Tuesday, April 24, 2018

More SONFF, Node Red, and MQTT testing

Below is my simple lash up of the DHT-11 sensor to the basic SONOFF switch using the unused GPIO. I am powering it via the FTDI board. This works great for the sensor and LED on the SONOFF but does not fully operate the relay. I did this so I could range test the Wifi and actually had it powered by a USB battery pack. The range was great, good signal in the house and back yard.
The Node Red UI screen below shows the use of the chart function to plot the WiFi signal level and DHT-11 temperature. The Node Red code is HERE

Tuesday, April 3, 2018

SONOFF Wireless switches, Node-RED, Tasmota, and MQTT

I have been busy playing with SONOFF wireless switches, both the Basic and the 4CH. I have developed some Arduino IDE based firmware for both devices here on GitHub,

I am also looking at an alternative to OpenHAB for home automation using Node-RED (the coolest software I have ever seen to date) and MQTT Mosquitto all running on Docker. I am running it on a PC with Vagrant but I would like to move it to Raspberry Pi Zero W. The idea being two or more running a Docker swarm for the Node-RED and MQTT services. I want to figure out a way to make it highly available using something like Keepalived. My Node-RED flows are here onGitHub. Today I just loaded the alternate firmware for the SONOFF's --> Tasmota. It is very powerful. So far I got the MQTT mode working with Node-RED and I added a DHT11 sensor (super cool).

Wednesday, January 24, 2018

Digi-Comp I v2.0

This last weekend I built my Digi-Comp I v2.0 which is a replica of a Digi-Comp I which was first released back in 1963.

The Digi-Comp I v2.0 available from Minds-On Toys is made of cardboard verses the plastic of the original. Since originals are hard to come by, this is good alternative. I am still tuning it mechanically but the picture above is basically alternately toggling the A and B flip-flops. It is of course hand operated and the GIF is stop motion without my hand in view :-).

It is great entertainment to researching vintage computing toys and actually being able to own one and build it, to understand it with your own hands is even better.

Tuesday, July 11, 2017

Camper Build IX

The basic build of the folding camper is complete. The panels are insulated and I have begun painting. I decided not to fiberglass. I am using a high quality house paint, The painting and finishing takes time and you can spend as much or as little on it, but it is directly proportional to how it will look in the end. I am trying to strike a balance because I want it get it on the truck and use it soon.

The top, front and side panels will be ultra white. It is taking between 3 and 4 coats to get good thick coverage. The bottom half and underside will be either black or desert tan, maybe forest green, I am still deciding. The inside may not get painted until I use it a few times but I plan to urethane the floor. The interior walls may be what ever color of extra paint I have from other house projects :-)

Sunday, June 11, 2017

APRS Touch Tone Gateway

I have been playing with WB2OSZ Direwolf software, it is very powerful and can act as a APRS Touch Tone gateway. His software ia located HERE.

I was able to get his code working under windows and using the DTMF decoder it is decoding my 10 digit call sign and a two digit message. This is a new configuration idea suggested by the father of APRS WB4APR, see the new idea below. I just set mine up on a simplex radio for testing.

-----------Bob's new idea! --------------
But here is the NEW idea of how to use its 2 digit message capability
1) Have it listen from a very high central metro area location for DTMF on
2) The two-digit messages (01 to 99) can be used to trigger the APRS and
voice response of "CALLSIGN, LISTENING ON XXX.XXX MHz"
3) then ALL APRS mobiles in the area will see the message on their radios
4) AND he messages goes worldwide in the APRS-IS system
5) You could be called back via Echolink for example
6) AND if anyone is monitoring 146.58, they will hear EVERYONE on the air
and where they are listening.
In our area with over 50 repeaters, we are so spread out, hardly any
repeater is being used. But this way, everyone's "presence" on the air is
announced on APRS and the single 146.58 just like APRS was always intended
to be... a single clearing house channel for everything happening in ham
But now you only need a DTMF radio. Not a full APRS rig.
Oh, we just make a local list 01 to 99 of the different frequencies. Every
local list is different, but so are the repeaters in every local area...
Though I am starting to think it can be quite universal! Wow, Il start
now... for example 76 is 146.76 and 94 is 146.94, etc!
You just program your DTMF memory with the few repeaters you use, and then
sending out your message is just one button. Send the DTMF memory with
your chosen "monitoring frequency!
for more info on APRStt see http://aprs.org/aprstt.html
Bob Bruninga, WB4APR
USNA Satellite Lab

Camper Build VIII

It has been a while since I posted in general and regarding the camper build. The build continues  a bit each weekend with the following progress:

  • Windows with slider inserts completed
  • Insulating of the top and sides
  • Paneling of the front with door and one side
Here are the windows with screens in, looking in one to the other.

Here is the basic assembly of the windows using the synthetic wood trim material and the slider guides that are glued to the synthetic wood.

This is the black plastic sliding door tracks I am using that I got from Rockler

I am finishing up all the insulating with the R-TECH foam.

Here is the door insulated and sided with 2.7 mm thin door skin plywood.
Here is one of the sides insulated with the inside sidinging.
Once I finish the insulation and interior paneling I will begin the exterior finish. I am planning on a light epoxy fiberglass coating and then paint. I still need to work out the door latch assembly and the general weather sealing.

I am hoping to try it out camping in the late summer as well as fall/winter since it is insulated.

Monday, April 17, 2017

Retro Computer Fun

For the last couple of months I have been playing with some Retro Computers.

I thought CP/M and the various tools on a tiny computer like the Teensy 3.6 would be a perfect low powered non-Internet computer various projects and to be portable. However I still needed a terminal to use CP/M and I wanted some minimal graphic capability too. In search of a small dumb terminal board I stumbled in the the world of Maximite HERE and MMBasic created by Geoff the genius!

I am now using a Maximite clone (CGCOLORMAX2). It can drive a VGA or composite display directly with great graphics along with a SD card based flash file system, real-time clock and I/O capability. Recently I have been digging into the power of Geoff's MMBasic that runs on the CGCOLORMAX2 (which uses a PIC32). Even though it is a single precision version of BASIC I have had great success in porting some mathematically intensive astronomy programs.

I have setup my CGCOLORMAX2 to run with a small 4.3 TFT LCD composite display used for backup cameras. The only thing else needed is a PS2 keyboard and DC power to run the board and the monitor (e.g. 12 volts). This setup is running great so far and will do some power consumption tests soon to size the battery pack to make this portable.