I have been hired for a new job with the Xbox hardware design team. I will be doing a lot of moving and paperwork in the next few weeks, so updates might be far and few. I don’t know what the schedule will be like with the new job, so here’s to hoping that the website will still be updated regularly.
In addition, I’d like to share an IR oven design in the next few updates. Last year, I required the soldering of some parts that were impossible to mount using a solder iron. Instead of outsourcing a few prototype parts, I decided to build my own IR oven. Since the software has been relatively stable, I think it’s time to share the design with anyone interested. Updates to come when I have time to post pics and code.
The second part of the keypad door access circuit is now also available. This section deals with writing drivers for a scanning keypad.
So haven’t heard from me in a while. I am back, and hopefully with some interesting stuff to post.
I just realized that I don’t post a lot of analog circuits on my blog and I’d like to expand on the subject matter a bit more. Analog design involves a lot of calculations and noise mitigation which, in this day of digital signal immunity, doesn’t get quite the attention it deserves. To kick things off, I’ve added a solenoid circuit that works off of USB in the Tips and Examples section. Enjoy.
Played some more with the circuit and I connected the output to the Macbook Pro panel today. Surprisingly the Macbook Pro panel (made by LG) is a lot brighter and uses less power than the Dell (made by Samsung). Although to be fair, the Macbook Pro Panel was released about 3 years ago, whereas the Dell panel was released 8 years ago. The panel is extremely bright and the white LED backlight drivers seems to be working correctly. A picture below.
The hardest part of the whole thing? Apple demanded such small connectors from the LG panel. It’s hard to break out the leads out to my circuit. The circuit design was surprisingly simple. More to come.
I have finally come around to finishing the laptop monitor driver that converts HDMI signals into LVDS. I’ve included some pictures of the circuit functioning.
Below is an laptop screen of an old Dell D830 that I took apart. There was very little documentation on the backlight driver, so I had to reverse engineer the signals from the laptop to figure out how it worked. It turns out it uses a Maxim controller chip, requiring I2C communications.
The screen is not very bright (chromometer gun reads about 25 ft-L), so I was worried that I had connected something wrong. However, I took a working Dell D830 laptop and measured the brightness with the color gun to compare and it was about the same at the maximum brightness.
Here’s a photo of the circuit I created. The LVDS signals are all wired by hand and soldered onto the LTN154P3-L05. The wires are short enough such that the signal integrity does not degrade severely. Total power consumption is about 10W, which isn’t bad. I’ve included an LED driver on the circuit so that it can power the MacBook Pro panel, which is also sitting in my lab. The Dell uses a CFL backlight. I’ll post a more comprehensive write up when I have time and when the project is nearer to completion.