Sometimes you might run into a situation when one or more of your I2C devices don’t work. I deal with barometric pressure sensors in my work and these work on the I2C bus. I’ve been banging my head against the wall many times over simple things and mistakes, and that’s why I decided to share some of that “wisdom”. Continue reading
When you design PCBs for work, cost-effectiveness is a big factor. To help you out in the that department, you usually design your board to be a big panel. This panel is then CNC routed to contain a V-groove. This is as the name implies, a V-shaped groove that runs between the individual boards on your panel. When you have pasted, stuffed and reflowed your boards you simply snap them off. This brings in the cost-effectiveness, to be able to process many tens of boards at once. Continue reading
As a part of my work, I wrote this simple I2C address probe. It’s for PIC microcontrollers, using CCS compiler. (It’s here mostly as a note for myself, but you might find it useful as well.)
I’m disabling comments for now. I get two to three spam comments a day, which isn’t much by itself, but I get a notification on my phone every single time. That’s annoying.
For spammers: don’t waste those poor Indian people’s time on solving reCAPTCHA’s for my site. No one of your stupid spams have ever got through.
If you wish to contact me, my account is mristila and the email server is gmail.com.
When I design PCBs I use millimeters for drill sizes, component pad distances and sizes and for board outlines. Somehow I ended up using mils for trace widths and clearances. This doesn’t really make sense, and now I decided I would move to millimeters altogether.
To help me in this, I made a simple lookup table from mils to millimeters and back. I also included ITead Prototype PCB service rules since I think many hobbyists order their PCBs from ITead. Below you can find links for the PDF as well as the original Excel sheet, so you can modify it to your liking. If you like it, or find any mistakes, please leave a comment! Continue reading
I’ve made progress with AmbiHDMI. The PCB shipment is on its way from China, and it should arrive early next week (I hope!). UPS dropped off a package from Farnell today. See, I was contacted by Farnell a few weeks ago. They offered to ship me a few items in exchange for a review. I asked for a couple of ADV7611 HDMI receivers and a couple of HDMI receptables from TE Conn. The packaging was totally overkill but atleast all the four bits made it from England to Finland in one piece! Continue reading
I bought a Samsung SCX-4200 around five years ago. I was just starting my engineering studies and figured I’d need a printer. Searching around for a suitable candidate, the SCX-4200 popped up. In addition to being a USB-connected laser printer it was also a scanner-copier. I think it cost 160 euros back then, so it was perfect for a poor student. The toner cartridge ran out after a year and in the end I didn’t really need a printer since I could do all my printing for free at school anyway. The scanner has seen twice the action than the printer part ever did.
I thought I’d write something here for a change. I have a pretty short attention span when it comes to my free time projects, but all the projects progress at some pace nevertheless. A lot of ideas marinate in my head all the time and when the right time comes, they start materializing. Anyway, enough babbling, here is my list of on-going projects in no particular order.
(This is an English translation of my article at Ruuvipenkki forum.)
In this article I will discuss my own experiences about designing a USB sound card, which is the USBDAC. DAC is an acronym for Digital-to-Analog Converter because in a sound card, digital data representing the sound is converted into analog voltage that moves the speaker cone.
My device is loosely based on the PCM2706 reference design. I will not go through the tecnical details but instead concentrate on my own experiences in the design of the device. This is to keep people not familiar with electronics, as well as newcomers to electronics design, interested. You will see that one working product is the result of many failed prototypes.
I’ve had the HTC Desire since October 2010 IIRC. Back then, Android 2.2 was all the rage. I was very happy with it. Soon later, Android 2.3 was released and all Desire users eagerly anticipated the arrival. HTC eventually delivered… about half a year behind schedule and only to encourage only experienced users to try it out since they couldn’t make the whole Sense UI fit in. Needless to say I was pretty frustrated with HTC’s solution. Another half year passed by and I really wanted something fresh. Either a new phone or a new ROM for the old Desire. Continue reading