Wednesday, 3 December 2014

Trying to read from a linear CCD

I found some more time to play with the linear CCD that Billy had sent me. If you remember last time, I'd managed to get a working clock signal and I could "see" the output on an oscilloscope. In some ways, that was the easy bit! Actually getting the output into a digital form is harder than it looks.

Thursday, 30 October 2014

Dead ScoutGuard & bargain Bushnell

Any plans I had for hacking the ScoutGuard came to an abrupt end recently when this happened:

Yes, I managed to not only lift the track off the PCB but also break the pin off the PIC. The camera was misbehaving quite badly before this incident anyway and I was getting close to calling it a day but this is one of those annoying mistakes that forced my hand. There is still sufficient track left to tap into, it is the minimal pin leg on the PIC that is the real issue.

Friday, 10 October 2014

(Ab)using CurrentCost dev boards - code

This is something that I've been meaning to do for a while. I put together a "framework" to deal with the common tasks with the CurrentCost digital development boards, such as transmitting and pairing. I've also provided an example of handling a DHT22 temperature and humidity sensor.

Tuesday, 7 October 2014

Hacking a ScoutGuard camera - part 4

The plan for the forth instalment in this series was to extract the firmware from the flash, hack it around to remove the logo and write it back. This was going to provide the opportunity to play with the TSOP clip I'd finally got around to ordering, as well as a few other bits and pieces required to read from the chip in circuit.

Unfortunately there was a bit of down time while waiting on the clip to arrive. This was sufficient reason to justify poking around with the PIC16F684 chip that is used to read the sensor data and take the photo. I had probed the pins with the scope and could see the data coming in from the PIR and the trigger control going high after a certain amount of time and this data alone could have been useful to start playing about with. The temptation to look at the data from the chip was too great however, and I preceded to hook up my PICKit in an attempt to see if I could get a dump of the code. I knew the likelihood of this was pretty small, but nothing ventured nothing gained.

Sunday, 5 October 2014

Fun with a Linear CCD

Some time back, Billy gutted a USB scanner, so he could grab the fun parts like mirrors, steppers etc. He sent me the board with the sensor on it, in the vague hope I might be able to do something with it. Sadly, I didn't take a picture of the original board then. Initially, I looked over the board, and could identify the memory, the scanner USB chip, and the fact there was a linear CCD onboard. After figuring out there wasn't anything much I could do quickly, it sat on the side for a while. Eventually, I figured that I should do something with it, and if I was going to do anything with it, I'd need to figure out how to interface with the CCD. If nothing else, I figured this would be a good learning exercise.

Wednesday, 23 April 2014

(Ab)using CurrentCost dev boards part 4

Last time around, I'd managed to get as far as starting and stopping the transmitter. I also alluded to the fact that it was slightly more difficult than I'd expected! I also needed to tap the receiver in order to see what's going on! First thing, in order to be able to see that we've transmitted valid data, we need to be able to receive. The CurrentCost EnviR base is already set up correctly for receiving, which should make life easier. So, we need to take the receiver apart and see what we can find.

Hacking a ScoutGuard camera - part 3

In the previous posts [1] [2] I mentioned that the ultimate goal was to load modified firmware on to the device and one possible route would be via JTAG. It was hoped that the test points in the bottom left corner would provide JTAG access:

Wednesday, 22 January 2014

Ericsson PTF-118 pager teardown

A recent ebay score was a job lot of 5 Ericsson pagers for the grand total of £10. The 'buy it now' temptation was too great and before I'd had a chance to look into the feasibility of getting these 90's era devices to do anything fun it was too late, I'd clicked the button.

Between committing to buy and the devices arriving, I'd managed to at least figure out that there are plenty of warning pages on ebay explaining that BT pagers will no longer work. Looking back, the seller had cunningly covered the blatant BT logo on the top right of the box with convenient positioning:

Wednesday, 15 January 2014

Linksys EG008W switch repair

I've had a Linksys EG008W Gigabit ethernet switch for some time now, and other than a noisy fan and no jumbo frames it has worked pretty well over the last seven years or so. It comes in a case that's rather definitive for Linksys.

Sadly, in the last few days it has started acting up in the form of random resets. It's now got to the point where it's spending more time in reset than switching, which makes it rather useless unless you want a notwork. So, now's a good time to tear it apart!