Journey's End

Oct 27
2023

DIY EQMod Direct USB Cable

I am in the process of resurrecting my Eq5 Pro so it is compatible with ASIAir Mini. The first step is to build an EQMod Direct USB cable. While it is possible to buy one pre-made, since I had all the parts I decided to build it myself.

Based on the reference document I need to make an single-ended RJ45 cable. I followed T-568A colour scheme:

Based on this colour scheme, the connection to a USB-UART adapter is as follows:

RJ45 Colour USB-UART
4 Blue Ground
5 Blue-White RXI
6 Orange TXO

Plug the RJ45 end of the cable into the hand-controller port on the control box and the other end into the ASIAir Mini. Then power up the ASIAir Mini as usual and use one of the 12V outputs to power the SynScan. Make sure to switch on the SynScan as it has its own power switch. After this select EQMod for the mount model and leave the baudrate at the default value of 9600. Tap the enable-toggle-switch and the ASIAir Mini will attempt to connect to the mount. After a successful connection you should be able to manually slew the mount in RA and DEC in Preview mode.

Update: I have to power up the SynScan after the ASIAir has fully booted (made it's beeping noises) in order for them to communicate successfully. If both are powered up at the same time, something goes awry and the ASIAir Mini will not be able to connect.

ts=04:34 tags=[electronics,diy,astronomy]

Sep 17
2023

Build Log: SCD41 CO2 Sensor

CO2 concentration is a proxy for how well a space, especially an enclosed one, is ventillated. To this end I build a quick-n-dirty CO2 sensor using a SCD41 breakout board from pimoroni and bits and pieces I had in the workshop.

Took the opportunity to practice making enclosures, especially for …

ts=14:21 tags=[electronics,arduino,diy,cad,freecad,3dprinting]

Apr 23
2012

Notes on RF-0417C

Some notes on using the popular Bluetooth serial module RF-0417C:

  • When sending AT commands, do not include \r\n either together or singly.
  • It appears to be happy to receive 5V inputs to TX.
  • It is not happy to receive 5V to Vcc.
  • If you connect a LED, it blinks …
ts=12:13 tags=[electronics,arduino,diy]

May 07
2011

Success for Science

Just finished packaging my engineering thesis project into a more portable format: an altoids tin! I have seen people put some neat stuff inside them, and I am chuffed I managed to as well :) Though I had to cut through the lid for the display. And I only had to …

ts=12:23 tags=[electronics,arduino,diy]