Monday 18 May 2015

Poor Man's Through-Hole PCB Rivet

First of all I have to thank Retromaster for his descriptions on how to do through-hole contact riveting. My double-sided prototype PCBs are done on a CNC Router but originally I was using just flexible wire soldered on both sides of the PCB. This method I found just created big solder bumps , not much good for surface mount IC's with through-hole contacts directly under them. So to remedy this situation I used a drill press with a 3mm stainless rod mounted in the Chuck. I put short pieces (approx 2.6mm long = thickness of PCB 1.6mm + Protrusion on each side of PCB 0.5mm X 2  ) of tinned copper wire whose diameter  matches closely the diameter of the via hole into the via for the through-hole connection. I positioned the 3mm rod in the chuck over the via to be riveted with the copper wire in the hole and gently rotated the drill press capstan. This pressed the copper wire into the hole. I relaxed the pressure on the PCB to allow the balancing of the head size of the rivet on both sides of the PCB. Below is a photo of some practice rivets and one via not riveted on a scrap PCB for practice, these rivets will have a light soldering using solder paste to ensure a good electrical connection. I am very pleased with this method of connecting vias on PCB prototypes.

Riveted through-hole connections


Thursday 5 March 2015

BT Infinity and my HG612 VDSL2 Modem Firmware Upgrade

Speed kbps
My Home Download Speed
Warning: If you attempt what I describe here you may reduce your modem's usability to that of a brick , remember you are in charge of your own destiny. Note: I have two modems one for experiments and the other as backup.
 
I have been in the habit of using a Raspberry PI to log my ADSL2+ then VDSL2 speeds for a while now. The graph above is the speed of my ADSL2+ until I got BT Infinity or FTTC (Fibre To The Cabinet) , the time is about a year in span and speed is in kbps. Point A is when my ADSL2+ speed a took a dive due to a tree wearing through my overhead telephone line. It took BT about a full month to fix the fault and remove the subsequent speed cap at Point B , it took two emails to the BT Community Forum to get them to remove the cap even though they said that it had been removed , it hadn't.
Between Point B and C you can see my speed was unstable with my router continually dropping connection and then re-syncing at different speeds. You can see how unstable it was even after the line repair compared with the lead up to Point A , perfect. I then had BT Infinity installed at Point C using a BT Openreach Huawei EchoLife HG612 modem with unlocked firmware. This allowed me to log speeds , it isn't something that is enabled by default with BT's stock modem.
Between Points C and D it is not very stable speed wise , I have a long wire to the cabinet hence the lower than anticipated VDSL2 speed. So eventually I got a bit fed up with the variability of the connection speed so I tried new firmware in my modem , this firmware has a newer binary blob driver for the Broadcom modem chipset. Point D shows the time the modem had the new firmware flashed , it is a higher speed and also very stable , fantastic. So the only thing that has changed is the firmware change on the HG612 at point D. This also just shows that the digital signal processing elements have been improved in this binary blob driver.  Now I'm very impressed with the latest firmware for this modem , but it's a shame I've had to do all this firmware upgrade myself and that BT don't seem to be continually improving their modem firmware. This even though they do have BTAgent enabled to update firmware themselves.
I have BTAgent disabled because I don't want them to disable my logging system with their new firmware. They seem more concerned with not allowing their customers to actually see how bad their broadband connections are by disabling useful functionality. It has been noted by others that some of the BT firmware updates rolled out via BTAgent have disabled Web Configuration and telnet access to these modems.
Hope this helps you.

Defender 300tdi Lucas 10AS Alarm Immobiliser (Spider) Problems

We have a 1997 Landrover Defender 300tdi that has given immobiliser problems intermittently. I had initially fixed the fuel solenoid as we w...