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Howto: Node Red Subflow for Hue Bulbs

When writing some flows for Node-RED controlling my Philips Hue bulbs; I wanted to read from a bulb do some work then write that same colour back to the bulb. When you perform a GET on a bulb, you get all of the information, whilst good this means it is a bit more inconvenient to PUT that back into a bulb as that API has a slightly different resource shape where the colour mode is determined by which values are submitted.

After using a group of nodes in one flow which did exactly this, I needed the same block in another flow. So I created a sub flow by selected those nodes, clicking the hamburger menu in the top right and choosing 'Subflows > Selection to Subflow'. This replaces the selected nodes with a single node which you can edit in a 'subflows' menu group in the left pane.

Download this selection and make your own subflow:


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Howto: Ubuntu 8.10, Dell 5530, 3G/WWan and GPS

There is an updated howto on the Dell 5530 using my own python based monitoring tool at


Here is a Howto document for getting the Dell 5530 wwan card working along with the onboard GPS under Ubuntu 8.10. This card does not work conveniently with the bundled Network Manager software, but replacing NetworkManager with other utilities will give the ability to get online using a pretty GUI and not have to resort to using wvdial and the command line...

It should also work with the Ericsson f3507g as I believe the Dell 5530 is a rebadged version of this module.

Check Hardware

First you need to check the modem is detected correctly. On my computer, the modem is detected out of the box by the cdc_acm module and exposes three serial ports (/dev/ttyACM[0,1,2]) for communication. Check by running:

dmesg | grep ACM

Mine shows the following:

[ 34.385302] cdc_acm 1-6:1.1: ttyACM0: USB ACM device
[ 34.390039] cdc_a…

Dell 5530/Ericsson f3507g on Linux

A few months back I posted a howto guide on getting this mobile broadband card working with Linux, what I failed to mention was I continued to work on these scripts. I feel it is appropriate to post a status update on what I use now especially given there appears to be no further updates on the NetworkManager front.

I no longer use UMTSMon as I found it relied on AT+CSQ for the signal quality and during UMTS and HSPA connections, the f3507g/dell 5530 returns either the previous GPRS value or 99,99 which UMTSMon considers as no connection available.

I've used a simplified wvdial.conf scripts and now do the rest of the radio work using python.


# Author: Barry John Williams
# Creative Commons Attribute-Share Alike 2.5 UK:Scotland Licence

[Dialer defaults]
New PPPD = yes
Stupid Mode = 1
Modem Type = ACM Modem
Modem = /dev/ttyACM1
Init1 = AT
Init2 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
Init3 = AT+CGDCONT=1,"ip","internet"
Baud = 460800
ISDN = 0
Phone = *99***1#

BBC Micro:bit Toothbrush Timer

A few months back I bought a BBC Micro:bit at the Science Centre in Glasgow and it's been fun building apps with the single board device. I thought I'd write a blog entry about the latest project which will be a more permanent installation in our bathroom.

A toothbrush timer!

Kitronik sell an add on board which provides power from a coin cell battery and a piezo buzzer called a Mi:power, they also sell a Mi:power case which is designed to fit around a Micro:bit fitted with the Mi:power. This assembly combined with some code offers a neat toothbrushing timer. By using the display on the front we provide a short countdown - with a little tune through the buzzer. The program show 6 areas of the mouth to brush each for 20 seconds before showing a toothy grin and a finishing tune. Each time the area of the mouth changes it plays a 'level up' style jingle.

Links to the parts:
Mi:power case htt…