Brad Ormand - Audio Tool Main Breadboard

10.14.2014 – SSD1306 & Time Clock

I spent at least 5 hours yesterday writing the driver for my OLED display, and designing the backbuffer characteristics and manipulations.. However, I couldn’t get it to turn on!!! Ugh! It was then when I figured out that I had been looking at the SSD1308’s datasheet, and not what I really had, which was the SSD1306! I don’t know how I got that confused. Plus, it had a separate circuit on the back built-in that acts as a charge pump where you can use the Vdd to drive Vcc, and it also has a startup routine!! I did not know this.

It was late last night that I discovered this when I went back to my receipt (and earlier posts) and saw what version I had. And, also the name, “SSD1306” is the name of the controller connected to the actual OLED array – good enough for me to just call it that, though. It’ll be whom I will be talking to, anyway 🙂 . They look exactly the same (as far as I know) Oh well – it’s another learning experience to drop in the bag. I began the 1306 power on sequence with included charge pump last night in C with HW SPI.

And, in other news, I tested my “accurate” time clock… Yeah – it was way off. Ha. It varies by 15 minutes per month, or about a second per hour. So… maybe that source 8MHz has a bigger tolerance than I thought (or maybe I’m just wrong [again! ugh]). I know I could get a watch crystal to drive it, but no.. I wanted to see how accurate I can get without one. But, for production applications – I don’t think the on-chip clock is accurate enough for long term counting, if this is the case.