Category: Projects

Frustration pt. 2

I fixed a wiring error on the board I was having problems with. I now get 2 of the 3 outputs I expect to get from the chip. The ADC is giving me the BCLK and the LRCLK that I expect but I still don't see any data on DOUT.

I'm using an electric guitar as my analog input. This has two implications for me: first, the signal from the guitar is a pretty low-level analog signal. This shouldn't prevent me from seeing data coming from the ADC, however. The other problem is that I need to strum the guitar to generate a signal, and strumming while holding an oscilloscope probe can be an exercise in manual dexterity. I'm thinking of building an analog waveform generator to use as a test input signal while I do further troubleshooting.

I'm going to pore over the datasheet to try to figure out why I'm not getting any output on the DOUT pin. Hopefully I missed something simple.

Frustration

How do you deal with the frustration of prototyping a circuit, only to find that it doesn't work as you expected it to?

I'm prototyping a circuit for the Renesas RX Design Contest that uses the Texas Instruments PCM3060 audio CODEC. I'm basically copying someone else's schematic. And I can't get it to work as expected. I'm feeding the CODEC a clock signal but it's not giving me any data from the ADC. I etched two circuit boards and both have the same behavior. I don't know what the problem is. Did I wire it wrong? Did I damage the chips? I don't know.

Very frustrating. Very demoralizing. In times like this I think of all the time and effort I put into a design and prototype, and the frustration that it gets me, and wonder why I do it.

Hopefully I'll get an answer to the question I posted on TI's forums about this problem. I don't know how to make any progress from where I am now.

Breaking the 8/16 Bit Habit

I have submitted my video online for a free NXP LPCXpresso board. If NXP awards me one of these dev kits, you can bet that it'll show up in future episodes of The Hacker Workshop. NXP makes a lot of cool 32 bit processors and I'd probably be working on one of them now if Rensas hadn't wooed me away with the RX Design Contest. Submit a video of yourself destroying an 8 or 16 bit processor, and you too could end up with a free LPCXPresso board!

First MSP430 Launchpad Project

In case you're not aware of it, Texas Instruments has a value line of microcontrollers, the MSP430 line. They have a starter kit called the Launchpad and they're practically giving these things away! The Launchpad costs $4.30 and that includes shipping! You can order three at a time from TI's online store (registration required).

The MSP430 is not a particularly powerful microcontroller, but for the cost it's definitely worth getting and playing with. One nice thing is that it's a 16 bit controller so it's able to crunch numbers a little faster than an 8 bit proc. Be sure to download the Getting Started Guide, as the datasheets are really not terribly useful to a beginner. TI did a pretty good job with the labs in the Getting Started Guide.

Here's a video of my first project. I did this in a few hours of studying and coding, but then again I have some experience working with other microcontroller families that helped me get up to speed more quickly. In future videos I'll go over the Launchpad and the MSP430 in more detail, and we'll dissect the code I used to create this project.