluetooth presentation. The icons were automatically sent from within the presentation via Bluetooth.

(Remko) #263

What do you do when you have an old housing, some nice buttons from an gamble machine, spare time and inspiration? You build a LoRaWAN TTN-survey station! :slight_smile: :slight_smile: :slight_smile:



and the software, you use different ports or the same port and change the value ?

seems to be a hot use case in hotels/bars/restaurants ect … with a small investment (no wiring ect) the manager can see on his phone how angry or satisfied the clients are :scream:

(Remko) #265

I have not decided yet. I do consider collection of data by the device over time both agregated and over periods. I could use ports to discriminate between information type.
So the question is: how much intelligenct with respect to teh application shall be inside the node?


I guess some ‘protection’ against idiots pushing 20 times all buttons within 10 seconds.
after all… they are arcade buttons… :wink:

(Remko) #268


I am thinking of:

  • XOR funtion to prevent pressing multiple buttons at the same time:
  • Debouncing on steriods to prevent excessive pressing of a button.
  • Some strategy to prevent abuse of the device. No clue how yet.





new 2 x 5 W little speakers arrived - hoping to improve RPI assistant sound compared to the 2 x 3 W I use now.
I’m experimenting also with these little cheap Chinese amplifiers:

amp 2x3 W -
amp 2x5 W -

I’ve planned to build the Google Senior assistant system in 2 big, but low enclosures, one housing the RPI 3A / amplifier/ battery /wireless charger receiver / speakers and in the other one (the craddle) the wireless charger transmitter.

Its an Christmas present I’m working on for my old mother, she can’t use a keyboard/computer because she has shaky hands.
That’s why I set it up so that she don’t have to connect the assistant to charge but just put it on the wireless charger, it clicks in the right position because of a magnet.
There is a led indicator when fully charged.
Also its a mobile device , she can take it to another room / bed and in the future she can control things with voice commands. (recognizing the word ‘help’ and then calling someone when she falls for example)

Only problem sofar… still no Dutch language available


How to drastically improve battery life of an EEVBlog uCurrent Gold

Most of the uCurrent’s battery power is consumed by its LED (‘BATT OK’). So battery life is mainly determined by the LED’s current (not well-designed for a device focused on low-current and itself powered by a tiny battery).
The LED is on when the device is powered on and battery voltage is 2.65V or higher. The warm-yellow LED has a 270 Ohm series resistor and draws around 3 mA current.

Replacing the LED with a bright version and a much higher valued series resistor will drastically decrease current consumption and therefore improve the battery life.
After replacing the LED on my uCurrent Gold (rev5) with a bright green one and replacing the 270 Ohm series resistor with 20k Ohm, the LED draws only 42 uA current (@3.0V) which is only 1.4% of (71 times smaller than) the original 3 mA!

According to the uCurrent Gold’s specifications battery life should be at least 50 hours when using a standard CR2032 cell (220 mAh) with 2.65V cutoff voltage.

Below discharge curve shows that the maximum capacity that can be consumed with 3 mA discharge current and 2.65V cutoff voltage is around 80 mAh.

Image source:

To light the LED with 3 mA for 50 hours requires 150 mAh capacity which is much more than the 80 mAh that the curve shows. Even if the values in the curve are taken with a grain of salt, the specified 50 hours battery life is probably still too optimistic. And that is only based on the LED current, not taking into account the current consumption of the uCurrent itself, which - based on the uCurrent Gold’s specifications - will probably be very small when compared to the current consumed by the LED.

Therefore minimizing the LED’s current will have a major positive effect on the battery live time.

Notes: It is difficult to find CR2032 discharge curves for currents in the mA range, many available CR2032 discharge curves only cover discharge currents of 100 nA and lower.
Many manufacturers base their specified CR2032 capacity on a 2V cutoff voltage, so with the uCurrent’s 2.65V cutoff voltage an important part of the specified capacity will not be used. Also the constant discharge (LED) current is relatively high for a CR2032 battery which further reduces the battery’s usable capacity.

uCurrent%20Gold%20rev5%20-%20Original%20-%20315x326 . . uCurrent%20Gold%20rev5%20-%20Led%20modification%20-%20315x326

On the left: original yellow LED with 270 Ohm resistor and on the right: LED replaced with bright green LED with 20k Ohm resistor (smaller LED because I had no larger).



With only 42 uA the LED is still clearly visible




VNC viewer works nice with RPI model A






The other day I was taking apart an old laptop but didn’t have the right tools… very frustating :face_with_raised_eyebrow:
Happy that my Metal-Socket-Driver-Wrench-Screwdriver-Hex-Nut-Key-Nutdriver-Hand-Tools arrived :stuck_out_tongue_winking_eye:



very quit … everything ok there in your workshop ? :wink: